JP2000172844A - Printing inspection method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing inspection device which can inspect the whole surface of a printed matter in detail at a high speed. SOLUTION: A reference picture inputted from a picture inputting section 101 is stored in a reference picture storing section 103 and an area deciding section 104 divides the reference picture into a plurality of areas. A reference value deciding section 108 extracts characteristic amounts at every divided area and stores the extracted amounts in a reference value storing section 109. The inputting section 101 inputs a picture to be inspected and the picture is stored in the storing section 102. An area selecting section 105 divides the picture to be inspected into areas of the same number as that of the areas divided by the deciding section 108, extracts feature amounts at every divided areas, and stores the extracted amounts in an accumulating section 106. A general situation comparing section 107 discriminates the areas where the difference between both feature amounts exceeds an allowable amount, by comparing the feature amounts in the storing section 109 with those in the accumulating section and a detail comparing section 111 inspects the areas discriminated by means of the comparing section 111 for printing defects based on the reference picture in the reference picture storing section 103 and the picture to be inspected in the picture storing section 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print inspection method and a print inspection apparatus for inspecting a printed matter for a print defect.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed for a print inspection method for inspecting a printed matter for a print defect.
For example, in Japanese Patent Application Laid-Open No. Hei 5-10880, an image is divided into small regions, and the maximum value or the sum of the difference data for each pixel is calculated and used for defect determination.

[0003]

However, in Japanese Patent Application Laid-Open No. Hei 5-10880, as described above, processing is performed on an image for each small area, but no detailed determination of a print defect is made.

Accordingly, an object of the present invention is to provide a print inspection method and a print inspection apparatus capable of performing a detailed inspection of the entire printed matter at high speed.

[0005]

According to the present invention, there is provided a print inspection method comprising: a step of storing a reference image of a printed material; a step of dividing the reference image into a plurality of regions; and a reference for each of the plurality of divided regions. Extracting a feature amount of each image, inputting an image of a printed matter to be inspected as an image to be inspected, temporarily storing the input image to be inspected, and converting the inputted image to be inspected. Dividing the reference image into the same number of regions as the number of divisions, extracting the feature amounts of the inspection image for each of the plurality of divided regions, and The feature amount and the extracted feature amount of the inspection image for each of the plurality of regions are compared for each corresponding region, and the region in which the difference between the two feature amounts exceeds a predetermined allowable value is determined. The method comprising the constant regions only for this difference in the determined both feature amount exceeds the allowable value,
Inspecting print defects in detail based on the stored reference image and the stored image to be inspected.

Further, the print inspection apparatus of the present invention has a first storage means for storing a reference image of a printed matter, a first division means for dividing the reference image into a plurality of areas, and a first division means. A first feature amount extraction unit for extracting a feature amount of a reference image for each area divided by the above, an image input unit for inputting an image of a printed matter to be inspected as an image to be inspected, and an image input unit A second storage unit that temporarily stores the inspected image that has been input, and a second dividing unit that divides the inspected image input by the image input unit into the same number of regions as the number of divisions of the first dividing unit. A second feature amount extraction unit for extracting a feature amount of the inspection image for each region divided by the second division unit; and a second feature amount extraction unit for each of the plurality of regions extracted by the first feature amount extraction unit. The feature amount of the reference image and the second feature amount A feature quantity of the inspection image of each of a plurality of regions extracted by means out compared for each corresponding region,
Comparing means for determining an area in which the difference between the two feature quantities exceeds a predetermined allowable value; and storing the first storage means only in the area in which the difference between the two feature quantities determined by the comparing means exceeds the allowable value. And an inspection unit for inspecting print defects in detail based on the reference image stored in the storage unit and the inspection image stored in the second storage unit.

Further, the print inspection apparatus of the present invention comprises a first dividing means for dividing a reference image of a printed material into a plurality of areas, and a feature amount of the reference image for each area divided by the first dividing means. A first feature amount extracting unit for extracting each of the extracted images; an image input unit for inputting an image of a printed matter to be inspected as an image to be inspected; and an image to be inspected input by the image input unit. A second dividing unit that divides the image into the same number of regions as the number of divisions, and a second unit that extracts a feature amount of the inspection image for each region divided by the second dividing unit.
A feature amount extracting unit, a feature amount of a reference image for each of a plurality of regions extracted by the first feature amount extracting unit, and a test image for each of a plurality of regions extracted by the second feature amount extracting unit Comparing means for each corresponding area, and comparing means for determining an area in which the difference between the two feature quantities exceeds a predetermined allowable value; and a plurality of means divided by the first and second dividing means. A plurality of first storage units provided corresponding to the respective regions and storing the reference images divided corresponding to the plurality of regions, respectively, and divided by the first and second division units A plurality of second storage means provided for each of the plurality of areas and storing the inspection image divided corresponding to each of the plurality of areas; and both feature amounts determined by the comparison means The image of the area where the difference of A plurality of inspection means for selecting from the reference image stored in the first storage means and the inspected image stored in the second storage means and inspecting the print defect in detail; And a result integrating means for integrating inspection results.

Further, the print inspection apparatus of the present invention has a first storage means for storing a reference image of a printed matter, a first division means for dividing the reference image into a plurality of regions, and a first division means. A first feature amount extraction unit for extracting a feature amount of a reference image for each area divided by the above, an image input unit for inputting an image of a printed matter to be inspected as an image to be inspected, and an image input unit A second dividing unit that divides the inspected image into the same number of regions as the number of divisions of the first dividing unit, and a feature amount of the inspected image for each region divided by the second dividing unit. A second feature extracting means for extracting, and the inspection image divided corresponding to the plurality of areas respectively provided in the plurality of areas divided by the first and second dividing means. Are stored respectively in the plurality of second Storage means; a feature quantity of a reference image for each of a plurality of areas extracted by the first feature quantity extraction means; and a feature quantity of an inspection image for each of a plurality of areas extracted by the second feature quantity extraction means. Are compared for each corresponding region, and a plurality of comparing means for determining an area in which the difference between the two feature amounts exceeds a predetermined allowable value, and the difference between the two feature amounts in the plurality of Selection means for selecting a second storage means corresponding to the area from the plurality of second storage means based on a determination result of the comparison means which has determined the excess area; and a second storage means selected by the selection means. A plurality of inspection means for inspecting print defects in detail based on an image to be inspected stored in a storage means and a reference image stored in the first storage means; and integration of inspection results of the plurality of inspection means. And a means for integrating results There.

According to the present invention, a detailed inspection of the entire printed material can be performed at high speed by performing a full inspection of the printed material for each small region and performing a detailed inspection only for the small region where an abnormality is recognized. Becomes

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described.

FIG. 1 shows the configuration of a print inspection apparatus according to the first embodiment. This print inspection apparatus includes an image input unit 101 as an image input unit, an image storage unit 102 as a storage unit, a reference image storage unit 103 as a storage unit, an area determination unit 104 as a division unit, a division unit, and feature amount extraction. Area selection unit 105 and accumulation unit 106 as means, global comparison unit 107 as comparison means, reference value determination unit 108 as feature amount extraction means, reference value