WO2014126187A1

WO2014126187A1 - Image processing device, image processing method, image reading device, and program

Info

Publication number: WO2014126187A1
Application number: PCT/JP2014/053430
Authority: WO
Inventors: 聡山中; まさ子浅村; 善隆豊田
Original assignee: 三菱電機株式会社
Priority date: 2013-02-18
Filing date: 2014-02-14
Publication date: 2014-08-21
Also published as: JP6058115B2; JPWO2014126187A1

Abstract

This image processing device (1) has: a similarity calculation unit (42) that calculates the similarity between comparison data and baseline data in an overlap region using first image data generated by a first column line sensor group and second image data generated by a second column line sensor group; a shift amount estimation unit (43) that calculates shift amount data on the basis of the position in the sub-scanning direction of comparison data having the highest similarity; and a linking processing unit (44) that links the first image data and second image data by altering the linking position in the sub-scanning direction on the basis of the shift amount data.

Description

Image processing apparatus, image processing method, image reading apparatus, and program

The present invention relates to an image processing apparatus, an image processing method, and an image reading apparatus that combine image data obtained by scanning a read object with a plurality of line sensors to generate composite image data corresponding to the read object. The present invention also relates to a program for causing a computer to execute processing for combining the image data.

An image reading apparatus that scans a reading object with a line sensor (one-dimensional imaging element) having a plurality of imaging elements arranged in a line in the main scanning direction and generates image data corresponding to the reading object is a copying machine, Widely used in scanners and facsimiles. As a typical example of an image reading apparatus, a contact image sensor type apparatus that closely contacts a line sensor to an object to be read and a reduced transfer type that generates a reduced image of the object to be read by a reduction optical system and reads the reduced image by the line sensor. There is a device with. The contact image sensor type apparatus has an advantage that it can be easily downsized, but has a disadvantage that the depth of focus is shallow. On the other hand, the reduction transfer type apparatus has an advantage that the depth of focus is deep, but has a disadvantage that miniaturization is difficult.

Therefore, an image reading apparatus that can be easily downsized and has a large depth of focus has been proposed in, for example, Japanese Patent Application Laid-Open No. 2009-246623. The image reading apparatus includes a first row line sensor group and a second row line sensor group including a plurality of line sensors arranged at intervals in a line in the main scanning direction, and a first row line sensor. A telecentric optical system that forms an erect image on each of the group and the second row of line sensor groups.

The image reading apparatus includes a plurality of images generated by scanning a plurality of first row line sensors belonging to the first row line sensor group and a plurality of second row line sensors belonging to the second row line sensor group. The sub-scanning direction between the image data of the line sensor of the first row and the line sensor of the second row using the image which the line sensor of the first row and the line sensor of the second row read from the data in an overlapping manner Is obtained, and the position of the image data in the sub-scanning direction is shifted in accordance with the obtained amount of positional deviation, thereby generating composite image data corresponding to the object to be read.

JP 2009-246623 A (paragraphs 0047 to 0049) JP-A-6-22158

However, in the image reading apparatus of Patent Document 1, the following processing is performed when generating the composite image data.
(Process 1) First, the position in the sub-scanning direction of the divided image indicated by the image data generated by the first line sensor from one end side (for example, the left side) of the line sensor group in the first row is used as a reference. Thus, the position in the sub-scanning direction of the divided image indicated by the image data generated by the first line sensor from the left side of the line sensor group in the second row is shifted.
(Process 2) Next, from the left in the first row of line sensor groups, the divided image indicated by the image data generated by the first line sensor from the left in the second row of line sensor groups is used as a reference. The position in the sub-scanning direction of the divided image indicated by the image data generated by the second line sensor is shifted.
(Process 3) Thereafter, the line sensors to be processed are changed one by one to the right, and the same processes as those in Process 1 and Process 2 are repeated.
As described above, when the processes 1 to 3 are performed in order, every time the line sensor to be processed moves to the other end side (for example, the right side), the image data generated by the adjacent line sensor indicates. Misalignment in the sub-scanning direction of the divided images is accumulated, and it may be difficult to align the position of the image data in the sub-scanning direction on the other end side (for example, the right side) of the line sensor.

Also, for example, in a copying machine having a reduction / enlargement function, a document reading magnification (hereinafter also referred to as “variable magnification”) according to the copying magnification, as in the case where the scanning speed in the sub-scanning direction (sub-scanning speed) changes. ), And an image is read by enlarging or reducing the image (hereinafter also referred to as “performing scaling process”) (for example, see Patent Document 2). When scaling processing is performed, the number of pixels read in the sub-scanning direction (that is, the number of read lines read by the line sensor) is equal to the number of lines when the scaling factor is 1 (that is, 100%). The number of lines multiplied by the scaling factor R is scaled (that is, enlarged or reduced). As a method of changing the magnification ratio from 1 to R times, the relative movement speed between the document and the line sensor (or the document and the document sensor) while the reading cycle (line sensor drive timing) by the line sensor is constant. A method of changing the relative movement speed between the optical system and the optical system to a relative movement speed of 1 / R of the relative movement speed when the magnification is 1 is common.

When scaling processing is performed, the number of lines (hereinafter also referred to as “reading lines”) read by the first row line sensor and the second row line sensor (hereinafter also referred to as “line number”) depends on the scaling factor. Changed. The number of lines read by the line sensor when the variable magnification R is R ₀ times (R = R ₀ ) is the number of lines read by the line sensor when the variable magnification R is 1 time (R = 1). R ₀ times compared to For this reason, when the enlargement / reduction processing is performed in the image reading apparatus of Patent Document 1, the image data of the image read by the first line sensor and the image data of the image read by the second line sensor are used. The amount of misalignment in the sub-scanning direction (number of lines) between them increases according to the magnification ratio R.

When determining the amount of positional deviation in the sub-scanning direction between the image data of the image read by the line sensor in the first row and the image data of the image read by the line sensor in the second row, The first column in the range from the position in the scanning direction to the farthest position for detecting the amount of positional deviation for shifting the position in the sub-scanning direction, that is, in the search range for detecting the amount of positional deviation. Both the line sensor in the second row and the line sensor in the second row perform processing for detecting the position in the sub-scanning direction in which the same image (that is, the image having the highest similarity) is read in the overlap region. However, in the enlargement / reduction processing in which the enlargement / reduction ratio R is larger than 1, the image data of the image read by the line sensor in the first row and the image data of the image read by the line sensor in the second row When determining the amount of positional deviation (number of lines) in the sub-scanning direction, the number of lines included in the search range is included in the search range in the scaling process when the scaling ratio R is 1 When the number of lines is the same as the number of lines to be generated, the search range is too narrow and the following problem may occur. For example, the position in the sub-scanning direction where the image data matches in the overlap region between the image data of the image read by the line sensor in the first row and the image data of the image read by the line sensor in the second row Is not detected within the search range, and the amount of positional deviation in the sub-scanning direction between the image data of the image read by the line sensor in the first row and the image data of the image read by the line sensor in the second row ( The number of lines) cannot be obtained with high accuracy. For this reason, in the enlargement / reduction processing, in order to detect the positional deviation amount in the sub-scanning direction with high accuracy, the search range for detecting the positional deviation amount (number of lines) is expanded in accordance with the magnification ratio. It is desirable to increase the number of lines.

However, in order to expand the search range for detecting the displacement amount according to the magnification, it is necessary to switch the content of the displacement amount detection process according to the magnification, which is necessary for the displacement amount detection process. There has been a problem that this leads to an increase in circuit scale.

An object of the present invention is to subdivide a divided image indicated by image data generated by a line sensor belonging to the first row line sensor group and a divided image indicated by image data generated by a line sensor belonging to the second row line sensor group. Image processing apparatus, image processing method, and image reading apparatus capable of generating high-quality composite image data corresponding to an object to be read by a processing procedure that does not accumulate positional deviation in the scanning direction, and combining the image data It is to provide a program for causing a computer to execute processing to be performed.

Another object of the present invention is to eliminate the need for expanding the search range for detecting the amount of positional deviation in the sub-scanning direction between the image data of the line sensors in each column even when the reading magnification is changed. There is no need to change the content of the amount detection processing, the amount of positional deviation can be obtained accurately without increasing the circuit scale, and an image processing apparatus, an image processing method, and an image processing method capable of generating high-quality composite image data, And an image reading apparatus, and a program for causing a computer to execute processing for combining the image data.

An image processing apparatus according to an aspect of the present invention includes a first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and the first row of the first row sensors. An image pickup including a line sensor group and a second row line sensor group including a plurality of second line sensors arranged at different positions in the sub-scanning direction and arranged in a line at a second interval in the main scanning direction. The plurality of first line sensors belonging to the first row line sensor group are arranged to face the second interval in the second row line sensor group, and the second row The plurality of second line sensors belonging to the line sensor group are arranged so as to face the first interval in the line sensor group of the first row, and the adjacent first line sensor and the second line sensor group Adjacent to the line sensor An image processing apparatus that processes image data generated by the imaging unit having an overlap region in which ends overlap in the main scanning direction, and is based on a detection signal generated by the first row line sensor group An image memory for storing second image data based on the first image data and a detection signal generated by the second row of line sensor groups, and the first image data read from the image memory Selected from the reference data having a predetermined first width in the sub-scanning direction in the overlap region and the second image data read from the image memory in the same overlap region. The comparison data having the same width as that of the comparison data is processed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data A similarity calculation unit for calculating the similarity between the comparison data and the comparison data, the position of the reference data in the sub-scanning direction, and the comparison data having the highest similarity among the plurality of comparison data in the sub-scanning direction A shift amount estimation unit that calculates shift amount data based on a difference from the position; and reads out the first image data and the second image data from the image memory, and divides the shift amount indicated by the shift amount data. Generating first shift amount data indicating one of the divided shift amounts and second shift amount data indicating the other divided shift amount, and generating the shift amount data based on the first shift amount data. The position of the first image data in the sub-scanning direction is corrected, the position of the second image data in the sub-scanning direction is corrected based on the second shift amount data, and the first image data and the Second image data And a combination processing unit for combining the data.

An image processing method according to another aspect of the present invention includes a first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and the first row. And a second row of line sensor groups including a plurality of second line sensors arranged at different positions in the sub-scanning direction and arranged in a line at a second interval in the main scanning direction. The imaging unit, wherein the plurality of first line sensors belonging to the first row line sensor group are arranged to face the second interval in the second row line sensor group, and The plurality of second line sensors belonging to a line sensor group in a row are arranged to face the first interval in the line sensor group in the first row, and the first line sensor and the second adjacent to each other. Adjacent line sensors An image processing method for processing image data generated by the imaging unit having an overlap region in which the end portions overlap in the main scanning direction, the detection signal generated by the line sensor group in the first row Of the first image data read out from the image memory storing the first image data based on the second image data based on the first image data based on the detection signal generated by the line sensor group in the second column, and Same as the first width selected from the reference data having a predetermined first width in the sub-scanning direction in the overlap region and the second image data read from the image memory in the same overlap region A process of comparing the comparison data with the width is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, and the comparison with the reference data is performed. Based on the difference between the position in the sub-scanning direction of the reference data and the position in the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data Calculating the shift amount data; reading out the first image data and the second image data from the image memory; and changing the coupling position in the sub-scanning direction based on the shift amount data. And a step of combining the image data and the second image data.

An image reading apparatus according to another aspect of the present invention includes a first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and the first row. And a second row of line sensor groups including a plurality of second line sensors arranged at different positions in the sub-scanning direction and arranged in a line at a second interval in the main scanning direction. The imaging unit, wherein the plurality of first line sensors belonging to the first row line sensor group are arranged to face the second interval in the second row line sensor group, and The plurality of second line sensors belonging to a line sensor group in a row are arranged to face the first interval in the line sensor group in the first row, and the first line sensor and the second adjacent to each other. Adjacent line sensors First image data based on detection signals generated by the first row of line sensor groups, and the second row of line sensors. An image memory for storing the second image data based on the detection signal generated by the group, and a predetermined value in the sub-scanning direction in the overlap region of the first image data read from the image memory. Processing for comparing the reference data having the first width and the comparison data having the same width as the first width selected from the second image data read from the image memory in the same overlap region Is performed on a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, and a similarity calculation unit that calculates the similarity between the reference data and the comparison data A shift amount estimation unit that calculates shift amount data based on a difference between a position in the sub-scanning direction of the reference data and a position in the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data; The first image data and the second image data are read from the image memory, and the first image data and the second image are changed by changing the coupling position in the sub-scanning direction based on the shift amount data. And a combination processing unit that combines data.

A program according to another aspect of the present invention includes a line sensor group in a first row including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and a line in the first row. An image pickup unit having a sensor group and a second row of line sensor groups including a plurality of second line sensors arranged at different positions in the sub-scanning direction and arranged in a line at a second interval in the main scanning direction The plurality of first line sensors belonging to the first row line sensor group are arranged to face the second interval in the second row line sensor group, and the second row The plurality of second line sensors belonging to a line sensor group are arranged so as to face the first interval in the first row of line sensor groups, and the adjacent first line sensor and the second line Adjacent to the sensor A computer-executable program for processing image data generated by the imaging unit having an overlap region where ends overlap in the main scanning direction, and generated by the line sensor group in the first row Of the first image data read from the image memory storing the first image data based on the detected signal and the second image data based on the detection signal generated by the line sensor group of the second row. Selected from the reference data having a predetermined first width in the sub-scanning direction in the overlap region and the second image data read from the image memory in the same overlap region. The process of comparing the comparison data having the same width as the width of 1 is applied to a plurality of positions where the position of the comparison data is moved in the sub-scanning direction. Processing for calculating the similarity between the reference data and the comparison data, the position of the reference data in the sub-scanning direction, and the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data A process of calculating shift amount data based on the difference from the position of the image, and reading out the first image data and the second image data from the image memory, and combining in the sub-scanning direction based on the shift amount data It is characterized by causing a computer to execute processing for combining the first image data and the second image data by changing the position.

An image processing apparatus according to another aspect of the present invention includes at least two line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction at different positions in the sub scanning direction, and adjacent line sensors in different lines. Is an apparatus for processing image data generated by an imaging unit arranged so as to have an overlap region in which the end portions overlap in the main scanning direction, and stores image data based on an output from the line sensor Based on an image memory and a thinning rate set in accordance with a reading magnification in the sub-scanning direction by the line sensor, the image data stored in the image memory is used in a predetermined sub-scanning direction in the overlap region. Read the reference data at the position and the comparison data in the area overlapping the overlap area of the reference data A process of comparing the reference data read by the read control unit and the reference data with the comparison data is performed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data A similarity calculation unit that calculates the similarity between the comparison data for the positions in the plurality of sub-scanning directions, the position in the sub-scanning direction of the reference data, and the comparison data at the positions in the plurality of sub-scanning directions A shift amount estimation unit that calculates shift amount data based on a difference between the comparison data having the highest degree of similarity and a position in the sub scanning direction, and the shift amount data in the sub scanning direction based on the thinning rate. A shift amount enlargement unit that converts the shift amount data into enlarged shift amount data by enlarging and interpolating, and the image memory based on the enlarged shift amount data. Determine the position of the image data read from the image in the sub-scanning direction, read the image data at the determined position from the image memory, and combine the image data read by the adjacent line sensors in different columns And a combination processing unit for generating composite image data.

An image processing method according to another aspect of the present invention includes at least two line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction at different positions in the sub scanning direction, and adjacent line sensors in different lines. A method of processing image data generated by an imaging unit arranged so as to have an overlap region where ends of the image sensor overlap in the main scanning direction, wherein image data based on an output from the line sensor is stored in an image memory And a predetermined sub-level in the overlap region from the image data stored in the image memory based on a storage step stored in the image sensor and a thinning rate set according to a reading magnification in the sub-scanning direction by the line sensor. Reference data at a position in the scanning direction and comparison data in an area overlapping the overlap area of the reference data. Performing a process of comparing the reference data and the comparison data read in the reading step with respect to a plurality of positions in which the position of the comparison data is moved in the sub-scanning direction, A similarity calculation step for calculating a similarity between the reference data and the comparison data for the plurality of sub-scanning direction positions; a position in the sub-scanning direction of the reference data; and a plurality of sub-scanning position positions A shift amount calculating step for calculating shift amount data based on a difference between the comparison data having the highest similarity in the comparison data and a position in the sub-scanning direction, and subtracting the shift amount data based on the thinning rate. A shift amount enlargement step for converting the shift amount data into enlarged shift amount data by enlarging and interpolating in the scanning direction; The position of the image data read from the image memory in the sub-scanning direction is determined based on the enlarged shift amount data, the image data at the determined position is read from the image memory, and the adjacent line sensors in different columns are used. A combination processing step of generating composite image data by combining the read image data.

An image reading apparatus according to another aspect of the present invention has at least two line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction at different positions in the sub scanning direction, and adjacent line sensors in different lines. An image pickup unit arranged so as to have an overlap region in which the end portions overlap in the main scanning direction, an image memory storing image data based on an output from the line sensor, and a sub-scanning direction by the line sensor Based on the thinning rate set in accordance with the reading magnification, from the image data stored in the image memory, reference data at a position in a predetermined sub-scanning direction in the overlap area, and the overrun of the reference data. A read control unit that reads comparison data in a region that overlaps the wrap region, and the read control unit reads The process of comparing the issued reference data and the comparison data is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, and the reference data and the plurality of positions in the sub-scanning direction are compared. A similarity calculation unit for calculating a similarity to the comparison data, a position of the reference data in the sub-scanning direction, and comparison data having the highest similarity among the comparison data at the plurality of sub-scanning positions. A shift amount estimation unit that calculates shift amount data based on a difference from a position in the sub-scanning direction, and the shift amount data is expanded and interpolated in the sub-scanning direction based on the decimation rate. A shift amount enlargement unit for converting the image data into enlargement shift amount data, and a position in the sub-scanning direction of image data read from the image memory based on the enlargement shift amount data A combination processing unit configured to read out the image data at the determined position from the image memory and combine the image data read out by adjacent line sensors in different columns to generate composite image data; It is characterized by providing.

A program according to another aspect of the present invention includes at least two line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction at different positions in the sub-scanning direction, and ends of adjacent line sensors in different columns. A program for causing a computer to execute processing of image data generated by an imaging unit arranged so as to have an overlap region that overlaps each other in the main scanning direction, and an image based on an output from the line sensor From the image data stored in the image memory based on a storage process for storing data in the image memory and a thinning rate set in accordance with a reading magnification in the sub-scanning direction by the line sensor, the overlap region Reference data at a predetermined position in the sub-scanning direction and the overlap region of the reference data A plurality of read control processes for reading comparison data in an overlapping region and a process for comparing the reference data read in the reading step with the comparison data, the positions of the comparison data being moved in the sub-scanning direction A similarity calculation process for calculating a similarity between the reference data and the comparison data for the plurality of sub-scanning direction positions, a position of the reference data in the sub-scanning direction, and the plurality of sub-scanning positions. A shift amount calculation process for calculating shift amount data based on a difference between the comparison data having the highest degree of similarity in the comparison data at a position in the scanning direction and a position in the sub-scanning direction, and based on the decimation rate, By expanding and interpolating the shift amount data in the sub-scanning direction, the shift amount data for converting the shift amount data into enlarged shift amount data is displayed. Determining a position in the sub-scanning direction of image data read from the image memory based on the step and the enlargement shift amount data, reading the image data at the determined position from the image memory, and adjacent to different columns And a combining process for generating composite image data by combining the image data read by the line sensor.

According to one aspect of the present invention, a line belonging to the second row line sensor group is set to a reference position in the sub-scanning direction of the divided image indicated by the image data generated by the line sensor belonging to the first row line sensor group. Since the position in the sub-scanning direction of the divided image indicated by the image data generated by the sensor is shifted and no accumulation of misalignment occurs, high-quality composite image data corresponding to the object to be read can be generated.

According to another aspect of the present invention, there is no need to expand the search range for detecting the amount of positional deviation in the sub-scanning direction between the image data of the line sensors in each column even when the reading magnification is changed. Therefore, it is not necessary to change the contents of the positional deviation amount detection process, and it is not necessary to increase the circuit scale. Furthermore, according to the present invention, even when the reading magnification is changed, the amount of positional deviation can be obtained with high accuracy, so that high-quality composite image data can be generated.

1 is a functional block diagram schematically showing a configuration of an image reading apparatus according to Embodiment 1 of the present invention. (A) is a top view which shows roughly the 1st line | wire line sensor group and the 2nd line | wire line sensor group which comprise the imaging part shown by FIG. 1, (b) is a 1st row | line | column. It is a figure which shows the original as a to-be-read part read by the line sensor group and the line sensor group of the 2nd row. It is a schematic plan view which expands and shows one line sensor shown by Fig.2 (a). (A) to (c) show the state when the document is in close contact with the glass surface, (a) is a schematic side view of the imaging unit, (b) is a schematic plan view of the imaging unit and FIG. 4C is a plan view of a document, and FIG. 5C shows read image data. (A) to (c) show a state where the document is floating from the glass surface, (a) is a schematic side view of the imaging unit, (b) is a schematic plan view of the imaging unit and the document (C) is a figure which shows the read image data. It is a figure for demonstrating the digital data stored in an image memory. It is explanatory drawing which shows operation | movement of a similarity calculation part when a document is closely_contact | adhered to the glass surface. It is explanatory drawing which shows operation | movement of a similarity calculation part when a manuscript floats from the glass surface. (A) And (b) is a figure which shows the operation | movement of a similarity calculation part in detail. It is explanatory drawing which shows an example of operation | movement of a joint process part. It is explanatory drawing which shows the other example of operation | movement of a joint process part. It is a figure which shows the image data which a joint process part outputs. (A) And (b) is a figure which shows the example from which the position of a document changes during conveyance of an imaging part. (A) And (b) is a figure for demonstrating the case where the distance of a manuscript and a glass surface changes to a main scanning direction. It is a functional block diagram which shows roughly the structure of the image reading apparatus and image processing apparatus which concern on Embodiment 2 of this invention. 10 is a flowchart schematically illustrating an example of a processing procedure performed by the arithmetic device according to the second embodiment. (A) And (b) is a side view which shows roughly the structure of the imaging part of the image reader which concerns on Embodiment 3 of this invention. It is a functional block diagram which shows roughly the structure of the image reading apparatus which concerns on Embodiment 4 of this invention. (A) And (b) is a figure for demonstrating the imaging part in Embodiment 4, (a) is the 1st line | wire group of line sensors and 2nd which comprise the imaging part shown by FIG. FIG. 2B is a plan view schematically showing a line sensor group in a row, and FIG. 5B is a view showing a document as a read portion read by the line sensor group in the first row and the line sensor group in the second row. is there. It is a schematic plan view which expands and shows one line sensor shown by Fig.18 (a). (A) to (c) show the state when the document is in close contact with the glass surface, (a) is a schematic side view of the imaging unit, (b) is a schematic plan view of the imaging unit and A plan view of the document, (c) is a diagram conceptually showing image data of the read image. (A) to (c) show a state in which the document is separated from the glass surface, (a) is a schematic side view of the imaging unit, (b) is a schematic plan view of the imaging unit and the document (C) is a diagram conceptually showing image data of a read image. FIG. 10 is a diagram for explaining an operation when a document is in close contact with a glass surface and is read at a variable magnification of 1 (equal magnification) in the read control unit of the fourth embodiment. FIG. 10 is a diagram for explaining an operation when a document is separated from a glass surface and read at a variable magnification of 1 (equal magnification) in the read control unit of the fourth embodiment. FIG. 10 is a diagram for explaining an operation when a document is in close contact with a glass surface and read at a magnification of 4 times, which is an example of a magnification process, in the readout control unit of the fourth embodiment. FIG. 10 is a diagram for explaining an operation when a document is separated from a glass surface and read at a magnification of 4 which is an example of a magnification process in the read control unit of the fourth embodiment. (A) And (b) is a figure which shows the positional relationship of the data for demonstrating operation | movement in the read-out control part of Embodiment 4 in the case of variable magnification 1 time (equal magnification). (A) And (b) is a figure which shows the positional relationship of the data for demonstrating the operation | movement in the read-out control part of Embodiment 4 in the case of the scaling factor 4 times which is an example of a scaling process. (A) is a figure for demonstrating operation | movement of the similarity calculation part of Embodiment 4, (b) is the similarity data (correlation data) calculated in the similarity calculation part, and the position shift of a subscanning direction It is a figure for demonstrating the relationship of quantity. FIG. 15 is a diagram for explaining an operation of calculating enlargement shift amount data when the variable magnification is 1 (equal magnification) in the shift amount enlargement unit of the fourth embodiment. FIG. 18 is an explanatory diagram illustrating an example of an operation of calculating enlargement shift amount data in a case where the shift amount enlargement unit according to the fourth embodiment has a scaling factor of 4 as an example of a scaling process. FIG. 16 is an explanatory diagram illustrating another example of the operation of calculating enlargement shift amount data in the case of the enlargement / reduction rate of 4 times, which is an example of enlargement / reduction processing, in the shift amount enlargement unit of the fourth embodiment. FIG. 20 is an explanatory diagram illustrating an example of a combining operation in a combining processing unit according to the fourth embodiment. (A) And (b) is explanatory drawing which shows the other example of the coupling | bonding operation | movement in the coupling | bonding process part of Embodiment 4. FIG. It is a figure which shows notionally the image data which a joint process part outputs. (A) And (b) is a figure which shows the example from which the position of a document changes during conveyance of an imaging part. It is a functional block diagram which shows schematically the structure of the image reading apparatus which concerns on Embodiment 5 of this invention. FIG. 20 is a diagram for explaining the relationship between the search range of the positional deviation amount in the sub-scanning direction with respect to the similarity data (correlation data) in the shift amount estimation unit of the fifth embodiment. It is a functional block diagram which shows roughly the structure of the image reading apparatus and image processing apparatus which concern on Embodiment 6 of this invention. 22 is a flowchart schematically illustrating an example of a processing procedure performed by the arithmetic device according to the sixth embodiment. (A) And (b) is a side view which shows roughly the structure of the imaging part of the image reader which concerns on Embodiment 7 of this invention. FIG. 20 is a diagram illustrating an example of image data of an image read by an imaging unit according to the seventh embodiment. In Embodiment 7, it is a figure for demonstrating the image data after correct | amending the amount of positional deviation of the fixed amount of subscanning directions.

<< 1 >> Embodiment 1
FIG. 1 is a functional block diagram schematically showing a configuration of an image reading apparatus 1 according to Embodiment 1 of the present invention. As shown in FIG. 1, the image reading apparatus 1 according to the first embodiment includes an imaging unit 2, an A / D conversion unit 3, and an image processing unit 4. The image processing unit 4 is an image processing apparatus according to the first embodiment (an apparatus that can perform the image processing method according to the first embodiment), and includes an image memory 41, a similarity calculation unit 42, and a shift amount. An estimation unit 43 and a combination processing unit 44 are provided.

The image reading apparatus 1 includes a plurality of first line sensors (for example, FIG. 2A) arranged in a line at a first interval (for example, 22 or 23 in FIG. 2A) in the main scanning direction. , The first row of line sensor groups including 21O or 21E), and the first row of line sensor groups arranged at different positions in the sub-scanning direction and having a second interval in the main scanning direction (for example, FIG. ) In the second row sensor group including a plurality of second line sensors (for example, 21E or 21O in FIG. 2A) that are arranged in a line by opening 23 or 22). In the imaging unit 2, a plurality of first line sensors (for example, 21O or 21E in FIG. 2A) belonging to the first row line sensor group are included in the second row line sensor group. The second interval (eg, A plurality of second line sensors (for example, 21E or 21O in FIG. 2A) that are arranged to face 23 or 22) in (a) and belong to the second row line sensor group are the first. An adjacent first line sensor and an adjacent end of the second line sensor are arranged so as to oppose a first interval (for example, 22 or 23 in FIG. 2A) in the line sensor group of the row. The portions (for example, sr, sl in FIG. 2A) overlap each other in the main scanning direction (for example, _{Ak, k,} etc. in FIG. 2A). In addition, the image reading apparatus 1 receives the first image data based on the detection signal generated by the first row line sensor group and the second image data based on the detection signal generated by the second row line sensor group. The image memory 41 to be stored and the reference data having a predetermined first width in the sub-scanning direction in the overlap area in the first image data read from the image memory 41 and the image in the same overlap area The process of comparing the comparison data having the same width as the first width selected from the second image data read from the memory 41 is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction. And a similarity calculation unit 42 for calculating the similarity between the reference data and the comparison data. Further, the image reading apparatus 1 calculates shift amount data based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest similarity among the plurality of comparison data in the sub-scanning direction. The first image data and the second image data are read from the shift amount estimation unit 43 and the image memory 41, and the first image data and the second image data are changed by changing the coupling position in the sub-scanning direction based on the shift amount data. A combination processing unit 44 for combining the image data;

FIG. 2A is a plan view schematically showing the imaging unit 2, and FIG. 2B is a plan view showing a document 60 as an object to be read. FIG. 2A shows, for example, a state in which an original table glass (hereinafter referred to as “glass surface”) 26 of the copying machine is viewed from above. FIG. 3 is a diagram for explaining the configuration of the line sensor using the line sensor 21O ₁ which is one of the components of the imaging unit 2.

As illustrated in FIG. 2A, the imaging unit 2 includes a sensor substrate 20. A plurality of line sensors are arranged in two rows on the sensor substrate 20. In the sensor substrate 20, one end (e.g., left side) line sensor _21O 1 located odd counted _{from, ..., 21O k, ...,} 21O n is spaced 22 in the main scanning direction of the linear are arranged, the line sensor _21E 1 located to the even-numbered from the _{left, ..., 21E k, ...,} 21E n is the line sensor _21O 1 located odd, _..., 21O k, ..., and 21O _n Are arranged at different positions in the main scanning direction (X direction) with a space 23 in a straight line in the main scanning direction. Here, n is an integer of 2 or more, and k is an integer of 1 to n. Line sensor _21O 1 located _{odd, ..., 21O k, ...,} 21O n is the first column line group of sensors comprising a plurality of first line sensor (or first comprises a plurality second line sensor The line sensors 21E ₁ ,..., 21E _k ,..., 21E _n located in the even-numbered line sensors are configured as a second line sensor group (or a plurality of second line sensors) (or 1st line sensor group including a plurality of first line sensors).

As shown in FIG. 2A, a plurality of first line sensors (for example, 21E ₁ ,..., 21E _k ,..., 21E _n ) belonging to the first row line sensor group are replaced with the second row line sensors. A plurality of line sensors (for example, 21O ₁ ,..., 21O _k ,..., 21O that are arranged to face a second interval (for example, 23,. _n ) are arranged to face a first interval (for example, 22,..., 22) in the first row of line sensor groups, and adjacent end portions of the adjacent first line sensor and the second line sensor. There is an overlapping region (overlap region) where the ends (ends sr and sl) overlap in the main scanning direction.

As shown in FIG. 2A, the imaging unit 2 is moved in the sub-scanning direction (Y direction) by the transport unit 24, and reads a document 60 as a read object. Further, the transport unit 24 may be a device that transports the document 60 in a direction opposite to the sub-scanning direction (−Y direction). In each embodiment of the present application, a case where the imaging unit 2 is moved by the transport unit 24 will be described. Incidentally, the sub-scanning direction (Y-direction) indicates the moving direction of the imaging unit 2, the main scanning direction, the line sensor _21O 1 located odd, _..., 21O k, ..., the arranging direction of 21O _n, or, line sensor _21E 1 located even-numbered, showing _..., 21E k, ..., the arranging direction of 21E _n.

As shown in FIG. 3, the line sensor 21O ₁ includes a plurality of red photoelectric conversion elements (R photoelectric conversion elements) 26R that convert red component light of received light into electrical signals, and the received light. A plurality of green photoelectric conversion elements (G photoelectric conversion elements) 26G for converting green component light into electrical signals and a plurality of blue photoelectric conversions for converting blue component light of received light into electrical signals And an element (B photoelectric conversion element) 26B. As shown in FIG. 3, the plurality of R photoelectric conversion elements 26R are linearly arranged in the main scanning direction (X direction), and the plurality of G photoelectric conversion elements 26G are linear in the main scanning direction (X direction). The plurality of B photoelectric conversion elements 26B are arranged linearly in the main scanning direction (X direction). In Embodiment 1, the line sensor having the configuration shown in FIG. 3 will be described. However, the present invention may be configured such that black and white photoelectric conversion elements that do not identify colors are arranged in a line. Further, the arrangement of the plurality of R photoelectric conversion elements 26R, the plurality of G photoelectric conversion elements 26G, and the plurality of B photoelectric conversion elements 26B is not limited to the example of FIG. The line sensor 21O ₁ outputs the received information as an electric signal SI (O ₁ ). The line sensor _{_{_{21E 1, 21O 2, ...,}}} 21O n, 21E n similarly received information an electric signal _{_{SI (E 1), SI (}} O 2), ..., SI (O n), SI (E n ). Electrical signals output from all line sensors are denoted as electrical signal SI. The electrical signal SI output from the imaging unit 2 is input to the A / D conversion unit 3.

Line sensor

_21O 1 located _{odd, ..., 21O k, ...,} 21O n a line sensor _21E 1 located _{even-numbered,} ..., 21E k, ..., A 21E _n, the original 60 and partially overlapping overlap region _a _1,1, _a _1,2 _{reading, ..., a k, k,} a k, K + 1, a k + 1, K + 1, ..., having _{a n, n.} Details of the overlap region will be described later.

The A / D conversion unit 3 converts the electric signal SI output from the imaging unit 2 into digital data DI. The digital data DI is input to the image processing unit 4 and stored in the image memory 41 of the image processing unit 4.

FIGS. 4A to 4C are diagrams for explaining the digital data DI stored in the image memory 41. FIG. 4 (a) is a line sensor _21O 1 located odd, _..., 21O k, ..., the line sensor _21E 1 located to the even-numbered and _{_{21O n, ..., 21E k,}} ..., the optical axis of 21E _n It is a figure which shows the positional relationship of the original document 60 and line sensor in case the original document 60 exists in the crossing position. FIG. 4B is a diagram illustrating an example of the document 60. FIG. 4C is a diagram showing digital data DI corresponding to the document 60 of FIG. 4B when the document 60 and the line sensor are in the positional relationship of FIG.

FIG. 4A is a schematic side view of the image reading apparatus 1 and shows a state where the copying machine is viewed from the side. Line sensor _21O 1 positioned to the odd-numbered as shown in FIG. _{2 (a), ..., 21O} k, ..., 21O n is also the line sensor 21O expressed, the line sensor _21E 1 located even-numbered, ..., 21E _k ,..., 21E _n are also expressed as a line sensor 21E. The reflected light of the document 60 irradiated with the illumination light source 25 such as a light emitting diode (LED) is guided to the line sensor 21O along the optical axis 27O, and is guided to the line sensor 21E along the optical axis 27E. The imaging unit 2 conveyed in the sub-scanning direction (Y direction) sequentially photoelectrically converts the reflected light of the document 60 placed on the glass surface 26 and outputs the converted electric signal SI. The A / D conversion unit 3 The electrical signal SI is converted into digital data DI and output.

When the original 60 as shown in FIG. 4B is sequentially photoelectrically converted by the imaging unit 2 and converted into digital data by the A / D converter 3, the digital data DI as shown in FIG. Stored in the memory 41. Digital data DI, the line sensor _21O 1 located odd, _..., 21O k, ..., the digital data _DI (O 1) generated by _{_{21O n, ..., DI (O}} k), ..., DI (O n) , 21E _k ,..., 21E _{n and} the digital data DI (E ₁ ),..., DI (E _k ),..., DI (E _n ) generated by the even-numbered line sensors 21E ₁ ,. . In FIG. 4C, digital data DI (O _k ) and DI (O _{k + 1} ) generated by odd-numbered line sensors 21O _k and 21O _{k + 1} , and even-numbered

line sensors

21E _k and 21E _{k + 1} are obtained. Digital data DI (E _k ) and DI (E _{k + 1} ) to be generated are shown.

Here, the overlap area _{_{_{_{A 1,1, A 1,2, ...,}}}} A k, k, A k, K + 1, A k + 1, K + 1, ..., A n, n will be described. As shown in FIG. 2 (a), the imaging unit 2 is conveyed in the sub-scanning direction (Y-direction), the line sensor _21O 1 located odd, _..., 21O k, ..., even-numbered and 21O _n line sensor _21E 1 _located, ..., 21E k, ..., reads a subset same region (overlap region) at 21E _n. For example, the left end sl the right sr and the line sensor 21E ₁ of the line sensor 21O ₁ reads the area _{A 1, 1} of the document 60. Similarly, the right end sr of the line sensor 21 E ₁ and the left end sl of the line sensor 21 O ₂ read the areas A ₁ and _{2 of the} document 60.

Referring to the example shown in FIG. 4 (b), the left end sl the right sr and the line sensor 21E _k of the line sensor 21O _k are both read the area _{A k, k} of the original 60, and the right end sr line sensor 21E _k left sl line sensor _{21O k + 1} reads both areas _{a k} of the original _60, a _{k + 1,} the left end sl the right sr and the line sensor _{21E k + 1} of the line sensor _{21O k + 1} are both read the area _{a k + 1, k + 1} of the document 60.

Thus, the digital data DI _{(O k)} corresponding to the line sensor 21O _k includes digital data _{d r} corresponding to the area _{A k, k} of the original 60, the digital data DI corresponding to the line sensor 21E _k _(E _k) _Includes digital data dl corresponding to the areas A _{k, k} of the document 60. When the original 60 is in close contact with the glass surface 26 as shown in FIG. 4A, the reading positions of the line sensor 21O and the line sensor 21E in the sub-scanning direction (Y direction) of the original 60 are it is almost the same position, as shown in FIG. 4 (c), the digital data d _r and d _l adjacent will free data position shift of the sub-scanning direction of the document 60 (Y-direction).

Next, the case where the positional relationship between the original 60 and the line sensor changes from that shown in FIG. FIGS. 5A to 5C are diagrams for explaining the digital data DI stored in the image memory 41. FIG. 5 (a) is a line sensor _21O 1 of document 60 is located in the odd-numbered floats from the glass surface 26, _..., 21O k, ..., the line sensor _21E 1 located to the even-numbered and 21O _n, ..., 21E _k , ..., the position where the optical axis of 21E _n intersect a diagram showing a positional relationship between the document 60 and the line sensor when there is a document 60 in a different position, FIG. 5 (b), an example of a document 60 FIG. 5C is a diagram showing digital data DI corresponding to the document 60 of FIG. 4B when the document 60 and the line sensor are in the positional relationship of FIG. 5A.

Even if the document 60 is lifted off the glass surface 26, the positional relationship between the line sensor and the document 60 when viewed in plan is not changed. That is, data at the same position is acquired in the main scanning direction (X direction). Thus, in FIG. 5 (b), the left sl the right sr and the line sensor 21E _k likewise line sensor 21O _k and FIG. 4 (b), both read the area _{A k, k} of the original 60, the line sensor 21E _k the right sr and the line sensor _{21O k + 1} of the left sl are both reading area _{a k} of the original _60, a _{k + 1,} the line sensor _{21O k + 1} of the rightmost sr and the line sensor _{21E k + 1} of the left sl are both area _{a k + 1} of the original _60, Read _{k + 1} .

On the other hand, FIG. 5 as shown in (a), when viewed in side view of the imaging unit 2, the line sensor _21O 1 document 60 is positioned on an odd-numbered order that floats from the glass surface 26, ..., _21O k, ..., the line sensor _21E 1 to the optical axis 27O of 21O _n is located at the position and the even-numbered intersecting the

document

60, _..., 21E k, ..., a position where the optical axis 27E intersects the document 60 21E _n different. Therefore, when the document 60 is floating from the glass surface 26, the reading position is different in the sub-scanning direction (Y direction). This is because when the imaging unit 2 is transported in the sub-scanning direction (Y direction), each line sensor sequentially performs photoelectric conversion, and therefore, even-numbered line sensors 21E ₁ ,..., 21E _k ,. , 21E _n is the line sensor _21O 1 located odd, _..., 21O k, ..., compared to 21O _n, to obtain an image of the same position temporally delayed. Accordingly, as shown in FIG. 5C, the digital data DI (O _k ) and DI (O _{k + 1} ) corresponding to the even-numbered line sensors 21O _k and 21O _{k + 1} and the odd-numbered line sensor 21E. _The digital data DI (E _k ) and DI (E _{k + 1} ) corresponding to _{k 1} and 21E _{k + 1} are stored in the image memory 41 in a shifted manner.

6 and 7 are diagrams for explaining the operation of the similarity calculation unit 42. Figure 6 is a view corresponding to FIG. 4 (c), it shows the positional relationship between the image data MO and the image data ME at position Y _m in the sub-scanning direction (Y-direction). Figure 7 is a view corresponding to FIG. 5 (c), the shows the positional relationship between the image data MO and the image data ME at position Y _m in the sub-scanning direction (Y-direction). As shown in FIG. 1, the similarity calculation unit 42 generates correlation data D42 based on the image data MO and the image data ME.

Similarity calculation unit 42, the position _Y image data MO _(O k data around the _m sub-scanning direction (Y direction) in the region _{d r} of the line sensor 21O _k into corresponding digital data DI _{(O k),} d _r , Y _m ), and the data around the position Y _m in the sub-scanning direction (Y direction) in the region d _l of the digital data DI (E _k ) corresponding to the line sensor 21E _k is ME (E _k , d _l , Y _m ). The image data (comparison data) ME is set to be wider in the sub-scanning direction (Y direction) than the image data (reference data) MO.

FIGS. 8A and 8B are diagrams for explaining the operation of the similarity calculation unit 42 in more detail. The image data MO (O _k , d _r , Y _m ) and the image data ME (E _k , d _l , Y _m ) are composed of a plurality of pixel data. First, the similarity calculation unit 42 has a plurality of the same size (width in the same sub-scanning direction) as the image data MO (O _k , d _r , Y _m ) from the image data ME (E _k , d _l , Y _m ). Image data ME (E _k , d _l , Y _m , ΔY) is extracted. ΔY is the amount of deviation from the image data MO (O _k , _dr , Y _m ), and takes a value within the range of −y to y. Data having the same center position of the image data MO (O _k , _dr , Y _m ) is taken as image data ME (E _k , d _l , Y _m , 0), and data shifted by one pixel is ME (E _k , d ₁ , Y _m , 1), and further shifted by one pixel, the data shifted by y pixels is image data ME (E _k , d _l , Y _m , y), and the data shifted by y pixels in the reverse direction The image data is ME (E _k , d _l , Y _m , -y).

Next, correlation data between the image data MO (O _k , _dr , Y _m ) and the image data ME (E _k , d _l , Y _m , -y) to ME (E _k , d _l , Y _m , y). D42 (O _k , E _k , Y _m ) is calculated. Each of the image data MO (O _k , d _r , Y _m ) and the image data ME (E _k , d _l , Y _m , -y) to ME (E _k , d _l , Y _m , y) has a size. Are the same, for example, image data MO (O _k , d _r , Y _m ) and image data ME (E _k , d _l , Y _m , -y) to ME (E _k , d _l , Y _m , y) The sum of absolute values of differences for each pixel or the sum of squares of differences for each pixel is calculated and output as correlation data D42 (O _k , E _k , Y _m ). Image data _{_{MO (E k, d r,}} Y m) and the image data _{_{ME (O k + 1, d}} l, Y m), the image data _{_{MO (O k + 1, d}} r, Y m) and the image data ME _{(E k +} 1, d _l, _{Y m)} Similarly correlation data also _{_{_{D42 (E k, O k +}}} 1, Y m), calculates the _{_{D42 (O k + 1, E}} k + 1, Y m).

The shift amount estimation unit 43 outputs the shift amount ΔY corresponding to the data with the highest similarity as the shift amount data D43. In FIG. 8 (b), the correlation data and the dashed line corresponds to the FIG. _{_{6 D42 (O k, E k}} , Y m) is the correlation data solid line corresponds to FIG. _{_{7 D42 (O k, E k}} , Y m) It is. In Figure 6, the line sensor _21O 1 located odd, _..., 21O k, ..., the line sensor _21E 1 located to the even-numbered and _{_{21O n, ..., 21E k,}} ..., 21E n sub-scanning direction (Y-direction ), The same position is read, so the data is not shifted. Accordingly, the degree of similarity is high (that is, the degree of dissimilarity is low) at the position of ΔY = 0 as indicated by the broken line in FIG. Further, in FIG. 7, the line sensor _21O 1 located odd, _..., 21O k, ..., the line sensor _21E 1 located to the even-numbered relative to _{_{21O n, ..., 21E k,}} ..., 21E n of the read image Is shifted upward, the degree of similarity is highest (that is, the degree of dissimilarity is lowest) at the position of the negative value (ΔY = −α).

The combination processing unit 44 performs a process of shifting data based on the shift amount data. FIG. 9 and FIG. 10 are diagrams for explaining the operation of the combination processing unit 44. 9, only the data corresponding to the even-numbered line sensors 21E ₁ ,..., 21E _k ,..., 21E _n may be shifted, or as shown in FIGS. line sensor _21O 1 located _odd, ..., 21O k, ..., data corresponding to 21O _n, a line sensor _21E 1 located _{even-numbered,} ..., 21E k, ..., the both data corresponding to 21E _n The shift amount may be combined and shifted so as to be equivalent to the shift amount data. In FIG. 10 (a), shifting the position _{Y m} in the sub-scanning direction used in the similarity calculation unit 42 (Y-direction), in FIG. 10 (b), further shifted _{Y m} data apart to the position of _{Y m} Yes. For example, the combination processing unit 44 reads out the first image data and the second image data that are adjacent (partially overlap) with each other in the main scanning direction from the image memory 41, and the first image data and the second image data The shift amount indicated by the shift amount data between the image data is divided, and the first shift amount data indicating one of the divided shift amounts and the second shift amount data indicating the other divided shift amount. The position of the first image data in the sub-scanning direction is corrected based on the first shift amount data, and the position of the second image data in the sub-scanning direction is corrected based on the second shift amount data. Correction may be made to combine the first image data and the second image data.

Coupling processor 44, based on the shift amount data D43, and calculates the reading position RP of the image data, reads out the image data M44 corresponding to the reading position, the line sensor _21O 1 located odd, ..., 21O _k , ..., the line sensor _21E 1 located data and even-numbered 21O _n, _..., 21E k, ..., to generate image data D44 by combining where data 21E _n overlap.

Even number similarity calculation unit 42, the line sensor _21O 1 positioned to the odd-numbered relative to the position _{Y m} of a sub-scanning direction (Y-direction), _..., 21O k, ..., based on the image data corresponding to 21O _n line sensor _21E 1 located th, _..., 21E k, ..., and calculates the shifting image data similarity data (correlation data) D42 corresponding to 21E _n, the shift amount estimation unit 43, for its position _{Y m} The shift amount corresponding to the one having the highest degree of similarity (the largest correlation) is calculated as shift amount data D43, and the combination processing unit 44 reads the image data based on the shift amount data D43, and combines the combined image data D44. Output. This is sequentially performed in the sub-scanning direction (Y direction). FIG. 11 is an image obtained by combining the images of FIG. 4C or FIG. Particularly, in the case of FIG. 5 (c), the line sensor _21O 1 located odd, _..., 21O k, ..., the line sensor _21E 1 located to the image data and the even-numbered 21O _n, ..., _21E k, .., 21E _n is shifted in the sub-scanning direction (Y direction), but the same image as the original 60 shown in FIG. 5B can be output.

FIG. 11 is an explanatory diagram conceptually showing the image data D44 after the combination process output from the combination processing unit 44. Line sensor _21O 1 located _odd, ..., 21O k, ..., the line sensor _21E 1 located to the even-numbered and _{_{21O n, ..., 21E k,}} ..., fixes a displacement of 21E _n, is reading overlapping Merged images.

12A and 12B are diagrams illustrating an example in which the position of the document 60 with respect to the glass surface 26 is changed while the imaging unit 2 is being transported. In the position _{Y m} in the sub-scanning direction (Y-direction), the document 60 is floated from the glass surface 26, the position _{Y u,} document 60 is adhered to the glass surface 26. Since the imaging unit 2 sequentially processes the image data at each position in the sub-scanning direction (Y direction), even if the position of the document 60 changes during conveyance, the amount of deviation at that position is calculated. , Can combine images correctly. The line sensor _21O 1 located odd as described in FIG. 6 and FIG. _{7, ..., 21O k, ...} , 21O n a line sensor _21E 1 located even-numbered, _..., 21E k, ..., 21E _{Since the} shift amount is calculated individually for all _n , even if the position of the document 60 relative to the glass surface 26 in the main scanning direction (X direction) is changed, the images can be combined correctly.

FIGS. 13A and 13B are diagrams for explaining a case where the distance between the document 60 and the glass surface 26 changes according to the position in the main scanning direction. In the example of FIG. 13 (a), the the region F1 including the overlapping area of the line sensor 21O _k and 21E _k, the original 60 is floated from the glass surface 26 (gap G1 has a positive value) is, the line sensor 21E _{In the} region F3 including the overlapping region of _k and 21O _{k + 1 and} the overlapping region of the line sensors 21O _{k + 1} and 21E _{k + 1} , the document 60 and the glass surface 26 are in close contact (the value of the gap G3 is 0). Therefore, in the example of FIG. 13A, the shift amount (interval G2) gradually changes in the digital data DI (E _k ) generated by the line sensor 21E _k that reads the portion corresponding to the area F2 of the document 60. To do. In this case, as shown in FIG. 13B, the combined position of the image data gradually changes in the sub-scanning direction according to the position in the main scanning direction (main scanning position). As described above, even when the position of the document 60 with respect to the glass surface 26 gradually changes according to the position in the main scanning direction, the combining processing unit is configured to combine the first image data and the second image data. By changing the position of the first image data in the sub-scanning direction and the position of the second image data in the sub-scanning direction according to the position in the main scanning direction, the images can be combined correctly.

As described above, according to the image reading device 1, the image processing device 4, and the image processing method according to the first embodiment, the division indicated by the image data generated by the line sensors belonging to the first row of line sensor groups. Using the position in the sub-scanning direction of the image as the reference position (reference data in FIG. 8A), the position in the sub-scanning direction of the divided image indicated by the image data generated by the line sensors belonging to the second row of line sensor groups is shifted. In addition, since there is no accumulation of misalignment, high-quality composite image data corresponding to the object to be read can be generated.

<< 2 >> Embodiment 2
A part of the functions of the image reading apparatus may be realized by a hardware configuration, or may be realized by a computer program executed by a microprocessor including a CPU (central processing unit). When a part of the function is realized by a computer program, the microprocessor loads and executes the computer program from a computer-readable storage medium or by communication such as the Internet. Part can be realized.

FIG. 14 is a functional block diagram showing a configuration when a part of the functions of the image reading apparatus 1a is realized by a computer program. As illustrated in FIG. 14, the image reading device 1 a according to the second embodiment includes an imaging unit 2, an A / D conversion unit 3, and an arithmetic device 5. The arithmetic device 5 includes a processor 51 including a CPU, a RAM (random access memory) 52, a nonvolatile memory 53, a large-capacity storage medium 54, and a bus 55. As the non-volatile memory 53, for example, a flash memory can be used. Further, as the large-capacity storage medium 54, for example, a hard disk (magnetic disk), an optical disk, or a semiconductor storage device can be used.

The A / D conversion unit 3 has the same function as the A / D conversion unit 3 in FIG. 1, converts the electrical signal SI output from the imaging unit 2 into digital data, and stores the digital data in the RAM 52 via the processor 51. .

The processor 51 can realize the function of the image processing unit 4 by loading and executing a computer program from the nonvolatile memory 53 or the mass storage medium 54.

FIG. 15 is a flowchart schematically showing an example of processing by the arithmetic device 5 according to the second embodiment. As shown in FIG. 15, the processor 51 first executes similarity calculation processing (step S1). Thereafter, the processor 51 executes a shift amount estimation process (step S2). Finally, the processor 51 executes a combination process (step S3). Note that the processing in steps S1 to S3 by the arithmetic device 5 is the same as the processing performed by the image processing unit 4 in the first embodiment.

According to the image reading apparatus 1a according to the second embodiment, even if the position of the document 60 is changed during conveyance of the imaging unit 2, the amount of deviation at the position is calculated, so that the images can be combined correctly. .

<< 3 >> Embodiment 3
In the first embodiment, FIG. 4 as (a), the one end (e.g., the left end) line sensor _21O 1 located odd counted from, _..., 21O k, ..., of 21O _n line sensor _21E 1 located to the even-numbered and the optical axis _{27O, ..., 21E k, ...} , and the optical axis 27E of 21E _n has been described a case where intersecting. In the third embodiment, one end (e.g., the left end) line sensor _21O 1 located odd counted from, _..., 21O k, ..., the line sensor located even-numbered and the optical axis 28O of 21O _n A case _where the optical axes 28E of 21E ₁ ,..., 21E _k ,. The image reading apparatus according to the third embodiment is substantially the same as the image reading apparatus 1 according to the first embodiment except that the optical axes 28O and 28E are parallel. Therefore, FIG. 1 is also referred to in the description of the third embodiment.

Figure 16 (a) and (b) is a line sensor _21O 1 positioned to the odd-numbered image pickup section 2 of the image reading apparatus according to the third embodiment, _..., 21O k, ..., the optical axis 28O and even 21O _n line sensor _21E 1, located th _..., 21E k, ..., if the optical axis 28E of 21E _n are parallel, schematic side view showing the positional relationship between the document 60 and the line sensor as the read object It is. FIG. 16A shows a case where the document 60 is in close contact with the glass surface 26 which is the document table mounting surface, and FIG. 16B shows a case where the document 60 is slightly lifted away from the glass surface 26. Indicates.

In the image reading apparatus according to the third embodiment, when the document 60 is in close contact with the glass surface 26 as shown in FIG. 16A, the document 60 is glass as shown in FIG. be any of the cases that floats from the surface 26, the line sensor _21O 1 located odd, _..., 21O k, ..., the read image of the document 60 by 21O _n hardly changes, similarly, the even-numbered line sensor _21E 1 _located, ..., 21E k, ..., the read image of the document 60 by 21E _n is hardly changed. Therefore, the image processing unit 4, the line sensor _21O 1 located odd, _..., 21O k, ..., the image reading by 21O _n, or line sensor _21E 1 located even-numbered, ..., 21E _k, ... , 21E _n, a process of shifting one or both of the scanned images by a substantially constant amount in the sub-scanning direction is performed.

According to the image reading apparatus according to the third embodiment, at the time of imaging by the imaging unit 2, time is taken for the conveyance speed by the conveyance machine when moving either one or both of the document 60 and the imaging unit 2 in the sub-scanning direction. Even when there is a natural fluctuation (that is, speed fluctuation), as in the case of the first embodiment, it is possible to generate combined image data by correctly combining images.

<< 4 >> Embodiment 4
<4-1> Configuration of Embodiment 4 <4-1-1> Image Reading Device 101
FIG. 17 is a functional block diagram schematically showing the configuration of the image reading apparatus 101 according to the fourth embodiment of the present invention. As illustrated in FIG. 17, the image reading apparatus 101 according to the fourth embodiment performs operations of the imaging unit 102, the A / D conversion unit 103, the image processing unit 104, the imaging unit 102, and the image processing unit 104. And a controller 107 to be controlled. The image processing unit 104 is an image processing apparatus according to the fourth embodiment (an apparatus capable of performing the image processing method according to the fourth embodiment), and includes an image memory 141, a read control unit 142, and similarity calculation. Unit 143, shift amount estimation unit 144, shift amount enlargement unit 145, and combination processing unit 146.

The imaging unit 102 has a first row of line sensor groups including a plurality of (for example, n) first row line sensors arranged in a line at intervals in the main scanning direction, and an interval in the main scanning direction. And a second row line sensor group including a plurality of (for example, n) second row line sensors arranged in a line. Here, n is a positive integer. The positions of the plurality of first row line sensors in the main scanning direction are regions where the plurality of second row line sensors are not provided (that is, regions between the second row line sensors adjacent in the main scanning direction). It is a position facing. The positions of the plurality of second row line sensors in the main scanning direction are regions where the plurality of first row line sensors are not provided (that is, regions between the first row line sensors adjacent in the main scanning direction). It is a position facing. As a result, the plurality of first row line sensors and the plurality of second row line sensors are arranged in a staggered pattern on the sensor substrate. Further, among the plurality of first row line sensors and the plurality of second row line sensors, the first row line sensor and the second row line sensor which are adjacent to each other are adjacent to each other in the main scanning. They are arranged so as to have overlapping areas (hereinafter referred to as “overlap areas”) overlapping in the direction. The imaging unit 102 optically reads an image of a document as an object to be read and generates an electrical signal (image data) SI corresponding to the image of the document. The electrical signal (image data) SI generated by the imaging unit 102 includes first image data output from a plurality of first row line sensors constituting the first row line sensor group, and second row lines. And second image data output from a plurality of second line sensors constituting the sensor group. Note that, for example, an erect image is formed on each of the first row line sensor group and the second row line sensor group between the first row line sensor group and the second row line sensor group and the original. An optical system such as a lens may be provided. In the following description, an example in which the imaging unit 102 includes two lines of line sensor groups will be described. However, the present invention can also be applied when the number of lines in the line sensor group is three or more. In addition, the present invention can be applied to a case where an image of an object to be read is read by an imaging unit having two or more line sensors having an overlap region. Therefore, the present invention can also be applied to the case where the first row line sensor group is composed of one line sensor and the second row line sensor group is composed of one line sensor.

The A / D conversion unit 103 converts the electrical signal (image data) SI output from the imaging unit 102 into digital data (image data) DI. The image data DI is input to the image processing unit 104 and stored in the image memory 141 in the image processing unit 104.

Image data DI stored in the image memory 141 in the image processing unit 104 includes first image data based on image data output from a plurality of first-line line sensors constituting the first-line line sensor group, and Second image data based on image data output from a plurality of second line sensors constituting the second row of line sensor groups.

Based on the thinning rate M set in accordance with the scaling ratio R, the read control unit 142 in the image processing unit 104 determines from the image data DI stored in the image memory 141 among the image data in the overlap region. Reference data (for example, reference data MO (O in FIG. 26B and FIG. 27B described later) of a position in a predetermined sub-scanning direction (also referred to as “predetermined sub-scanning position” or “predetermined line”). _k , dr)) and comparison data (for example, comparison data in FIG. 26B and FIG. 27B described later) of a predetermined number of lines in the same overlap region read in duplicate with the reference data. ME (E _k , dl)) is read out.

The similarity calculation unit 143 in the image processing unit 104 performs a process of comparing the reference data and the comparison data for the same overlap region read by the read control unit 142 with a plurality of positions obtained from the comparison data. By performing the above, the similarity in the overlap region between the reference data and the comparison data at a plurality of positions in the sub-scanning direction (that is, the comparison data of a plurality of lines) is calculated. In other words, the similarity calculation unit 143 calculates the similarity (that is, the plurality of similarities corresponding to the plurality of comparison data) for each of the plurality of lines of comparison data with respect to the reference data.

The shift amount estimation unit 144 in the image processing unit 104 is similar to the position of the reference data in the sub-scanning direction based on the comparison data having the highest similarity among the plurality of similarities calculated by the similarity calculation unit 143. The shift amount data d _sh corresponding to the difference between the highest degree comparison data and the position in the sub-scanning direction is calculated.

The shift amount enlargement unit 145 in the image processing unit 104 performs processing (interpolation processing) for enlarging the shift amount data d _sh based on the thinning rate M, thereby _converting the shift amount data d _sh into the enlarged shift amount data. to convert to Δy _b.

The combination processing unit 146 in the image processing unit 104 changes the position in the sub-scanning direction of the image data read from the image memory 141 based on the enlargement shift amount data Δy _b , that is, read from the image memory 141. First image data (image data corresponding to an image read by the first row of line sensor groups) and second image data (image data corresponding to an image read by the second row of line sensor groups) The first image data and the second image data are combined with each other after the positional deviation in the sub-scanning direction is eliminated.

The controller 107 controls the operations of the imaging unit 102 and the image processing unit 104. For example, the controller 107 sends the input setting information such as the scaling ratio R or instruction information to the imaging unit 102 and the image processing unit 104, thereby controlling the reading operation by the imaging unit 102 and the image processing by the image processing unit 104. Control. When zooming processing is performed by the image reading apparatus 101, when a scaling factor is designated by the controller 107 in the image reading apparatus 101, the controller 107 sends setting information for setting the reading scaling factor (scaling factor) R to the imaging unit 102. The instruction information such as the thinning rate M set based on the transmission and variable magnification is sent to the image processing unit 104. As a result, the imaging unit 102 reads the document at a variable magnification other than the equal magnification (that is, a variable magnification of 1), and image data (image signal) of the number of lines expanded or reduced in the sub-scanning direction according to the variable magnification. Is generated and output.

Here, the thinning rate M set in the controller 107 in the image reading apparatus 101 is set to an integer value of 1 or more close to a variable magnification R that is a reading magnification, for example. For example, when the variable magnification R is 2 times (R = 2), the thinning rate M is set to 2, and when the variable magnification R is 4 times (R = 4), the thinning rate M is set to 4. Further, for example, when the variable magnification R is 0.8 times (R = 0.8), the thinning rate M is set to 1, and the variable magnification R is 1.5 times (R which is an intermediate magnification between 1 time and 2 times). = 1.5), the thinning rate M is set to 2. Thus, the thinning rate M is set to an integer value equal to the scaling factor R or an integer value closest to the scaling factor R, for example. Note that the method of setting the thinning rate M corresponding to the scaling factor R is not limited to the above example. Accordingly, in the image processing unit 104, it is necessary to perform the thinning process in the read control unit 142 and the enlargement process in the shift amount enlargement unit 145 by complicated processing such as enlargement or reduction processing by a filter operation such as line interpolation. However, it can be performed by simplified processing such as line thinning for every integer line or double writing interpolation (repeated insertion) and averaging processing, and there is no need to increase the circuit scale of the image processing unit 104.

<< 4-1-2 >> Imaging Unit 102
18A and 18B are diagrams for explaining the imaging unit 102. FIG. 18A is a plan view schematically showing the imaging unit 102, and FIG. 18B is a plan view showing a document 160 as an object to be read. FIG. 18A shows, for example, a state in which an original table (hereinafter referred to as “original table glass” or “glass surface”) 126 of a copying machine on which an original as an object to be read is placed is viewed from above. Figure 19 is a diagram for explaining the structure of one of a plurality of line sensors provided in the imaging unit 102 (illustrated line sensors 121 o _1). Note that the document table 126 may have another structure as long as it is limited to the glass surface and can determine the position of the document 160 at a predetermined position.

As illustrated in FIG. 18A, the imaging unit 102 includes a sensor substrate 120. Two rows of line sensor groups including a first row line sensor group and a second row line sensor group are arranged on the sensor substrate 120. In the sensor substrate 120, one end (e.g., left side) the line sensor 121 o ₁ located odd counted _{from, ..., 121O k, ...,} 121O n , the spacing in a straight line in the main scanning direction (X-direction) Is opened and placed. In the sensor substrate 120, the line sensor 121E ₁ located to the even-numbered counting from the same _{end, ..., 121E k, ...,} 121E n is the line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O _n are arranged at different positions in the main scanning direction at intervals in a straight line in the main scanning direction so as to partially face each other and form a staggered pattern. Here, n is an integer of 2 or more, and k is an integer of 1 to n. Line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O n is the first column line group of sensors including a line sensor of a plurality of the first column (or a line sensor of a plurality of the second column Line sensors 121E ₁ ,..., 121E _k ,..., 121E _n are included in the second row line sensors including a plurality of second row line sensors. A group (or a first row line sensor group including a plurality of first row line sensors) is formed.

As shown in FIG. 18A, a plurality of first row line sensors (eg, 121E ₁ ,..., 121E _k ,..., 121E _n ) belonging to the first row line sensor group The line sensors are arranged so as to face regions between line sensors adjacent to each other in the main scanning direction. A plurality of line sensors belonging to the second column line group of sensors _{_{(e.g., 121O 1, ..., 121O k}} , ..., 121O n) during the line sensors adjacent to each other the main scanning direction in the first column line group of sensors It arrange | positions so that it may oppose the area | region of. Further, adjacent (closest) end portions (end portions sr and sl) of the adjacent first row line sensor and second row line sensor have overlapping regions (overlap regions) overlapping in the main scanning direction. is doing.

As shown in FIG. 18A, the imaging unit 102 is moved in the sub-scanning direction (Y direction) by the transport unit 124 (for example, shown in FIG. 20A), and the document 160 as a reading object. Read. The imaging unit 102 may be a device that reads the document 160 by fixing the imaging unit 102, transporting the document 160 in the direction opposite to the sub-scanning direction (−Y direction) by the transport unit 124. Here, in each embodiment of the present application, a case will be described in which the imaging unit 102 is moved in the direction of the arrow Dy (for example, shown in FIG. 18A) by the transport unit 124. The sub-scanning direction (Y direction) indicates the moving direction of the imaging unit 102 (the arrow Dy direction in FIG. 18A), and the main scanning direction is an odd-numbered line sensor 121O ₁ ,..., 121O _k. , ..., the arranging direction of 121 o _n, or line sensor 121E ₁ located even-numbered, _..., shown 121E k, ..., the arranging direction of 121E _n.

When performing the scaling process in the image reading apparatus 101, when the magnification ratio is designated by the user or the like in the controller 107, setting information for setting the scanning magnification, that is, the magnification ratio R is sent to the imaging unit 102. For example, the magnification of the imaging unit 102 is changed by changing the speed of the imaging unit 102 that is moved by the transport unit 124 to 1 / R when the magnification is 1 × while the reading period of the line sensor is constant. . Note that scaling processing can also be performed by fixing the imaging unit 102 and changing the speed at which the document 160 is conveyed to 1 / R when the scaling ratio is 1.

As shown in FIG. 19, the line sensor 121O ₁ includes a plurality of red photoelectric conversion elements (R photoelectric conversion elements) 126R that convert red component light of received light into an electrical signal, and the received light. A plurality of green photoelectric conversion elements (G photoelectric conversion elements) 126G for converting green component light into electrical signals, and a plurality of blue photoelectric conversions for converting blue component light of received light into electrical signals Element (B photoelectric conversion element) 126B. As shown in FIG. 19, the plurality of R photoelectric conversion elements 126R are linearly arranged in the main scanning direction (X direction), and the plurality of G photoelectric conversion elements 126G are linear in the main scanning direction (X direction). The plurality of B photoelectric conversion elements 126B are arranged linearly in the main scanning direction (X direction). In the fourth embodiment, the line sensor having the configuration shown in FIG. 19 will be described. However, the present invention is a line sensor in which monochrome photoelectric conversion elements that do not identify colors are arranged in a line in the main scanning direction (X direction). The present invention is also applicable to an image reading apparatus provided with Further, the arrangement of the plurality of R photoelectric conversion elements 126R, the plurality of G photoelectric conversion elements 126G, and the plurality of B photoelectric conversion elements 126B is not limited to the arrangement shown in FIG. 19, and other arrangement methods may be adopted. Good. The line sensor 121O ₁ outputs the received information as an electric signal SI (O ₁ ). Similarly, the line sensors 121E ₁ , 121O ₂ ,..., 121O _n , 121E _n also receive the received light signals as electrical signals SI (E ₁ ), SI (O ₂ ),..., SI (O _n ), SI. Output as (E _n ). When the entire electric signals SI (E ₁ ), SI (O ₂ ),..., SI (O _n ), SI (E _n ) are shown, the electric signals (image data) output from the respective line sensors are converted into SI. Also written. The electrical signal SI output from the imaging unit 102 is input to the A / D conversion unit 103.

Line sensor 121 o ₁ located odd, _..., 121O k, _..., the line sensor 121E ₁ located to the even-numbered and _{_{121O n, ..., 121E k,}} ..., and 121E _n, direction main scan ends of each other Is partially duplicated. That is, the line sensor _{_{121O 1, ..., 121O k,}} ..., 121O n and the line sensor _{_{121E 1, ..., 121E k,}} ..., and 121E _n, the

overlap area

_A 1, 1 for reading an original _{160, A 1, 2} _{_{, ..., a k, k,}} a k, K + 1, a k + 1, K + 1, ..., has _{a n,} a _n. Details of the overlap area will be described later.

The electrical signal SI input to the A / D conversion unit 103 is converted into digital data (image data) DI and stored in the image memory 141 of the image processing unit 104.

<< 4-1-3 >> Image Processing Unit 104
20A to 20C are views for explaining the image data DI stored in the image memory 141 in the image processing unit 104. FIG. 20 (a) is the line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O n and the line sensor 121E ₁ located even-numbered, _..., 121E k, ..., the optical axis 127O of 121E _n And the optical axis 127E intersect with each other (that is, when the optical axes 127O and 127E intersect on the glass surface 126 when the optical axes 127O and 127E are viewed in the Y direction). FIG. 6 is a diagram showing a positional relationship between the original 160 and a line sensor. FIG. 20B is a diagram illustrating an example of the document 160. FIG. 20C conceptually shows image data DI corresponding to the document 160 of FIG. 20B read when the document 160 and the line sensor are in the positional relationship of FIG. .

FIG. 20A is a schematic side view of the image reading apparatus 101 and shows a state in which an apparatus (for example, a copying machine) including the image reading apparatus 101 is viewed from the side. Line sensor 121 o ₁ positioned to the odd-numbered as shown in Figure _{18 (a), ..., 121O} k, ..., 121O n is also the line sensor 121 o expressed, the line sensor 121E ₁ located even-numbered, ..., 121E _k ,..., 121E _n are also referred to as line sensors 121E. Reflected light from the original 160 irradiated with light from an illumination light source 125 such as a light emitting diode (LED) enters the line sensor 121O along the optical axis 127O, and enters the line sensor 121E along the optical axis 127E. The imaging unit 102 conveyed in the sub-scanning direction (Y direction) sequentially photoelectrically converts the reflected light of the document 160 placed on the glass surface 126 and outputs the converted electric signal SI. The A / D conversion unit 103 The electric signal SI is converted into image data DI and output. The direction of the optical axis 127O, the line sensor _{_{121O 1, ..., 121O k,}} ..., can be set to a desired direction by way of the installation of the 121 o _n, the direction of the optical axis 127E, the line sensor 121E _1, ..., 121E _k, ..., can be set to a desired direction by way of the installation of the 121E _n. The direction of the optical axis 127O, the line sensor _{_{121O 1, ..., 121O k,}} ..., can also be configured by an optical system such as a lens disposed between the 121 o _n and the glass surface 126, the optical axis 127E direction, the line sensor _{_{121E 1, ..., 121E k,}} ..., may be set by the optical system such as a lens disposed between the 121E _n and the glass surface 126.

When an original 160 as shown in FIG. 20B is sequentially photoelectrically converted by the imaging unit 102, and the electric signal SI generated as a result is converted into image data DI by the A / D converter 103, FIG. ) Is stored in the image memory 141. Image data DI, the line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O n thus generated image data _{_{DI (O 1), ...,}} DI (O k), ..., DI (O n a), the line sensor 121E ₁ located _{even-numbered, ..., 121E k, ...,} 121E n thus generated image data _{_{DI (E 1), ...,}} DI (E k), ..., and DI _{(E n)} Consists of. FIG. 20C shows image data DI (O _k ) and DI (O _{k + 1} ) generated by the odd-numbered line sensors 121O _k and 121O _{k + 1} and the even-numbered

line sensors

121E _k and 121E _{k + 1.} The image data DI (E _k ) and DI (E _{k + 1} ) generated by the above are shown.

Here, the overlap area _{_{_{_{A 1,1, A 1,2, ...,}}}} A k, k, A k, k + 1, A k + 1, K + 1, ..., A n, n will be described. As shown in FIG. 18A, when the imaging unit 102 reads the document 160 while moving in the sub-scanning direction (Y direction), the odd-numbered line sensors 121O ₁ ,..., 121O _k ,. and the region on the document _{160 n} reads, the line sensor 121E ₁ located even-numbered, _..., 121E k, ..., a region on the document 160 to be read by the 121E _n is a portion overlapping region (overlapping region) Become. For example, the right end (end portion) of the line sensor 121 o ₁ Both the sr and left (end) of the line sensor 121E ₁ sl, reads the overlap area _{A 1, 1} of the document 160. Similarly, any and left sl the right sr and the line sensor 121 o ₂ of the line sensor 121E _1, reads the overlap area _{A 1, 2} of the document 160.

In the example shown in FIG. 20B, the right end sr of the line sensor 121O _k and the left end sl of the line sensor 121E _k both read the overlap areas A _{k and k} of the original 160, and the line sensor 121E _k the right end sr and the line sensor 121 o _{k + 1} of the left sl, both read overlap area _{a k} of the original _160, a _{k + 1,} the line sensor 121 o _{k + 1} of the rightmost sr and the line sensor 121E _{k + 1} of the left sl, both over the original 160 The wrap areas A _{k + 1 and k + 1} are read.

Thus, image data DI _{(O k)} corresponding to the line sensor 121 o _k is the overlap area _{A k} of the document _160, includes a digital data _{d r} corresponding to _k, image data DI (E corresponding to the line sensors 121E _k _k ) includes digital data d ₁ corresponding to the overlap areas A _{k, k} of the original 160. When the original 160 is in close contact with the glass surface 126 as shown in FIG. 20A, the reading positions of the line sensor 121O and the line sensor 121E in the sub-scanning direction (Y direction) of the original 160 are is almost the same position, as shown in FIG. 20 (c), the digital data d _r and d _l adjacent will free data position shift of the sub-scanning direction of the original 160 (Y-direction).

Next, a case will be described in which the positional relationship between the original 160 and the line sensor is different from the case shown in FIG. FIGS. 21A to 21C are diagrams for explaining the image data DI stored in the image memory 141. FIG. FIG. 21 (a), original document 160 are floated from the glass surface 126, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., the line sensor 121E ₁ positioned to the optical axis and the even-numbered 121 o _n , _..., 121E k, ..., in a case where the optical axis of 121E _n is the document 160 in a different position than the position that intersects a diagram showing the positional relationship between the document 160 and the line sensor. FIG. 21B is a diagram illustrating an example of the document 160. FIG. 21C illustrates the document 160 illustrated in FIG. 21B when the document 160 and the line sensor are in the positional relationship illustrated in FIG. It is a figure which shows notionally the image data DI corresponding to.

Even when the document 160 is lifted off the glass surface 126, the positional relationship between the line sensor and the document 160 when viewed in plan is not changed. That is, the image data acquired by reading the image of the original 160 in which each line sensor is in close contact with the glass surface 126 and the image of the original 160 at which each line sensor is lifted from the glass surface 126 are acquired. The image data to be processed is the same data in the main scanning direction (X direction). Accordingly, in FIG. 21B, as in the case of FIG. 20B, the right end sr of the line sensor 121O _k and the left end sl of the line sensor 121E _k are both overlap regions A _{k, k.} read, and the right end sr and the line sensor 121 o _{k + 1} of the left sl of the line sensor 121E _k, both the overlap area _{a k} of the original _160, reads a _{k + 1,} the line sensor 121 o _{k + 1} of the rightmost sr and the line sensor 121E _{k + 1} of the left sl Both read the overlap areas A _{k + 1, k + 1} of the original 160.

On the other hand, as shown in FIG. 21 (a), when viewed in side view of the imaging unit 102, since the document 160 is floated from the glass surface 126, the line sensor 121 o ₁ located odd, ..., 121 o _k , ..., the line sensor 121E ₁ of the optical axis 127O of 121 o _n is located at the position and the even-numbered intersecting the

document

160, _..., 121E k, ..., and a position where the optical axis 127E intersects the original 160 121E _n different. Therefore, when the document 160 is floating from the glass surface 126, the reading position in the sub-scanning direction (Y direction) is different. That is, the image data obtained by reading the image of the original 160 in which each line sensor is in close contact with the glass surface 126 and the image of the original 160 in which each line sensor is lifted from the glass surface 126 are obtained. The image data to be processed is different data in the sub-scanning direction (Y direction). This is because when the imaging unit 102 is transported in the sub-scanning direction (Y direction), each line sensor sequentially performs photoelectric conversion, and therefore, even-numbered line sensors 121E ₁ ,..., 121E _k ,. , 121E _n is the line sensor 121 o ₁ located odd, _..., 121 o k, ..., compared to 121 o _n, because the obtaining the image data of the image in the same position temporally delayed. Accordingly, as shown in FIG. 21C, the image data DI (O _k ) and DI (O _{k + 1} ) corresponding to the even-numbered line sensors 121O _k and 121O _{k + 1} and the odd-numbered line sensor 121E. _The image data DI (E _k ) and DI (E _{k + 1} ) corresponding to _{k 1} and 121E _{k + 1} are stored in the image memory 141 with their positions in the sub-scanning direction shifted. That is, the position of the image data DI (O _k ) and DI (O _{k + 1} ) corresponding to the even-numbered line sensors 121O _k and 121O _{k + 1} and the odd-numbered

line sensors

121E _k and 121E _{k + 1.} Are different positions (different lines) from the positions of the image data DI (E _k ) and DI (E _{k + 1} ) in the sub-scanning direction.

Here, the image data DI stored in the image memory 141 when performing the scaling process will be described. In both cases where the original 160 is in close contact with the glass surface 126 (see FIG. 20A) and away from the glass surface 126 (see FIG. 21A), the magnification R is changed. When the document 160 is read by the image pickup unit 102, the number of lines read in the sub-scanning direction is enlarged or reduced at the magnification of the variable magnification R in the sub-scanning direction, with the reference when the variable magnification R is 1 (R = 1). The image data DI is stored in the image memory 141. For example, when the magnification ratio R is 4 (R = 4), the number of lines in the sub-scanning direction of the image data DI corresponding to the document 160 shown in FIGS. 20C and 21C is the magnification ratio. The image is stored in the image memory 141 as an image having four times the number of lines when R is one. When the variable magnification R is smaller than 1 (R = 1) (for example, when R = 0.8), the read image is reduced, and the number of lines in the sub-scanning direction is 0. The image multiplied by 8 is stored in the image memory 141.

That is, for a normal scaling factor (equal magnification), that is, a distance between a certain line Y _m when R = 1 and a line Y _m +1 one line below (referred to as one line or one line interval). During the scaling process, that is, when R ≠ 1, the distance between the lines Y _m and the line Y _m +1 on the original 160 obtained by reading the same position is enlarged or reduced by the scaling factor R. Number of lines. Therefore, when the document 160 is in close contact with the glass surface 126, digital data _{d r} and _{d l} adjacent shown in FIG. 20 (c), no positional deviation of the sub-scanning direction of the document 160 (i.e., The amount of misalignment is 0), and the data is also free from misalignment in the sub-scanning direction during the scaling process. On the other hand, when the document 160 is separated from the glass surface 126, the image data DI (O _k ), DI (O _{k + 1} ) and the image data DI (E _k ), DI (E _{k + 1} ) shown in FIG. Is read with the position in the sub-scanning direction of the document 160 shifted, so that during the scaling process, the digital data _dr and _dl have the value of the scaling ratio R as the positional shift amount when the scaling ratio is 1. The multiplied value is stored in the image memory 141 as data having a positional deviation.

The image processing unit 104 reads the image data in the overlap region from the image memory 141 based on the thinning rate M set according to the scaling ratio R, compares the reference data with a plurality of comparison data, and compares a plurality of similarities. The shift amount data d _sh is calculated using the position in the sub-scanning direction of the comparison data from which the highest similarity among the calculated similarities is obtained. Further, the image processing unit 104 uses the thinning rate M, by performing the processing for enlarging the shift amount data d _sh in the sub-scanning direction, to generate an enlarged shift amount data [Delta] y _b, the expansion shift quantity data [Delta] y _b The image data at the position in the sub-scanning direction is read from the image memory 141, and the image data combining process is executed. Hereinafter, the processing of the image processing unit 104 will be specifically described.

The read control unit 142 in the image processing unit 104 receives a thinning rate M set according to the scaling factor R from the controller 107. Based on the thinning rate M (for example, every M line interval indicated by the thinning rate M) of the image data in the overlap region in the image memory 141, that is, the image data DI, the read control unit 142 is a predetermined amount. position Y _m and the image data around the sub-scanning direction (Y direction) (for example, by cross-hatching of each read reference line Y _m and M line intervals indicated in FIG. 26 to be described later (a) and FIG. 27 (a) The indicated line) is read out as reference data rMO. The read control unit 142 includes a reference data RMO to duplicate the same overlapping area is read, within a predetermined range before and after the line of position Y _m in the sub-scanning direction of the reference data RMO (Y-direction) position and the image data of the periphery thereof (e.g., FIG. 26 to be described later (a) and a line indicated by hatching for each read reference line Y _m and M line intervals indicated in FIG. 27 (a)) compare data rME Read as. The read control unit 142 outputs reference data MO and comparison data ME having a predetermined number of lines. Predetermined range is a range from -y around the reference line _{Y m} to + y, that is, the search range "-y ~ + y". Here, y is a value having a unit of a predetermined number of lines at a variable magnification R = 1. The + y direction is the sub-scanning direction (Y direction), and the -y direction is the opposite direction to the + y direction.

The predetermined search range “−y to + y” is described as a difference from the center line position of the reference data rMO, that is, a positional deviation amount (also referred to as “shift amount”, which is referred to as a positional deviation amount ΔYa or a positional deviation amount ΔY. .) Search range. The predetermined search range “−y to + y” is the distance or optical axis between the original 160 and the glass surface 126 when the original 160 is read by the imaging unit 102 of the image reading apparatus 101 by the same magnification processing (R = 1). It is determined in consideration of the amount of position shift in the sub-scanning direction that may occur due to a shift between 127O and the optical axis 127E. The predetermined search range “−y to + y” is a search range for detecting a position (line) in the sub-scanning direction in which image data is shifted in the combination processing, that is, a position shift amount in the sub-scanning direction. The deviation amount ΔY takes a value within a predetermined search range “−y to + y”. Here, the positional deviation amount (difference between the center position of the reference data and the line position) at the time of reading from the image memory 141 is defined as a positional deviation amount ΔYa, and the positional deviation amount at the time of output from the readout control unit 142 is the positional deviation amount ΔY. Represent as The positional deviation amount ΔYa is within a range of M times the number of lines by the thinning rate M that changes with the scaling factor R, that is, within a search range from − (M × y) to + (M × y) with the reference line as the center. Value. This search range is also expressed as “− (M × y) to + (M × y)”. The positional deviation amount ΔY when output from the read control unit 142 is always a value within the positional deviation search range “−y to + y”.

When the thinning rate M is 1 and the magnification ratio R is equal to 1, the readout control unit 142 performs the same magnification processing or the reduction magnification processing in which the magnification ratio R is smaller than 1, and the read control unit 142 sets one line based on the thinning rate M. At each interval (that is, at a normal line interval), the line Y _m in the overlap region in the image memory 141 and the data rMO that is the peripheral image data are output as read reference data MO, and the corresponding other overlap region Is a data within the search range “−y to + y” with the line Y _m as the center, that is, data in the range from the line (Y _m −y) to (Y _m + y) and the surrounding image data. rME is read and output as comparison data ME. In this way, in the equal magnification process, the read control unit 142 outputs the reference data MO and the comparison data ME of the lines in the search range “−y to + y” with the line Y _m as the center. Possible range of the displacement amount ΔY becomes a search range for detecting a sub-scanning direction positional shift amount, the reference data MO and the line Y _m centered search range "-y ~ + y" comparison data ME in Is sent to the similarity calculator 143.

Read control unit 142, when performing scaling processing for the decimation rate M on the basis of the thinning rate M, at each M-line interval, the image data rMO in the overlap region of image memory 141 near the line Y _m Is output as reference data MO, and the corresponding overlap region is within the search range “− (M × y) to + (M × y)” centered on the line Y _m , that is, the line (Y _m - reading the image data rME per M lines in the range of (M × y)) to _{(Y m + (M × y} )), and outputs the comparison data ME. The positional deviation amount ΔYa at the time of reading is a line within the search range “− (M × y) to + (M × y)” with the line Y _m as the center. The search range “− (M × y) to + (M × y)” centered on the line Y _m is a range of M times the number of lines based on the thinning rate M. However, the read control unit 142 reads in the M line interval by thinning rate M (i.e., reading one line for each M line) since the image data output from the read control unit 142, with a focus on lines Y _m Search The line is within the range of the number of lines within the range “−y to + y”. As described above, in the scaling process, the read control unit 142 outputs the reference data MO and the comparison data ME of the lines in the search range “−y to + y” with the line Y _m as the center. Possible range of the displacement amount ΔY becomes a search range for detecting a sub-scanning direction positional shift amount, the reference data MO and the line Y _m centered search range "-y ~ + y" comparison data ME in Is sent to the similarity calculator 143.

As described above, the read control unit 142 reads the data for each M line interval as the reference data rMO from the image data rMO stored in the image memory 141 using the thinning rate M, and outputs it as the reference data MO. Then, from the image data rME stored in the image memory 141, data at intervals of M lines, and the positional deviation amount ΔYa within the search range “− (M × y) to + (M × y)” , Read out as comparison data rME and output as comparison data ME. For this reason, in the read control unit 142, the misregistration amount ΔYa at the time of reading includes a line number range of M times using the thinning rate M in order to include a line range changed by the scaling factor R. Become. However, the search range for detecting the amount of positional deviation in the sub-scanning direction when outputting from the read control unit 142 is that the positional deviation amount ΔY is 1 within the search range “−y to + y” centered on the line Y _m. It is possible to output the reference data MO that is not changed by the scaling factor and the comparison data ME of the lines in the search range “−y to + y” in a line unit range. Therefore, the line corresponding to the range in the sub-scanning direction can be accurately searched without the need to increase the circuit scale such as increasing the line memory to expand the search range for the misalignment amount. Image data can be obtained.

<< 4-2 >> Operation of Embodiment 4 << 4-2-1 >> Operation of Read Control Unit 142 In FIGS. 22 to 25, the read control unit 142 uses the thinning rate M to read the reference data rMO from the image memory 141. It is a figure for demonstrating the operation | movement which reads comparison data rME.

22 and 23 show the case of the equal magnification process (R = 1), and FIGS. 24 and 25 show the case of the scaling process (for example, R = 4). In the case of R = 4, one line interval in the case of R = 1 is four times the four line interval. FIG. 22 is a diagram corresponding to FIG. 20C (when the original 160 is in close contact with the glass surface 126), and in the same magnification processing, a position Y _m (line Y _m ) in the sub-scanning direction (Y direction). ) Shows the positional relationship between the image data rMO read out as reference data and the image data rME read out as comparison data. The image data rME read out as the comparison data has the positional deviation amount ΔYa within the search range “−y to + y” centered on the line Y _m , that is, from the line (Y _m −y) to the line (Y _m + y). ) Image data within the range up to. FIG. 23 is a diagram corresponding to FIG. 21C (when the document 160 is separated from the glass surface 126), and in the same magnification processing, the position Y _m (line Y _m ) in the sub-scanning direction (Y direction). The positional deviation amount ΔYa read as the reference data and the image data rMO read out as the reference data in FIG. 4 indicate the positional relationship between the image data rME within the search range “−y to + y” with the line Y _m as the center.

Similarly, FIG. 24 is a diagram corresponding to FIG. 20C (when the document 160 is in close contact with the glass surface 126), and in the scaling process (R = 4), the sub-scanning direction (Y direction). The positional relationship between the image data rMO read out as reference data and the image data rME read out as comparison data at the position Y _m4 (the reading position of the original 160 corresponding to the line Y _m in FIG. 22) is shown. The image data rME read out as comparison data has a positional deviation amount ΔYa within the search range “−4y to + 4y” centered on the line Y _m4 , that is, from the line (Y _m4 −4y) to the line (Y _m4 + 4y). ) Image data within the range up to. FIG. 25 is a diagram corresponding to FIG. 21C (when the document is separated from the glass surface 126), and in the scaling process (R = 4), a position Y _m4 (Y direction) in the sub-scanning direction (Y direction). The positional relationship between the image data rMO read out as reference data and the positional deviation amount ΔYa read out as comparison data in the search range “−4y to + 4y” at the reading position of the original 160 corresponding to the line Y _m in FIG. Is shown.

As described with reference to FIG. 17, the read control unit 142 reads the data rMO stored in the image memory 141 based on the thinning rate M, outputs the reference data MO, and is stored in the image memory 141. The read data rME is read and the comparison data ME is output. For equal-magnification processing shown in FIGS. 22 and 23 (R = 1), the read control unit 142, in the overlap region _{d r} of the image data DI corresponding to the line sensor 121O _{_k (O} _k), 1 line Peripheral image data centered on the line Y _m is read as reference data rMO (O _k , d _r , Y _m ) for each interval, and the overlap region d of the image data DI (E _k ) corresponding to the line sensor 121E _k is read. _{In l} , the line in the search range “−y to + y” centered on the line Y _m and the surrounding image data are read out as comparison data rME (E _k , d _l , Y _m ). As the comparison data rME (E _k , d _l , Y _m ), the read control unit 142 reads the image data of the lines in the search range “−y to + y” with the line Y _m as the center. Image data (comparison data) rME becomes wider in the sub-scanning direction (Y direction) than reference data) rMO. In FIGS. 22 and 23, the read control unit 142, the overlap region _{d l} of the image data DI overlap region _{(O k)} _{d r} and the image data DI _{(E k),} the reference data RMO _(O k, Similar to the case of reading out d _r , Y _m ) and comparison data rME (E _k , d _l , Y _m ), the overlap region d _{l of} the image data DI (O _{k + 1} ) and the image data DI (E _k ) are sequentially read. The reference data rMO (O _{k + 1} , d ₁ , Y _m ) and the comparison data rME (E _k , d _r , Y _m ) are read from the overlap area d _{r of} the image data DI (O _{k + 1} ). from the overlap region _{d l} of the _r and the image data DI _{(E k + 1),} the reference data _{_{rMO (O k + 1, d}} r, Y m) and the comparison data _{_{rME (E k + 1, d}} l , Y _m ).

In the case of the scaling process (R = 4) shown in FIG. 24 and FIG. 25, the read control unit 142 stores the image data DI (O _k ) corresponding to the line sensor 121O _k based on the thinning rate M = 4. in the overlap region _{d r,} the image data of the surrounding around the line _{Y m4} every four line interval reference data _{_{_{rMO (O k, d r,}}} Y m4) read as image data DI corresponding to the line sensors 121E _k In the overlap region d _l of (E _k ), the lines at intervals of 4 lines in the search range “−4y to + 4y” centered on the line Y _m4 and the surrounding image data are compared with the comparison data rME (E _k , d _l , Y _m4 ). Since the readout control unit 142 reads out the image data of the lines at intervals of 4 lines within the search range “−4y to + 4y” with the line Y _m4 as the center, the image data (comparison data) is compared with the image data (reference data) rMO. Data) rME becomes wider in the sub-scanning direction (Y direction). Also in FIGS. 24 and 25, the overlap region _{d l} of the image data DI overlap region _{(O k)} _{d r} and the image data DI _{(E k),} the reference data _{_{_{rMO (O k, d r,}}} Y m4) And the comparison data rME (E _k , d _l , Y _m4 ), the read control unit 142 sequentially reads the overlap region d _{l of} the image data DI (O _{k + 1} ) and the image data DI (E _k ). The reference data rMO (O _{k + 1} , d ₁ , Y _m4 ) and the comparison data rME (E _k , d _r , Y _m4 ) are read out from the overlap area d _{r of} the image data DI (O _{k + 1} ). from the overlap region _{d l} of the _r and the image data DI _{(E k + 1),} the reference data _{_{rMO (O k + 1, d}} r, Y m4) and comparison data RME _{(E k + 1} , d _l , Y _m4 ). At the time of reading, as for the comparison data rME, the positional deviation amount ΔYa is read from the range within the search range “−4y to + 4y”, but since the reading control unit 142 reads out every four lines by the thinning rate M, the comparison data rME The number of lines at is equal to the number of lines in the range of one line unit within the search range “−y to + y” where the positional deviation amount ΔY is.

FIGS. 26A and 26B and FIGS. 27A and 27B are diagrams for explaining the operation of the read control unit 142 in more detail. FIGS. 26A and 26B show the case of the equal magnification process (R = 1), and FIGS. 27A and 27B show an example of the scaling process (R = 4). In the overlap region _{d l} of the overlap region _{d r} and the image data DI of the image data DI _{(O k)} _{(E k),} the reference data rMO for the line _{Y m} and _{Y m4} (read reference line) (Fig. 26 (a) In FIG. 27 (a), lines indicated by grid-like shading (cross-hatching) and the amount of displacement ΔYa (within the search range “−y to + y” in FIG. 26 (a) and the search in FIG. 27 (a)). The positional relationship of the lines for reading the comparison data rME (within the range “−4y to + 4y”) (the lines indicated by diagonal lines (hatched hatched parallel lines) in FIGS. 26A and 27A) The positional relationship between the reference data MO and the comparison data ME in the sub-scanning direction (line direction) when output from the read control unit 142 is shown. As shown in FIG. 26A and FIG. 27A, the read control unit 142 uses the line Y _m and the line Y _m4 as reference lines, respectively, and the reference data rMO and comparison data for each M line with the thinning rate M. Read rME. The reference data rMO and the comparison data rME are usually composed of data of a plurality of pixels in the main scanning direction and the sub scanning direction. Further, as shown in FIGS. 26B and 27B, the reference data MO and the comparison data ME output from the read control unit 142 are in the main scanning direction and the sub data centering on the detection reference line Y0. It consists of data of a plurality of pixels in the scanning direction.

First, the case of the same magnification processing (R = 1) shown in FIGS. 26A and 26B will be described. For equal magnification processing (R = 1), the

read control unit

142, 1 per line interval, the reference line _{Y m} based on the image data in the sub-scanning direction width bh lines around the data RMO _(O k, d _r , Y _m ) (line indicated by grid-like shading in FIG. 26A), and in the overlap region d _l of the image data DI (E _k ), a search centered on the reference line Y _m Image data rME (E _k , d _l , Y _m , ΔYa) such that each line in the range “−y to + y” has a bh line having the same width as rMO (O _k , d _r , Y _m ). Is read out as comparison data rME (E _k , d ₁ , Y _m ) (a line indicated by hatching in FIG. 26A). At this time, the positional deviation amount ΔYa is a positional deviation amount at the time of reading the reference data rMO (O _k , d _r , Y _m ) and the comparison data rME (E _k , d _l , Y _m ), and the search range “− The value of the interval between one line in y to + y ″ is taken. In FIG. 26A, the data having the same center position as the reference line Y _m is set as image data rME (E _k , d _l , Y _m , 0), 1 The data at the position shifted by the line interval is rME (E _k , d _l , Y _m , 1), and is further shifted by one line interval, and the data shifted at the y line interval is converted into image data rME (E _k , d _l , Y _m , + Y), and the data shifted by the y-line interval in the opposite direction is the image data rME (E _k , d ₁ , Y _m , −y). The read control unit 142 compares the image data rME (E _k , d _l , Y _m , -y) to rME (E _k , d _l , Y _m , + y) with the comparison data rME (E _k , d _l , Y _m ). Here, the 1-line interval is a value indicating the width in the sub-scanning direction of an image of one line read by the line sensor, and the M-line interval (M is a positive integer) is determined by the line sensor. This is a value indicating the width in the sub-scanning direction of the sequentially read M-line image by the number of lines arranged in the sub-scanning direction.

Then, the read control unit 142 uses the reference data rMO (O _k , d _r , Y _m ) and the comparison data rME (E _k , d _l , Y _m ) as reference data MO (O _k , d _r ) and comparison data ME (E _k , d _l ) for output. Here, the reference data MO _(O k, _{d r)} around the detection reference line Y0 and comparison data ME _(E k, _{d l)} and arranged to output as the reference data _MO (O _{k, d} r) And the comparison data ME (E _k , d _l ) together with information indicating the positional relationship in the sub-scanning direction. Since the read comparison data rME (E _k , d _l , Y _m ) is the image data for each line centering on the line within the search range “−y to + y”, the positional deviation amount ΔYa is read control. In the comparison data ME (E _k , d _l ) output from the unit 142, the search range of the positional deviation amount ΔY is the image data ME (E _k , d _l , each line) within the search range “−y to + y”. Corresponding to (ΔY), the image data rME (E _k , d _l , Y _m , ΔYa) in the read comparison data rME (E _k , d _l , Y _m ) is arranged as it is, and the reference data MO and the search are performed. It is output as comparison data ME for the number of lines in the range “−y to + y”. Specifically, in FIGS. 26A and 26B, the read control unit 142 uses the image data rME (E _k , d _l , Y _m , 0) as data having the same center position as the detection reference line Y0. ME (E _k , d _l , 0) is used, and data rME (E _k , d _l , Y _m , 1) at the position shifted by one line interval is ME (E _k , d _l , 1) and y line interval is shifted. The data rME (E _k , d _l , Y _m , + y) is changed to ME (E _k , d _l , + y), and the data rME (E _k , d _l , Y _m , −y) shifted by the y line interval in the reverse direction. ) As ME (E _k , d _l , -y) and output.

In the case of the scaling process (R = 4) shown in FIGS. 27A and 27B, the read control unit 142 sets the reference line Y _m4 for every four line intervals based on the thinning rate M = 4. Image data of a width bh line (at intervals of 4 lines in the 4 × bh line) centered in the sub-scanning direction is used as reference data rMO (O _k , d _r , Y _m4 ) (in FIG. 27A, a grid network In the overlap region d _l of the image data DI (E _k ), each of the four lines in the search range “−4y to + 4y” around the reference line Y _m4 Image data rME (E _k , d _l , Y _m4 , ΔYa) such that is a width bh line at the same 4-line interval as the reference data rMO (O _k , d _r , Y _m4 ) is compared with the comparison data rME (E _k , d _l, _{Y m} ) In (FIG. 27 (a), the read out as a line) indicated by oblique lines shaded. The positional deviation amount ΔYa is a positional deviation amount when the reference data rMO (O _k , d _r , Y _m4 ) and the comparison data rME (E _k , d _l , Y _m4 ) are read, and the search range “−4y to + 4y”. The value of the interval between the four lines is taken. In FIG. 27A, data having the same center position as the reference line Y _m4 is image data rME (E _k , d _l , Y _m4 , 0), and data at a position shifted by four line intervals is rME (E _k , d ₁ , Y _m4 , 4), and further shifted by 4 line intervals, the data shifted by 4y line intervals is set as image data rME (E _k , d _l , Y _m4 , 4y), and the data shifted by 4y line intervals in the reverse direction. Is image data rME (E _k , d _l , Y _m4 , −4y). The read control unit 142 converts the image data at the 4-line interval from the image data rME (E _k , d _l , Y _m4 , −4y) to rME (E _k , d _l , Y _m4 , 4y) into the comparison data rME ( E _k , d _l , Y _m4 ).

Then, the read control unit 142 uses the reference data rMO (O _k , d _r , Y _m4 ) and the comparison data rME (E _k , d _l , Y _m4 ) as reference data MO (O _k , d _r ) and comparison data ME (E _k , d _l ) for output. The read control unit 142 reads out the image data of the width bh line in the sub-scanning direction every 4 lines in the 4 × bh line from the reference data rMO (O _k , d _r , Y _m4 ). The image data becomes image data having the same number of lines as the reference data MO (O _k , _dr ) that is the output from the read control unit 142 in FIG. Further, the read comparison data rME (E _k , d _l , Y _m4 ) is read out every four lines by the thinning rate M = 4, although the positional deviation amount ΔYa is read from within the search range “−4y to + 4y”. This is image data for every four lines centering on the line of the positional deviation amount ΔYa within the search range “−4y to + 4y”. Therefore, the comparison data ME (E _k , d _l ) output from the read control unit 142 is the image data ME (E _k , d _l , ΔY) of the positional deviation amount ΔY within the search range “−y to + y”. Can be replaced with the image data rME (E _k , d _l , Y _m4 , ΔYa) in the read comparison data rME (E _k , d _l , Y _m4 ), the reference data MO and the search range “−y”. Is output as comparison data ME of the lines in .about. + Y ". Specifically, in FIG. 27B, the read control unit 142 converts the image data rME (E _k , d _l , Y _m4 , 0) to ME (E _k , D _l , 0), and the data rME (E _k , d _l , Y _m4 , 4) at positions shifted by 4 line intervals are ME (E _k , d _l , 1) shifted by 1 line intervals, and 4y line intervals The shifted data rME (E _k , d _l , Y _m4 , 4y) is _defined as ME (E _k , d _l , + y), and the data rME (E _k , d _l , Y _m , − 4y) is replaced with ME (E _k , d _l , −y) and output.

From the above, at the time of reading, the comparison data rME is read from within the search range “−4y to + 4y” of the positional deviation amount ΔYa, but is read every four lines with the thinning rate M, so the positional deviation amount in the comparative data rME. The line of ΔY can be the same as the line in the unit of one line within the search range “−y to + y”. Further, since the thinning rate M is set as an integer equal to or greater than 1 which is close to the scaling factor R which is the reading magnification, a scaling factor smaller than 1 (for example, scaling factor R = 0.8) or a fractional number to the scaling factor Even in the case of an intermediate magnification having a part (for example, R = 1.5 times), image data can be read out by thinning out at a line interval corresponding to the thinning rate M, and enlarged by a filter operation such as line interpolation, There is no need to perform reduction processing, and reading can be performed with processing with a small circuit scale.

In the description of FIGS. 26A and 26B and FIGS. 27A and 27B, the read control unit 142 reads the center of the image data in the overlap area from the image memory 141. And the surrounding image data are read out with a width bh line in the sub-scanning direction at every M line interval at every thinning rate M (every M line interval in the M × bh line), but the width bh is only one line. (That is, only the center line). By taking the width bh in the sub-scanning direction, reference data and comparison data having information on peripheral image data can be obtained, and the similarity can be calculated more accurately by processing in the similarity calculation unit 143 described later. Can do.

Here, in FIGS. 22 to 27 (a) and 27 (b), a case has been described in which the read control unit 142 reads out image data at intervals of M lines based on the thinning rate M. However, the read control unit 142 may read the image data in units of M lines at the thinning rate M, and use the data averaged in units of M lines as reference data rMO and comparison data rME. In this case, since averaging is performed in units of M lines, the positional deviation amount ΔYa at the time of reading is within the search range “− (M × y) to + (M × y)”. The positional deviation amount ΔY at the time of outputting can be a line in the range of one line unit within the search range “−y to + y”. For example, as a method of averaging in units of M lines, while resetting the values in units of M lines, calculating the average value of the adjacent lines and the average value of the next line and the previous line, one line at a time There is a method of executing an average process. According to this method, the averaging process can be performed efficiently. Further, if the averaging process is performed in units of M lines, the image data between the M lines can be used. Therefore, the reference data MO (O _k , _dr ) having more accurate peripheral image data information can be used. And the comparison data ME (E _k , d _l ), and the similarity can be calculated more accurately by the processing in the similarity calculation unit 143.

<4-2-2> Operation of Similarity Calculation Unit 143 The similarity calculation unit 143 in the image processing unit 104 includes a search range “−y˜ + y” for the reference data MO and the positional deviation amount ΔY from the read control unit 142. The comparison data ME by the line in “is sent. The similarity calculation unit 143 performs a process of comparing the reference data MO and the comparison data ME for a plurality of positions within the search range “−y to + y” of the positional deviation amount ΔY, and calculates the correlation data D142 that is the similarity. And generate.

FIGS. 28A and 28B are diagrams for explaining the operation of the similarity calculation unit 143. In FIGS. 28A and 28B, reference data MO (O _k , d _r ) and comparison data ME (E _k , d _l ) centered on the detection reference line Y0 are input to the similarity calculation unit 143. Shows the case. As shown in FIG. 28A, the similarity calculation unit 143 first searches for the positional deviation amount ΔY with the detection reference line Y0 as the center with respect to the input reference data MO (O _k , _dr ). A plurality of pieces of image data having the same size (width bh line in the same sub-scanning direction) as the reference data MO (O _k , d _r ) from the comparison data ME (E _k , d _l ) within the range “−y to + y” Extract ME (E _k , d _l , ΔY). The positional deviation amount ΔY is the positional deviation amount in the sub-scanning direction from the reference data MO (O _k , d _r ) for the comparison data ME (E _k , d _l ), and is within the search range “−y to + y”. Takes the value of Data at the same position as the detection reference line Y0, which is the center position of the reference data MO (O _k , d _r ), is set as image data ME (E _k , d _l , 0), and one line interval in the positive direction of the sub-scanning direction The shifted data is _defined as ME (E _k , d _l , 1), and further shifted by one line interval in the positive direction of the sub-scanning direction, and the data shifted by the y line interval is converted to image data ME (E _k , d _l , + y). ). Further, data obtained by shifting the data shifted by one line in the negative direction of the sub-scanning direction by y lines in the reverse direction is referred to as image data ME (E _k , d _l , -y).

Next, the similarity calculation unit 143 performs image data ME (E _k , d _l , -y) to ME (E _k ) in the reference data MO (O _k , d _r ) and the comparison data ME (E _k , d _l ). , D _l , + y) is calculated as correlation data D142 (O _k , E _k ). Since the reference data MO (O _k , d _r ) and the image data ME (E _k , d _l , −y) to ME (E _k , d _l , + y) have the same size, the similarity calculation unit 143 Is, for example, the sum of absolute values of differences for each pixel of the reference data MO (O _k , d _r ) and the image data ME (E _k , d _l , -y) to ME (E _k , d _l , + y), Alternatively, the sum of squares of differences for each pixel is calculated as the similarity, and is output as correlation data D142 (O _k , E _k , ΔY). Similarly, the similarity calculation unit 143 includes the next reference data MO (O _{k + 1} , d _l ) and comparison data ME (E _k , _dr ), the reference data MO (O _{k + 1} , _dr ) and the comparison data ME (E _{k + 1} , d _l ),... are sequentially calculated, and correlation data D 142 (O _{k + 1} , E _k , ΔY), D 142 (O _{k + 1} , E _{k + 1} , ΔY),.

The search range of the positional deviation amount ΔY between the reference data MO and the comparison data ME is the search range “−y to + y”, and the number of lines of the image data is not changed by the scaling factor R. Therefore, the similarity calculation unit 143 Therefore, it is not necessary to calculate the degree of similarity for detecting the amount of misalignment and to change the number of correlation data D142 to be generated, and the circuit scale is not changed according to the scaling factor.

In FIG. 28 (a), the similarity calculation unit 143 shifts the image from the comparison data ME (E _k , d _l ) within the search range “−y to + y” by one line interval as the positional shift amount ΔY. data _{_{ME (E k, d l,}} ΔY) was to calculate the take similarity (correlation data D142), the similarity calculation unit 143, by interpolation processing from the image data before and after the line, between the line and the line It is also possible to obtain the position in the sub-scanning direction (denoted as sub-line), calculate the similarity to the reference data MO, and generate the correlation data D142.

FIG. 28B shows image data ME (E _k ) in reference data MO (O _k , d _r ) and comparison data ME (E _k , d _l ) centered on the detection reference line Y0 in the similarity calculation unit 143. , D _l , −y) to ME (E _k , d _l , + y) when calculating the degree of similarity ΔY (within the search range “−y to + y”) correlation data D142 (O _k , E An example of the value of _k , ΔY) is shown. In FIG. 28 (b), the curve indicated by the broken line is the correlation data D142 (O _k , E _k , ΔY) corresponding to FIGS. 22 and 24, and the curve indicated by the solid line is shown in FIGS. Corresponding correlation data D142 (O _k , E _k , ΔY). In FIG. 22 and FIG. 24, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., the line sensor 121E ₁ located to the even-numbered and _{_{121O n, ..., 121E k,}} ..., 121E n sub scanning Since the same position is read in the direction (Y direction), the data is not shifted in the sub-scanning direction. Therefore, the degree of similarity is high (that is, the degree of dissimilarity is low) at the position of ΔY = 0 as shown by the broken line in FIG. Further, in FIGS. 23 and 25, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., the line sensor 121E ₁ located to the even-numbered relative _{_{121O n, ..., 121E k,}} ..., 121E _Since the read image of _n is away from the glass surface 126, the similarity is the highest (ie, the dissimilarity is the lowest) at the position of the negative value (ΔY = −α). Even when the scaling process is performed, the range of the positional deviation amount ΔY read from the image memory 141 for each M lines by the thinning rate M from the read control unit 142 is a line within the search range “−y to + y”. Since the reference data MO (O _k , d _r ) and the comparison data ME (E _k , d _l ) are input as shown in FIG. ), The correlation data D142 (O _k , E _k , ΔY) has the same positional deviation amount ΔY calculated by the number of lines in the search range “−y to + y”, and the number of correlation data D142 generated. Alternatively, the processing is not changed according to the scaling factor.

<< 4-2-3 >> Operation of Shift Amount Estimator 144 The shift amount estimator 144 receives, from the similarity calculator 143, correlation data D142 for the positional deviation amounts ΔY of a plurality of lines within the search range “−y to + y”. Receive. The shift amount estimation unit 144 outputs the shift amount ΔY corresponding to the data with the highest similarity among the correlation data D142 of the plurality of lines as the shift amount data d _sh to the shift amount enlargement unit 145.

That is, in FIG. 28B, when the degree of similarity is high (that is, the degree of dissimilarity is low) at the position of ΔY = 0 as in the curve indicated by the broken line, ΔY = 0 is used as the shift amount data d _sh. Further, when the similarity is the highest (ie, the dissimilarity is the lowest) at the position of ΔY = −α as shown by a solid line, ΔY = −α is set as the shift amount data d _sh .

<< 4-2-4 >> Operation of Shift Amount Enlargement Unit 145 The shift amount enlargement unit 145 in the image processing unit 104 receives the thinning rate M set based on the variable magnification from the controller 107, and receives the shift amount data d _sh . Received from the shift amount estimation unit 144. The shift amount enlargement unit 145 is based on the thinning rate M with respect to the shift amount data d _sh from the shift amount estimation unit 144 obtained at the position Y _m (or Y _m4 ) in the sub-scanning direction (Y direction). The value of the shift amount data d _sh is multiplied by M and expanded as (M × d _sh ), and for example, between the line intervals indicated by the thinning rate M (for example, between the line Y _m and the line Y _m + M) The data (M × d _sh ), which is the shift amount data d _sh multiplied by M, is repeatedly inserted to be interpolated (enlarged) in the sub-scanning direction, converted into enlarged shift amount data Δy _b and output.

In other words, the shift amount enlargement unit 145 performs the shift amount data d from the shift amount estimation unit 144 when performing scaling processing with a scaling factor R = 1 or a scaling factor smaller than 1 at which the thinning rate M = 1. _sh is input every M = 1 line interval (at a normal line interval), and is obtained as a positional deviation amount without line thinning within the search range “−y to + y”. The shift amount data d _sh input for each line Y _m is output as enlarged shift amount data Δy _b as it is. When the shift amount enlargement unit 145 performs a scaling process with a thinning rate M (M ≧ 2), the shift amount data d _sh is input every M line intervals, and the search range “− (M × y) ˜ Since + (M × y) ”is a value obtained by thinning out the M line interval (1 / M line value), the shift amount data d _sh is multiplied by M from the thinning rate M ( M × d _sh ), and the shift amount data expanded to (M × d _sh ) is repeatedly inserted between M line intervals (for example, between lines Y _m and Y _m + M) and expanded in the sub-scanning direction. interpolated for converts and outputs the enlarged shift quantity data [Delta] y _b. The enlarged and interpolated enlargement shift amount data Δy _b becomes a positional shift amount in the sub-scanning direction in each line for combining the image data, and this enlargement shift amount data Δy _b is sent to the combination processing unit 146.

Shift amount enlargement unit 145, a thinning rate M, while expanding the value of the shift amount data _{d sh} by M times as _{(M × d sh), (} M × d sh) and the shift amount data M line spacing Therefore, the enlargement shift amount data Δy _b is obtained as a value indicating the amount of misalignment corresponding to the line range changed by the variable magnification R, and is simply enlarged. In processing, shift amount data corresponding to the value in the sub-scanning direction according to the magnification is accurately obtained without the need to increase the circuit scale such as increasing the line memory for expanding the search range of the positional deviation amount. be able to. In the description of the shift amount enlargement unit 145 described above, the value of the shift amount data d _sh is multiplied by M to (M × d _sh ), and then repeatedly inserted during the M line interval and interpolated in the sub-scanning direction. Although the shift amount data d _sh is repeatedly inserted during the M line interval and interpolated and enlarged in the sub-scanning direction, the value of the shift amount data d _sh is multiplied by M and enlarged as (M × d _sh ). , And may be converted into enlarged shift amount data Δy _b , and the same effect as the shift amount enlargement unit 145 described above can be obtained.

29 and FIG. 30, the value of the shift amount data d _sh is multiplied by M based on the decimation rate M in the shift amount enlarging unit 145 and expanded as (M × d _sh ), and the line indicated by the decimation rate M It is a figure for demonstrating the operation | movement which inserts repeatedly during an interval and expands and interpolates shift amount data _dsh .

FIG. 29 shows the case of the same magnification processing (R = 1), and FIG. 30 shows the case of the magnification processing (for example, one line at the time of the same magnification processing with R = 4 is 4 times four lines). FIG. 29 shows the value of the enlarged shift amount data Δy _b converted from the shift amount data d _sh for each position Y _m (horizontal axis) in the sub-scanning direction in the same magnification process ( It is a diagram showing the vertical axis), and shows the case where the shift amount data d _sh is directly converted into the enlarged shift amount data Δy _b for each line and output. FIG. 30 shows the conversion from the shift amount data d _sh to the position Y _m4 (horizontal axis, lines Y _m4 −4, Y _m4 , Y _m4 +4...) In each sub-scanning direction in the scaling process at R = 4. FIG. 7 is a diagram showing the value (vertical axis) of the enlarged shift amount data Δy _b that has been obtained, and the shift amount data d _sh is a value (1 / Therefore, the value of the shift amount data d _sh is multiplied by 4 and expanded as (4 × d _sh ) from the thinning rate M = 4, and the interval between 4 lines (for example, line) (Between Y _m4 and line Y _m4 +4) and (4 × d _sh ) are repeatedly inserted, interpolated in the sub-scanning direction, converted into enlarged shift amount data Δy _b , and output. Yes. Note that the black circles in FIG. 30 indicate the expanded shift amount data (4 × d _sh ) for the lines from which the shift amount data d _sh input at every four line intervals is obtained.

Therefore, the shift amount data d _sh is a value (a value obtained by 1/4 line) obtained by thinning out the positional deviation amount at every four line intervals. from rate M = 4, to expand the value of the shift amount data d _sh as (4 × d _sh), interpolated by repeatedly inserting and was the shift quantity data in the sub-scanning direction (4 × d _sh), expanded Since it is converted into the shift amount data Δy _b , the enlarged shift amount data Δy _b can be obtained as a value indicating a positional shift amount corresponding to a four-fold line range after being subjected to the scaling process at the scaling ratio R. Further, since the thinning rate M is set as an integer equal to or greater than 1 which is close to the scaling factor R which is the reading magnification, a scaling factor smaller than 1 (for example, scaling factor R = 0.8) or a fractional number to the scaling factor Even in the case of an intermediate magnification having a part (for example, R = 1.5), an interpolation process for expanding the value of the shift amount data d _sh and repeatedly inserting it in the sub-scanning direction according to the thinning rate M is an integer. The image can be enlarged by a simple operation of doubling, and it is not necessary to perform an interpolation process by a filter operation such as line interpolation using several lines, and can be converted into the enlarged shift amount data Δy _b by a process with a small circuit scale. it can.

In the shift amount enlargement unit 145 in FIG. 30, the case has been described in which the shift amount data is repeatedly inserted and interpolated in the sub-scanning direction with respect to the position in each sub-scanning direction based on the thinning rate M. As shown in FIG. 5, the shift amount enlargement unit 145 _converts the shift amount data set to (M × d _sh ) between the line intervals indicated by the thinning rate M (for example, between the lines Y _m and Y _m + M). such as linear interpolation, the interpolation process as smoothly varies with the movement of the line, it may be converted into interpolated (expanded) in the slow-scan enlargement shift quantity data [Delta] y _b. In this case, since the interpolation is performed in units of M lines, the enlarged shift amount data Δy _b changes smoothly, and the displacement amount can be obtained with higher accuracy without the shift amount changing rapidly. Since the thinning rate M is set to an integer of 1 or more close to the scaling factor R that is the reading magnification, the circuit scale such as linear interpolation and averaging processing between the line intervals indicated by the thinning rate M is small. It can be converted into enlarged shift amount data Δy _b by processing.

<< 4-2-5 >> Operation of Join Processing Unit 146 The join processing unit 146 in the image processing unit 104 receives the enlarged shift amount data Δy _b output from the shift amount enlarging unit 145. The combination processing unit 146 calculates the read position RP of the image data based on the enlargement shift amount data Δy _b , reads the image data M146 corresponding to the read position, and subtracts the image data based on the enlargement shift amount data Δy _b. A process of moving in the scanning direction is performed, and the data in the overlap region of the image data is combined to generate composite image data.

FIG. 32 and FIGS. 33A and 33B are diagrams for explaining the operation of the combination processing unit 146. 32, only the data corresponding to the even-numbered line sensors 121E ₁ ,..., 121E _k ,..., 121E _n are positioned in the sub-scanning direction by an amount corresponding to the enlarged shift amount data Δy _b. may be shifted, as shown in shown in FIG. 33 (a) and (b), the line sensor 121 o ₁ located odd, _..., 121 o k, ..., data corresponding to 121 o _n, located in the even-numbered line sensors 121E ₁ to, _..., 121E k, _..., so that equivalent to both shift amount combined enlarge shift quantity data [Delta] y _b of the corresponding data to 121E _n, may be shifted to positions in the sub-scanning direction . In FIG. 33 (a) the image data at the position Y _m in the sub scanning direction read as a reference line (Y direction) by the read control unit 142, by an amount corresponding to the enlargement shift amount data [Delta] y _b in the adjacent line sensor shifting and, in FIG. 33 (b), the data of separated by an amount corresponding to the enlargement shift amount data [Delta] y _b in the adjacent line sensor position, are shifted to the position of the line Y _m.

That is, the combination processing unit 146 calculates the read position RP of the image data based on the enlargement shift amount data Δy _b , reads the image data M146 corresponding to the read position from the image memory 141, and sets the odd-numbered line. sensor _{_{121O 1, ..., 121O k,}} ..., 121O n data and the line sensor 121E ₁ located even-numbered, _..., 121E k, _..., the image data by combining the overlapping region data 121E _n overlap D146 Is generated. Since the enlargement shift amount data Δy _b is obtained as a value indicating the amount of misalignment corresponding to the line range changed by the scaling factor R, the image data read position RP is calculated based on the enlargement shift amount data Δy _b. In this case, even when the scaling process is performed, the reading position corresponding to each line corresponding to the scaling ratio can be obtained. At this time, without performing thinning or the like, in each line in the sub-scanning direction corresponding to the variable magnification, an image corresponding to the enlargement shift amount data Δy _b is used by using the image data of the position and the lines around the position. Since the data D146 is generated, the combined image does not deteriorate.

In the image processing unit 104, the read control unit 142, a position _{Y m} of a sub-scanning direction (Y-direction) as the reference line, the line sensor 121 o ₁ located odd in every M lines by thinning rate M, ..., 121O _k, ..., read image data in the overlap region corresponding to 121 o _n, the line sensor 121E ₁ located even-numbered, _..., 121E k, _..., the image data in the overlap region corresponding to 121E _n, pre The reference data MO and the comparison data ME of the determined number of lines are output, and the similarity calculation unit 143 compares the reference data MO and the comparison data ME to calculate similarity data (correlation data) D143, and shifts the data. The amount estimation unit 144 has the highest similarity for the detection reference line Y0 (the largest correlation). Calculates the position deviation amount corresponding to the sub scanning direction position of the stomach) comparison data as the shift quantity data d _sh, the shift amount larger portion 145, on the basis of the thinning rate M, the value of the shift amount data d _sh The image data is enlarged, repeatedly inserted in the sub-scanning direction, interpolated and converted into enlarged shift amount data Δy _b , and the combination processing unit 146 reads out the image data based on the enlarged shift amount data Δy _b and combines the combined image data D146. Output. This is sequentially performed in the sub-scanning direction (Y direction).

FIG. 34 is an image obtained by combining the images in FIG. 20C or FIG. 21C and FIGS. 22 to 25. Even in the case of the scaling process (FIGS. 24 and 25), the positional deviation amount in the sub-scanning direction (Y direction) is corrected in the same manner as in the case of the normal scaling process (R = 1) (FIGS. 22 and 23). Then, the image data of the same image as the original 160 shown in FIGS. 20B and 21B can be output. Particularly, in the case shown in FIG. 21 (c) or FIG. 23 and FIG. 25, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., the line sensor positioned in the image data and the even-numbered 121 o _n 121E ₁ ,..., 121E _k ,..., 121E _n are shifted in the sub-scanning direction (Y direction), but image data of the same image as the original 160 shown in FIG.

FIG. 34 is also an explanatory diagram conceptually showing the image data D146 after the combination process output from the combination processing unit 146. For any cases of the scaling process of the magnification process (R = 1), obtains a reading position corresponding to the magnification ratio from the enlarged shift quantity data [Delta] y _b, by an amount corresponding to the enlargement shift amount data [Delta] y _b because generates image data D146 with shifted position and a image data of a line near the position, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., line positioned in even-numbered and 121 o _n The displacement of the sensors 121E ₁ ,..., 121E _k ,..., 121E _{n in} the sub-scanning direction is corrected, and the overlapping area images that have been read are combined.

<< 4-2-6 >> Other Examples of Document 160 FIGS. 35A and 35B are diagrams illustrating an example in which the position of the document 160 with respect to the glass surface 126 changes while the imaging unit 102 is being conveyed. In the position _{Y m} in the sub-scanning direction (Y-direction), the original 160 is floated from the glass surface 126, the position Yu, the document 160 is adhered to the glass surface 126. Since the imaging unit 102 sequentially processes the image data at each position in the sub-scanning direction (Y direction), even if the position of the document 160 changes during conveyance, the image processing unit 104 determines the position at each position. Since the shift amount is calculated, the images can be combined correctly, and even in the case of the scaling process, the overlap area is obtained by thinning out the lines based on the thinning rate M set according to the scaling ratio. Image data is extracted to calculate the amount of misregistration, and the readout position at that position corresponding to the variable magnification is obtained by enlarging the obtained misregistration amount. Images can be combined. The line sensor 121 o ₁ located odd as described in FIG. 25 from FIG. 22, _..., 121 o k, ..., the line sensor 121E ₁ located to the even-numbered and _{_{121O n, ..., 121E k,}} ..., 121E _{Since the} shift amount is calculated individually for all _n , even if the position of the document 160 with respect to the glass surface 126 changes in the main scanning direction (X direction), the images can be combined correctly.

<< 4-3 >> Effects of the Fourth Embodiment As described above, in the image reading apparatus 101, the image processing apparatus 4, and the image processing method according to the fourth embodiment, the read control unit 142 uses the scaling factor. Of the image data read by the first row line sensor and the second row line sensor by thinning out the position (line) in the sub-scanning direction to be read out for each M lines with the thinning rate M set according to reads the data in the overlap regions, as a reference line position Y _m of a sub-scanning direction (Y direction), and outputs the comparison data ME with reference data MO of a predetermined number of lines, the similarity calculation unit 143 Then, the similarity data (correlation data) D143 is calculated by comparing the reference data MO and the comparison data ME, and the shift amount estimation unit 144 has the highest similarity. Enlarge calculates a positional deviation amount corresponding to the sub scanning direction position of the stomach comparison data as the shift quantity data d _sh, at the shift amount larger portion 145, on the basis of the thinning rate M, the value of the shift amount data d _sh and, have been converted into expanded shift quantity data [Delta] y _b interpolated repeatedly inserted in the sub-scanning direction, is shifted in the sub-scanning direction position of the divided image based on the enlargement shift amount data [Delta] y _b, bound Image data is generated.

Therefore, according to the thinning rate M set according to the scaling factor, the data in the overlap region is read for each M lines with the thinning rate M, and the reference data MO and the search range “−” that are not changed by the scaling factor. The comparison data ME for the number of lines in y to + y ″ can be obtained, the position misalignment search range is expanded, and the number or processing for generating similarity data is changed without changing according to the scaling factor. The shift amount data d _sh that is the shift amount can be calculated, and the shift amount data d _sh is enlarged and interpolated to obtain a position shift amount corresponding to the line range that is changed based on the magnification. As a result, combined image data can be generated. Therefore, even in the scaling process, the detection range of the amount of positional deviation in the sub-scanning direction is not expanded according to the scaling ratio. Obtain the position deviation amount in the sub-scanning direction between accurately image data without increasing the circuit scale, can generate high-quality combined image data corresponding to the read object.

Further, since the thinning rate M set in accordance with the scaling factor is set to an integer of 1 or more close to the scaling factor R that is the reading magnification, the thinning processing in the reading control unit 142 and the shift amount expanding unit 145 or The enlargement process does not need to be performed by an enlargement / reduction process by a filter operation such as line interpolation, and can be performed by a process with a small circuit scale.

<< 5 >> Embodiment 5
<< 5-1 >> Configuration of Embodiment 5 In the image reading apparatus 101, the image processing apparatus 4, and the image processing method according to Embodiment 4, the decimation rate M set based on the scaling ratio is set in the scaling process. The image data is sent to the read control unit 142 and the shift amount enlargement unit 145 in the image processing unit 104, the image data in the overlap region is read from the image memory 141 based on the thinning rate M, and the shift amount data is enlarged and reduced based on the thinning rate M. The shift amount data is converted into enlarged shift amount data by interpolation processing, and image data of the combined image is generated using the obtained enlarged shift amount data. On the other hand, as shown in FIG. 36, the image reading apparatus 101a according to the fifth embodiment has a position obtained from the scaling factor and the thinning rate M in addition to the thinning rate M set based on the scaling factor. The number LMT of search range exclusion lines that limit the search range of the shift amount is acquired, the image data in the overlap area is read from the image memory 141 based on the thinning rate M, and the shift amount data is expanded and expanded shift amount data by interpolation. In addition to the above conversion, the shift amount data d _sh that is the position shift amount is calculated by limiting (reducing) the search range of the position shift amount used at the time of shift amount estimation by the search range excluded line number LMT. You can also.

FIG. 36 is a functional block diagram schematically showing the configuration of the image reading apparatus 101a according to the fifth embodiment of the present invention. In FIG. 36, constituent elements that are the same as or correspond to those shown in FIG. 17 (Embodiment 4) are assigned the same reference numerals. The image reading apparatus 101a according to the fifth embodiment is different from the image reading apparatus 101 according to the fourth embodiment in the configuration and operation of the image processing unit 104a and the controller 107a. Except for the configuration and operation of the image processing unit 104a and the controller 107a, the image reading apparatus 101a according to the fifth embodiment is the same as the image reading apparatus according to the fourth embodiment. As shown in FIG. 36, the controller 107a in the fifth embodiment sends the thinning rate M and the search range excluded line number LMT set based on the scaling factor designated by the user or the like to the image processing unit 104a. . The image processing unit 104a uses the received thinning rate M and the search range excluded line number LMT to perform scaling processing and detection of the amount of positional deviation in the sub-scanning direction, and uses the detected amount of positional deviation to obtain image data. Join.

As shown in FIG. 36, the image reading apparatus 101a according to the fifth embodiment performs operations of the imaging unit 102, the A / D conversion unit 103, the image processing unit 104a, the imaging unit 102, and the image processing unit 104a. And a controller 107a to be controlled. The image processing unit 104a is an image processing apparatus according to the fifth embodiment (an apparatus that can perform the image processing method according to the fifth embodiment), and includes an image memory 141, a read control unit 142, and similarity calculation. A unit 143, a shift amount estimation unit 144a, a shift amount enlargement unit 145, and a combination processing unit 146. In the fifth embodiment, the shift amount estimation unit 144a uses the positional deviation amount corresponding to the position in the sub-scanning direction of the comparison data having the highest similarity (the highest correlation) based on the search range excluded line number LMT. Shift amount data is calculated. The configurations and operations of other components, for example, the imaging unit 102, the A / D conversion unit 103, the image memory 141, the read control unit 142, the similarity calculation unit 143, the shift amount enlargement unit 145, and the combination processing unit 146 are as follows. This is the same as that shown in the fourth embodiment.

<< 5-2 >> Operation of Embodiment 5 As with the controller 107 in FIG. 17, the controller 107a of the image reading apparatus 101a in FIG. 36 receives setting information or instruction information such as a variable magnification by the user, etc. The image is sent to the processing unit 104a, and the imaging unit 102 and the image processing unit 104a are controlled. In other words, when performing a scaling process, if the user specifies a scaling ratio, the controller 107a sends setting information for setting a reading magnification (magnification ratio) R to the imaging unit 102, and a thinning rate set based on the scaling ratio. M is sent to the image processing unit 104a. At this time, the controller 107a sets the search range excluded line number LMT based on the scaling factor, and sends the search range excluded line number LMT to the image processing unit 104a.

As in the case of the fourth embodiment, the controller 107a sets, as the thinning rate M, an integer of 1 or more close to the scaling factor R that is the reading magnification. In addition, the controller 107a may be a case where the scaling factor R is smaller than 1 (for example, R = 0.8) or an intermediate magnification having a fractional part in the scaling factor (for example, R = 1.5). When the range of the position in the sub-scanning direction (position shift amount) before the line is thinned by the thinning rate M exceeds the line range changed based on the magnification, the search range excluded line number LMT is Set the number of lines that limit the range of misregistration. At this time, even if the search range excluded line number LMT is a position shift amount value that can limit the search range of the position shift amount when estimating the shift amount, the similarity value is invalidated from the outside of the range. The number of lines may be such, or a signal indicating invalidity or validity at each position may be used. For example, when the scaling factor R is 0.8, the shift amount estimating unit 144a has a thinning rate M of 1. Therefore, the difference between the scaling factor R and the thinning rate M at the position in the sub-scanning direction outside the search range is 0. The amount of extra positional deviation is detected by an amount corresponding to 2 (= RM = 1-0.8). Therefore, in the fifth embodiment, the controller 107a sends the search range excluded line number LMT indicating a value for limiting (reducing) the search range of the extra positional shift amount corresponding to the difference of 0.2.

In FIG. 36, a document 160 is read by the imaging unit 102, converted into digital data (image data) DI by the A / D conversion unit 103, input to the image processing unit 104a, and stored in the image memory 141 of the image processing unit 104a. The The readout control unit 142 in the image processing unit 104a reads out data in the overlap region by thinning out the position (line) in the sub-scanning direction to be read out for each M lines with the thinning rate M set based on the variable magnification. The MO and the comparison data ME are output, and the similarity calculation unit 143 compares the reference data MO and the comparison data ME to calculate the similarity data (correlation data) D143. The configuration and operation described above in the fifth embodiment are the same as those in the fourth embodiment shown in FIG.

The shift amount estimation unit 144a receives from the similarity calculation unit 143 the correlation data D142 that is similarity data in the positional deviation amounts ΔY of a plurality of lines within the search range “−y to + y”, and receives a scaling factor from the controller 107a. The number LMT of search range exclusion lines set based on is received. The shift amount estimation unit 144a calculates a positional deviation amount ΔY corresponding to the data with the highest similarity among the correlation data D142 of the plurality of lines. At this time, the shift amount estimation unit 144a limits (reduces) the search range for obtaining data with the highest degree of similarity based on the search range excluded line number LMT, and within the limited (reduced) search range. The positional deviation amount ΔY corresponding to the data with the highest similarity is output to the shift amount enlargement unit 145 as the shift amount data d _sh .

Since the thinning-out rate M includes the scaling factor R or is set to an integer value close to the scaling factor, the positional deviation of a plurality of lines within the search range “−y to + y” from the similarity calculation unit 143 The amount ΔY is data in a range in which the original positional deviation amount ΔYa is read at intervals of M lines within “− (M × y) to + (M × y)”, and the thinning rate M is larger than the scaling factor R. If it is a value, the search range has an excessive amount (that is, it is too wide), and an excessive amount of misalignment is detected. For example, when the scaling ratio R = 1.5 and the thinning rate M = 2, the positional deviation amount ΔYa is read as comparison range “−2y to + 2y” at two line intervals. However, the search range “−2y to + 2y” is outside the search range “−1.5y to + 1.5y” as compared to the search range “−1.5y to + 1.5y” that is changed with the actual scaling factor. In the region corresponding to the number of position lines 0.5y in the sub-scanning direction (that is, 0.5y = 2y−1.5y), an excessive amount of displacement is detected. An area corresponding to the number of lines 0.5y outside the search range “−1.5y to + 1.5y” becomes an excessive search range, which may cause erroneous detection of shift amount data (position shift amount). Therefore, in this case, the controller 107a sets a value indicating an area corresponding to the number of lines 0.5y outside the search range “−1.5y to + 1.5y” as the search range excluded line number LMT, and shifts it. It supplies to the quantity estimation part 144a.

Then, the shift amount estimating unit 144a invalidates the search range so that the correlation data D142 at the positional deviation amount indicated by the search range excluded line number LMT is not included in the search range, and sets the search range to the range “− (y−LMT) to + (y In the line limited to “−LMT)”, the shift amount ΔY corresponding to the data with the highest similarity is used as the shift amount data d _sh . In FIG. 37, the search range is ΔY as a curve indicated by a broken line as a line limited within the range “− (y−LMT) to + (y−LMT)” within the search range “−y to + y”. When the similarity is high at the position of = 0 (that is, the dissimilarity is low), ΔY = 0 is used as the shift amount data d _sh, and at the position of ΔY = −α like the curve shown by the solid line. When the similarity is the highest (that is, the dissimilarity is the lowest), ΔY = −α is set as the shift amount data d _sh .

From the above, based on the search range excluded line number LMT, the shift amount estimation unit 144a limits the range for which data with the highest degree of similarity is obtained to the range “− (y−LMT) to + (y−LMT)”. (Reduction), and the positional deviation amount ΔY corresponding to the data with the highest similarity within the limited range is obtained as the shift amount data d _sh . 8) or an intermediate magnification having a fractional part (for example, R = 1.5), the search range based on the thinning-out rate M has a range for detecting an excessive amount of misalignment. even when the excessive, it is possible to obtain the positional deviation amount ΔY the similarity corresponding to the highest deviation data in an appropriate range as the shift quantity data d _sh, by an easy process of limiting the scope, increase in circuit scale No need to perform, it is possible to accurately search for positional deviation amount.

Thereafter, in the image processing unit 104a, the shift amount enlargement unit 145 enlarges and interpolates the shift amount data d _sh to convert it to enlargement shift amount data Δy _b , and the combination processing unit 146 converts it into the enlargement shift amount data Δy _b . The configuration and operation of generating the combined image data by shifting the position of the divided image in the sub-scanning direction based on the same as that shown in the fourth embodiment (FIG. 17).

<< 5-3 >> Effects of Embodiment 5 As described above, in the image reading apparatus 101a, the image processing apparatus 4a, and the image processing method according to Embodiment 5, thinning set based on the scaling factor. According to the rate M, the data in the overlap region is read for each M lines at the thinning rate M, and the reference data MO that is not changed by the scaling factor is compared with the number of lines in the search range “−y to + y” The data ME can be obtained, the search range of the positional deviation amount can be expanded, the shift amount data d _sh can be calculated without changing the number or processing of generating similarity data based on the scaling factor, and the search Even if the range is excessive, the search range for which data with the highest degree of similarity is determined (reduced) is limited (reduced) based on the number LMT of search range exclusion lines, and the position shifts within an appropriate range. By it with the shift quantity data d _sh can be calculated, by expanding and interpolating the shift amount data d _sh, obtained as a value indicating a positional deviation amount corresponding to a line range is changed based on the magnification The combined image data can be generated. Therefore, according to the image reading apparatus 101a, the image processing apparatus 4a, and the image processing method according to the fifth embodiment, even in the scaling process, the detection range of the positional deviation amount in the sub-scanning direction is expanded based on the scaling ratio. Therefore, it is possible to accurately obtain the positional deviation amount in the sub-scanning direction between the image data without increasing the circuit scale, and to generate high-quality composite image data corresponding to the object to be read.

<< 6 >> Embodiment 6
<< 6-1 >> Configuration of Embodiment 6 The functions of the image reading apparatuses 101 and 1a according to Embodiments 4 and 5 can be realized by a hardware configuration. However, some of the functions of the

image reading apparatuses

101 and 101a may be realized by using a computer program executed by a microprocessor including a CPU. When a part of the functions of the

image reading apparatuses

101 and 101a is realized by using a computer program, the microprocessor reads program data stored in a computer-readable information storage medium, or the Internet The computer program is acquired by downloading via the communication means, and processing according to the acquired computer program is executed.

FIG. 38 is a functional block diagram showing a configuration of the image reading apparatus 101b when a part of the functions of the image reading apparatus 101b according to the sixth embodiment is realized by a computer program. As illustrated in FIG. 38, the image reading apparatus 101b according to the sixth embodiment includes an imaging unit 102, an A / D conversion unit 103, and an arithmetic device 105. The arithmetic unit 105 includes a processor (for example, a microprocessor) 151 including a CPU, a RAM 152 as a volatile memory, a nonvolatile memory 153, a mass storage medium 154 as an information recording medium, and the above-described configurations 151 to 154. And a bus 155 connected thereto. The non-volatile memory 153 is, for example, a flash memory. The mass storage medium 154 is, for example, a hard disk (magnetic disk), an optical disk, or a semiconductor storage device.

The A / D converter 103 shown in FIG. 38 has the same function as the A / D converter 103 shown in FIGS. 17 and 36, and converts the electrical signal SI output from the imaging unit 102 into digital data DI. To the processor 151. The processor 151 stores the supplied digital data in the RAM 152.

The processor 151 loads a computer program from the nonvolatile memory 153 or the large-capacity storage medium 154 and sets a thinning rate M set based on the scaling factor (or the thinning rate M and the number of search range excluded lines) Set the LMT) and execute image processing. By this image processing, image processing similar to the image processing by the

image processing units

104 and 104a shown in FIGS. 17 and 36 can be realized.

<< 6-2 >> Operation of the Sixth Embodiment FIG. 39 is a flowchart schematically showing an example of processing by the arithmetic unit 105 of the sixth embodiment. As shown in FIG. 39, the processor 151 first uses the thinning rate M set based on the scaling factor (or uses the thinning rate M and the search range excluded line number LMT). The data in the overlap region is read out, and a read control process is executed so as to extract the reference data MO and the comparison data ME with a predetermined number of lines (step S101), and the reference data MO and the comparison data ME are compared. A similarity calculation process is executed (step S102). Thereafter, the processor 151 executes a shift amount estimation process (step S103), and expands and interpolates the shift amount data using the thinning rate M (or using the thinning rate M and the search range excluded line number LMT). A shift amount enlargement process is executed (step S104). Finally, the processor 151 executes a combination process (step S105). Note that the processing in steps S1 to S5 by the arithmetic device 105 is the same as the processing performed by the image processing unit 104 in the fourth embodiment or the processing performed by the image processing unit 104a in the fifth embodiment.

<< 6-3 >> Effects of the Sixth Embodiment As described above, in the image reading apparatus 101b according to the sixth embodiment, the number or processing of generating the similarity data by expanding the search range of the positional deviation amount. the without changing according to the magnification ratio, can be calculated shift amount data d _sh, by expanding and interpolating the shift amount data d _sh, the positional deviation amount corresponding to a line range is changed based on the magnification It can be obtained as a value to indicate and combined image data can be generated. For this reason, according to the image reading apparatus 101b according to the sixth embodiment, even in the scaling process, the accuracy without increasing the circuit scale without expanding the detection range of the positional deviation amount in the sub-scanning direction according to the scaling ratio. It is often possible to obtain the amount of positional deviation in the sub-scanning direction between image data, and to generate high-quality composite image data corresponding to the object to be read.

<< 7 >> Embodiment 7
<< 7-1 >> Configuration of Embodiment 7 In Embodiment 4, as shown in FIG. 20 (a), the odd-numbered positions counted from one end (for example, the left end) of the sensor substrate 120 are provided. line sensor 121 o ₁ to, _..., 121O k, _..., the line sensor 121E ₁ located to the even-numbered and the optical axis 127O of _{_{121O n, ..., 121E k,}} ..., illustrating a case where the optical axis 127E of 121E _n intersect did. In the seventh embodiment, one end of the sensor substrate 120 (e.g., left) line sensor 121 o ₁ located odd counted from the side, _..., 121 o k, ..., even-numbered and the optical axis 128O of 121 o _n line sensors 121E ₁ located, _..., 121E k, _..., not intersect with the optical axis 128E of 121E _n, it will be described the case of installing the line sensor so as to be parallel. Incidentally, the line sensor _{_{121O 1, ..., 121O k,}} ..., between 121 o _n and the glass surface 126, and the line sensor _{_{121E 1, ..., 121E k,}} ..., between the 121E _n and the glass surface 126, An optical system such as a lens for forming an image of a document on a line sensor may be provided. The direction of the optical axis 128O and the direction of the optical axis 128E can also be set by an optical system provided between the line sensor and the glass surface 126. The image reading apparatus according to the seventh embodiment, the line sensor _{_{121O 1, ..., 121O k,}} ..., the optical axis 128O and the line sensor 121E ₁ of _{_{121O n, ..., 121E k,}} ..., and the optical axis 128E of 121E _n Except for the fact that they are parallel to each other, this is substantially the same as the image reading apparatus 101 according to the fourth embodiment. Therefore, FIG. 17 is also referred to in the description of the seventh embodiment.

<< 7-2 >> Operation of Embodiment 7 FIGS. 40 (a) and 40 (b) show line sensors 121O ₁ ,..., 121O _k located at odd-numbered positions of the imaging unit 102 of the image reading apparatus according to Embodiment 7. FIG. , ..., the line sensor 121E ₁ located to the even-numbered and the optical axis 128O of 121 o _n, _..., 121E k, ..., if the optical axis 128E of 121E _n are parallel to each other, the document 160 as an object to be read was It is a schematic side view which shows the positional relationship of the line sensors 121O and 121E. FIG. 40A shows a case where the document 160 is in close contact with the glass surface 126 which is the document table mounting surface, and FIG. 40B shows a case where the document 160 is slightly lifted away from the glass surface 126. Indicates.

In the image reading apparatus according to the seventh embodiment, when document 160 is in close contact with glass surface 126 as shown in FIG. 40A, document 160 is glass as shown in FIG. be any of the case away from the surface 126, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., the read image of the document 160 by 121 o _n hardly changes, similarly, the even-numbered line sensors 121E ₁ located, _..., 121E k, _..., the read image of the document 160 by 121E _n is hardly changed. Also, when the imaging unit 102 in the sub-scanning direction (Y direction) is conveyed, the line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O n is the line sensor 121E ₁ located even number, _..., 121E _{k, ...,} compared to the 121E _n, obtains the image data of the image in the same position temporally delayed. Since the optical axis 128O and the optical axis 128E are parallel, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., and the image reading is 121 o _n, the line sensor 121E ₁ located even-numbered, ..., 121E _k, ..., shift amount _{L 1} in the sub-scanning direction position of the image to be read is 121E _n can be obtained as a substantially constant amount. Shift amount _{L 1} is the line sensor 121 o ₁ located _{odd, ..., 121O k, ...,} 121O n and the line sensor 121E ₁ located even-numbered, _..., 121E k, ..., sub between 121E _n comprising a predetermined amount Y _L corresponding to the scanning direction of the spacing (distance), and other positional deviation amount beta. That is,
L ₁ = Y _L + β
It is. Here, the positional deviation amount β is caused by the deviation amount of the optical axis 128O or the optical axis 128E due to the attachment error of the line sensor and the temporal fluctuation (that is, speed fluctuation) of the conveyance speed of the imaging unit 102 in the sub-scanning direction. It is a value including a deviation amount based on it.

FIG. 41 shows image data DI (O _k ) and DI (O _{k + 1} ) corresponding to the even-numbered line sensors 121O _k and 121O _{k + 1} when the document is read, and the odd-numbered

line sensors

121E _k and 121E. image data _DI corresponding to _{k + 1} (E _k), shows the DI _{(E k + 1).} As shown in FIG. 41, the image data DI (O _k ) and DI (O _{k + 1} ) corresponding to the even-numbered line sensors 121O _k and 121O _{k + 1} and the odd-numbered

line sensors

121E _k and 121E _{k + 1} Corresponding image data DI (E _k ) and DI (E _{k + 1} ) are displaced from each other by a distance (Y _L + β) in which the position (line) in the sub-scanning direction is obtained by adding a positional deviation amount β to a certain amount Y _L. ing.

Therefore, in the image processing section 104, when writing the image data in the image memory 141, the line sensor 121 o ₁ located odd, _..., 121 o k, ..., scanned image by 121 o _n, or located in the even-numbered line sensors 121E ₁ to, _..., 121E k, ..., either one of the image reading by 121E _n, or both, by performing a substantially constant amount _{Y L} shifting process in the sub-line located in the odd-numbered sensor _{_{121O 1, ..., 121O k,}} ..., the line sensor 121E ₁ located to the image and the even-numbered reading by _{_{121O n, ..., 121E k,}} ..., the sub-scanning direction positional shift between the image reading by 121E _n Decrease. By such processing, as shown in FIG. 42, the image data stored in the image memory 141 shifts (shifts) the position (line) in the sub-scanning direction by a distance equal to the positional shift amount β. Stored in the image memory 141.

Time scaling processing, as in the fourth embodiment, is enlarged or reduced by the magnification of the magnification ratio R is in the sub-expansion by a factor of a predetermined amount Y _L and the position deviation amount β magnification R also Or it will be reduced. Therefore, the image processing unit 104 shifts ( _L × Y _L ) lines, which is the number of lines obtained by multiplying Y _L by R equal to the variable magnification, instead of the process of shifting the predetermined amount Y _L when writing image data to the image memory 141. Process. In the above description has exemplified the case where the process of shifting the image data when writing to the image memory 141 by an amount corresponding to a predetermined amount Y _L in the sub-scanning direction, the read control unit 142 and the connection processing unit 146 in the case of reading the image data, it may be configured to determine the position added as offset to the position to read out the predetermined amount Y _L.

In the image processing unit 104, the positional deviation amount β is obtained and the images are combined. Based on the thinning rate M set in accordance with the variable magnification R, the overlap region in the image data from the image memory 141 is obtained. The image data is read out, the reference data is compared with the comparison data, the similarity is calculated, the shift amount data is calculated from the position of the comparison data with the highest similarity in the sub-scanning direction, and based on the thinning rate M Enlarged shift amount data obtained by enlarging the shift amount data in the sub-scanning direction is obtained, and the image data is read from the image memory 141 by the enlarged shift amount data and combined. The configuration and operation for performing such processing are the same as those in the fourth embodiment.

<< 7-3 >> Effects of Embodiment 7 As described above, according to the image reading apparatus of Embodiment 7, either the document 160 or the imaging unit 102, or Even in the case where there is temporal fluctuation (that is, speed fluctuation) in the transport speed by the transport mechanism when moving both in the sub-scanning direction, as in the case of the fourth embodiment, depending on the magnification ratio. Without increasing the detection range of the amount of misalignment in the sub-scanning direction, without increasing the circuit scale, the amount of misalignment in the sub-scanning direction between the image data can be obtained accurately, and the combined image data is obtained by accurately combining the image data. Can be generated.

The image processing apparatus, image processing method, image reading apparatus, and program according to the present invention can be applied to information processing apparatuses such as a copying machine, a scanner, a facsimile, and a personal computer.

1,1a image reading apparatus, second imaging unit, 3 A / D conversion unit, 4 an image processing section (image processing apparatus), 5 calculation unit, 20 sensor _{_{substrate, 21O 1, ..., 21O k}} , ..., 21O n odd 21E ₁ ,..., 21E _k ,..., 21E _n even-numbered line sensors, 22 spacing between odd-numbered adjacent line sensors, and 23 even-numbered adjacent lines 25. Light source, 26R Photoelectric conversion element for red light, 26G Photoelectric conversion element for green light, 26B Photoelectric conversion element for blue light, 27O, 28O Optical axes of line sensors positioned at odd numbers 27E, 28E Optical axes of even-numbered line sensors, 41 image memory, 42 similarity calculation unit, 43 shift amount estimation unit, 44 combination processing unit, 51 step Processor, 52 RAM, 53 Non-volatile memory, 54 Mass storage medium, 60 Document, D42 Correlation data, D43 Shift amount data, M44 image data, D44 image data, 101, 101a, 101b Image reader, 102 Imaging unit, 103 a / D conversion unit, 104, 104a an image processing section (image processing device), 105 arithmetic unit, 107 and 107a controller, 120 sensor _{_{substrate, 121O 1, ..., 121O k}} , ..., 121O n, located in odd-numbered 121 o line _{_{sensor, 121E 1, ..., 121E k}} , ..., 121E n, the line sensor located numbered 121E, the right end of the region of sr line sensor, the left end of the region of the sl line sensor, _a 1, 1, ..., _{a k _{_{, k, A k, k +}}} 1, A k + 1, k + 1, ..., A n, n -Burlap region (overlapping region), 125 illumination light source, 126 glass surface, 126R red light photoelectric conversion device, 126G green red light photoelectric conversion device, 126B blue light photoelectric conversion device, 127O, 128O odd-numbered line sensors , 127E, 128E optical axes of even-numbered line sensors, 141 image memory, 142 readout control unit, 143 similarity calculation unit, 144, 144a shift amount estimation unit, 145 shift amount enlargement unit, 146 combination processing , 151 processor, 152 RAM, 153 nonvolatile memory, 154 mass storage medium, 160 original, SI electrical signal (image data), DI digital data (image data), rMO image data, rME image data, MO image data, ME image data, D143 correlation data Data, _{d sh} shift amount data, [Delta] y _b larger shift amount data, RP read position data, M146 image data, D146 image data, the transport direction of Dy imaging unit.

Claims

A first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and arranged at different positions in the sub scanning direction from the first row of line sensor groups. And a second row line sensor group including a plurality of second line sensors arranged in a line at a second interval in the main scanning direction, wherein the first row line sensor The plurality of first line sensors belonging to a group are arranged to face the second interval in the second row line sensor group, and the plurality of second line sensors belonging to the second row line sensor group Line sensors are arranged so as to face the first interval in the line sensor group of the first row, and adjacent ends of the first line sensor and the second line sensor adjacent to each other are in the main scanning. Overlapping direction An image processing apparatus for processing the image data generated by the imaging unit having a Rappu region,
An image memory storing first image data based on detection signals generated by the first row of line sensor groups and second image data based on detection signals generated by the second row of line sensor groups;
Of the first image data read from the image memory, read from the image memory in the same overlap area as the reference data having a predetermined first width in the sub-scanning direction in the overlap area. The process of comparing the comparison data selected from the second image data and the comparison data having the same width as the first width is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, A similarity calculator that calculates the similarity between the reference data and the comparison data;
A shift amount estimation unit that calculates shift amount data based on a difference between a position in the sub-scanning direction of the reference data and a position in the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data;
The first image data and the second image data are read from the image memory, the shift amount indicated by the shift amount data is divided, and the first shift amount data indicating one of the divided shift amounts and the Second shift amount data indicating the other divided shift amount is generated, the position of the first image data in the sub-scanning direction is corrected based on the first shift amount data, and the second shift amount data is corrected. A combination processing unit that corrects a position of the second image data in the sub-scanning direction based on shift amount data, and combines the first image data and the second image data. An image processing apparatus.
The combination processing unit is configured to combine the position of the first image data in the sub-scanning direction and the position of the second image data in the sub-scanning direction when combining the first image data and the second image data. The image processing apparatus according to claim 1, wherein the position is changed according to a position in the main scanning direction.
The image processing apparatus according to claim 1, wherein the similarity calculation unit uses an absolute value of a difference for each pixel between the reference data and the comparison data as the similarity.
2. The image processing apparatus according to claim 1, wherein the similarity calculation unit uses a sum of squares of differences between the reference data and the comparison data for each pixel as the similarity.
5. The method according to claim 1, wherein the combination processing unit corrects one of the line sensor group in the first row and the line sensor group in the second row based on the shift amount data. The image processing apparatus according to claim 1.
5. The method according to claim 1, wherein the combination processing unit corrects both the first row line sensor group and the second row line sensor group based on the shift amount data. The image processing apparatus according to item.
A first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and arranged at different positions in the sub scanning direction from the first row of line sensor groups. And a second row line sensor group including a plurality of second line sensors arranged in a line at a second interval in the main scanning direction, wherein the first row line sensor The plurality of first line sensors belonging to a group are arranged to face the second interval in the second row line sensor group, and the plurality of second line sensors belonging to the second row line sensor group Line sensors are arranged so as to face the first interval in the line sensor group of the first row, and adjacent ends of the first line sensor and the second line sensor adjacent to each other are in the main scanning. Overlapping direction An image processing apparatus for processing the image data generated by the imaging unit having a Rappu region,
An image memory storing first image data based on detection signals generated by the first row of line sensor groups and second image data based on detection signals generated by the second row of line sensor groups;
Of the first image data read from the image memory, read from the image memory in the same overlap area as the reference data having a predetermined first width in the sub-scanning direction in the overlap area. The process of comparing the comparison data selected from the second image data and the comparison data having the same width as the first width is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, A similarity calculator that calculates the similarity between the reference data and the comparison data;
A shift amount estimation unit that calculates shift amount data based on a difference between a position in the sub-scanning direction of the reference data and a position in the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data;
The first image data and the second image data are read from the image memory, and the first image data and the second image data are changed based on the shift amount data by changing the coupling position in the sub-scanning direction. An image processing apparatus comprising: a combining processing unit that combines
A first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and arranged at different positions in the sub scanning direction from the first row of line sensor groups. And a second row line sensor group including a plurality of second line sensors arranged in a line at a second interval in the main scanning direction, wherein the first row line sensor The plurality of first line sensors belonging to a group are arranged to face the second interval in the second row line sensor group, and the plurality of second line sensors belonging to the second row line sensor group Line sensors are arranged so as to face the first interval in the line sensor group of the first row, and adjacent ends of the first line sensor and the second line sensor adjacent to each other are in the main scanning. Overlapping direction An image processing method for processing image data generated by the imaging unit having a Rappu region,
Read from an image memory storing first image data based on detection signals generated by the first row of line sensor groups and second image data based on detection signals generated by the second row of line sensor groups. Of the output first image data, the reference data having a predetermined first width in the sub-scanning direction in the overlap region and the second data read from the image memory in the same overlap region. A process of comparing comparison data having the same width as the first width selected from the image data is performed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data and the Calculating the degree of similarity with the comparison data;
Calculating shift amount data based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest similarity among the plurality of comparison data in the sub-scanning direction;
The first image data and the second image data are read from the image memory, and the first image data and the second image data are changed based on the shift amount data by changing the coupling position in the sub-scanning direction. And an image processing method.
A first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and arranged at different positions in the sub scanning direction from the first row of line sensor groups. And a second row line sensor group including a plurality of second line sensors arranged in a line at a second interval in the main scanning direction, wherein the first row line sensor The plurality of first line sensors belonging to a group are arranged to face the second interval in the second row line sensor group, and the plurality of second line sensors belonging to the second row line sensor group Line sensors are arranged so as to face the first interval in the line sensor group of the first row, and adjacent ends of the first line sensor and the second line sensor adjacent to each other are in the main scanning. Overlapping direction And the imaging section having Rappu area,
An image memory storing first image data based on detection signals generated by the first row of line sensor groups and second image data based on detection signals generated by the second row of line sensor groups;
Of the first image data read from the image memory, read from the image memory in the same overlap area as the reference data having a predetermined first width in the sub-scanning direction in the overlap area. The process of comparing the comparison data selected from the second image data and the comparison data having the same width as the first width is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, A similarity calculator that calculates the similarity between the reference data and the comparison data;
A shift amount estimation unit that calculates shift amount data based on a difference between a position in the sub-scanning direction of the reference data and a position in the sub-scanning direction of the comparison data having the highest similarity among the plurality of comparison data;
The first image data and the second image data are read from the image memory, and based on the shift amount data, the coupling position in the sub-scanning direction is changed to change the first image data and the second image data. An image reading apparatus comprising: a combining processing unit that combines
A first row of line sensor groups including a plurality of first line sensors arranged in a line at a first interval in the main scanning direction, and arranged at different positions in the sub scanning direction from the first row of line sensor groups. And a second row line sensor group including a plurality of second line sensors arranged in a line at a second interval in the main scanning direction, wherein the first row line sensor The plurality of first line sensors belonging to a group are arranged to face the second interval in the second row line sensor group, and the plurality of second line sensors belonging to the second row line sensor group Line sensors are arranged so as to face the first interval in the line sensor group of the first row, and adjacent ends of the first line sensor and the second line sensor adjacent to each other are in the main scanning. Overlapping direction For processing the image data generated by the imaging unit having a Rappu area, a program executable by a computer,
Read from an image memory storing first image data based on detection signals generated by the first row of line sensor groups and second image data based on detection signals generated by the second row of line sensor groups. Of the output first image data, the reference data having a predetermined first width in the sub-scanning direction in the overlap region and the second data read from the image memory in the same overlap region. A process of comparing comparison data having the same width as the first width selected from the image data is performed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data and the A process of calculating the similarity with the comparison data;
A process of calculating shift amount data based on a difference between a position in the sub-scanning direction of the reference data and a position in the sub-scanning direction of comparison data having the highest similarity among the plurality of comparison data;
The first image data and the second image data are read from the image memory, and the first image data and the second image data are changed based on the shift amount data by changing the coupling position in the sub-scanning direction. A program that causes a computer to execute the process of combining.
An overlap region in which line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction have at least two rows at different positions in the sub-scanning direction, and ends of adjacent line sensors in different rows overlap in the main scanning direction In an image processing apparatus for processing image data generated by an imaging unit arranged to have
An image memory for storing image data based on an output from the line sensor;
Based on the thinning rate set according to the reading magnification in the sub-scanning direction by the line sensor, the reference data at the position in the predetermined sub-scanning direction in the overlap region from the image data stored in the image memory. And a read control unit that reads comparison data in a region that overlaps the overlap region of the reference data;
The process of comparing the reference data read by the read control unit and the comparison data is performed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data and the plurality of sub-data are compared. A similarity calculation unit for calculating a similarity with the comparison data for the position in the scanning direction;
Shift amount data is calculated based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest degree of similarity in the plurality of sub-scanning direction positions in the sub-scanning direction A shift amount estimation unit to perform,
A shift amount enlargement unit that converts the shift amount data into enlarged shift amount data by enlarging and interpolating the shift amount data in the sub-scanning direction based on the thinning rate;
The position of the image data read from the image memory in the sub-scanning direction is determined based on the enlargement shift amount data, the image data at the determined position is read from the image memory, and the adjacent line sensors in different columns An image processing apparatus comprising: a combination processing unit that generates combined image data by combining the image data read out by step (a).
The read control unit
When reading and outputting the reference data and the comparison data from the image memory based on the thinning rate,
The reference data at a predetermined position in the sub-scanning direction in the overlap region;
In the overlap region, the comparison data at the position in the sub-scanning direction with a predetermined number of lines selected from the image data at the same position as the position in the sub-scanning direction of the reference data and the position in the sub-scanning direction before and after the reference data The image processing apparatus according to claim 11, wherein:
The thinning rate is set based on the number of reading lines in the sub-scanning direction enlarged or reduced according to the reading magnification,
The read control unit
When reading image data at a position in a predetermined sub-scanning direction in an overlap area of the image data from the image memory,
For each line interval in the sub-scanning direction of the number of lines corresponding to the thinning rate, the reference data at a position in the predetermined sub-scanning direction in the overlap area, the same position as the sub-scanning position of the reference data, and the sub-scans before and after that Reading out the image data while thinning out the image data so that the predetermined number of lines selected from the image data at the position in the scanning direction and the comparison data at the position in the sub-scanning direction are read out, and outputting the reference data and the comparison data The image processing apparatus according to claim 11, wherein:
The thinning rate is set based on the number of reading lines in the sub-scanning direction enlarged or reduced according to the reading magnification,
The read control unit
When reading image data at a position in a predetermined sub-scanning direction in an overlap area of the image data from the image memory,
The image data is read out for each line interval in the sub-scanning direction corresponding to the number of thinning rates, the image data is averaged in the sub-scanning direction in units of the line interval, and a predetermined value in the overlap region is determined. The reference data at the position in the sub-scanning direction and the comparison at a predetermined number of positions in the sub-scanning direction selected from the image data at the same position as the position of the reference data or the position in the sub-scanning direction before and after the reference data. It outputs as data. The image processing apparatus of Claim 11 or 12 characterized by the above-mentioned.
The shift amount enlargement unit converts the value of the shift amount data using a magnification according to the thinning rate, and the shift amount data for each line interval in the sub-scanning direction of the number of lines according to the thinning rate. 12. The shift amount data is converted into the enlarged shift amount data by repeatedly inserting the shift amount data and performing an interpolation process in the sub-scanning direction until the next line for which is required. The image processing apparatus described.
The shift amount enlargement unit converts the value of the shift amount data using a magnification according to the decimation rate, and from the shift amount data in the line for which the shift amount data is obtained, the number of lines according to the decimation rate The image processing apparatus according to claim 11, wherein the shift amount data is converted into the enlarged shift amount data by performing interpolation processing in the sub-scanning direction by interpolation processing for lines in the sub-scanning direction.
The image processing apparatus according to any one of claims 11 to 16, wherein the thinning rate is an integer of 1 or more.
The shift amount estimation unit includes:
The range of the position in the sub-scanning direction of the comparison data used for calculating the shift amount data is determined by the number of search range excluded lines set based on the reading magnification in the sub-scanning direction by the line sensor and the thinning rate. Further processing to limit,
Calculating the shift amount data based on a difference between a position of the reference data in the sub-scanning direction and a position of the comparison data having the highest similarity in the plurality of positions in the sub-scanning direction. The image processing apparatus according to claim 11, wherein the image processing apparatus is characterized in that:
The combination processing unit includes:
Based on the enlargement shift amount data, calculate the position in the sub-scanning direction of the image data read from the image memory,
The composite image data is generated using the image data at the calculated position in the sub-scanning direction and the image data of an adjacent line at the calculated position in the sub-scanning direction. The image processing apparatus according to any one of 18 to 18.
An overlap region in which line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction have at least two rows at different positions in the sub-scanning direction, and ends of adjacent line sensors in different rows overlap in the main scanning direction In an image processing method for processing image data generated by an imaging unit arranged to have
A storage step of storing image data based on an output from the line sensor in an image memory;
Based on the thinning rate set according to the reading magnification in the sub-scanning direction by the line sensor, the reference data at the position in the predetermined sub-scanning direction in the overlap area from the image data stored in the image memory. And a read control step of reading comparison data in a region overlapping the overlap region of the reference data;
The process of comparing the reference data read in the reading step and the comparison data is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, and the reference data and the plurality of sub-scans A similarity calculation step of calculating the similarity with the comparison data for the position in the direction;
Shift amount data is calculated based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest degree of similarity in the plurality of sub-scanning direction positions in the sub-scanning direction A shift amount calculating step,
A shift amount enlargement step for converting the shift amount data into enlarged shift amount data by enlarging and interpolating the shift amount data in the sub-scanning direction based on the thinning rate;
The position of the image data read from the image memory in the sub-scanning direction is determined based on the enlargement shift amount data, the image data at the determined position is read from the image memory, and the adjacent line sensors in different columns An image processing method comprising: a combination processing step of generating composite image data by combining the image data read out by the step.
An overlap region in which line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction have at least two rows at different positions in the sub-scanning direction, and ends of adjacent line sensors in different rows overlap in the main scanning direction An imaging unit arranged to have
An image memory for storing image data based on an output from the line sensor;
Based on the thinning rate set according to the reading magnification in the sub-scanning direction by the line sensor, the reference data at the position in the predetermined sub-scanning direction in the overlap region from the image data stored in the image memory. And a read control unit that reads comparison data in a region that overlaps the overlap region of the reference data;
The process of comparing the reference data read by the read control unit and the comparison data is performed for a plurality of positions where the positions of the comparison data are moved in the sub-scanning direction, and the reference data and the plurality of sub-data are compared. A similarity calculation unit for calculating a similarity with the comparison data for the position in the scanning direction;
Shift amount data is calculated based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest degree of similarity in the plurality of sub-scanning direction positions in the sub-scanning direction A shift amount estimation unit to perform,
A shift amount enlargement unit that converts the shift amount data into enlarged shift amount data by enlarging and interpolating the shift amount data in the sub-scanning direction based on the thinning rate;
A position in the sub-scanning direction of the image data read from the image memory is determined based on the enlargement shift amount data, the image data at the determined position is read from the image memory, and the adjacent line sensors in different columns An image reading apparatus comprising: a combining processing unit that generates combined image data by combining the image data read out by step (a).
An overlap region in which line sensors including a plurality of photoelectric conversion elements arranged in the main scanning direction have at least two rows at different positions in the sub-scanning direction, and ends of adjacent line sensors in different rows overlap in the main scanning direction A program for causing a computer to execute processing of image data generated by an imaging unit arranged to have
A storage process for storing image data based on an output from the line sensor in an image memory;
Based on the thinning rate set according to the reading magnification in the sub-scanning direction by the line sensor, the reference data at the position in the predetermined sub-scanning direction in the overlap region from the image data stored in the image memory. And a read control process for reading comparison data in a region overlapping the overlap region of the reference data;
The process of comparing the reference data read in the reading step and the comparison data is performed for a plurality of positions where the position of the comparison data is moved in the sub-scanning direction, and the reference data and the plurality of sub-scans Similarity calculation processing for calculating the similarity with the comparison data for the position in the direction;
Shift amount data is calculated based on the difference between the position of the reference data in the sub-scanning direction and the position of the comparison data having the highest degree of similarity in the plurality of sub-scanning direction positions in the sub-scanning direction Shift amount calculation processing,
A shift amount enlargement step for converting the shift amount data into enlarged shift amount data by enlarging and interpolating the shift amount data in the sub-scanning direction based on the thinning rate;
The position of the image data read from the image memory in the sub-scanning direction is determined based on the enlargement shift amount data, the image data at the determined position is read from the image memory, and the adjacent line sensors in different columns A program that causes a computer to execute a combining process for generating composite image data by combining the image data read out by.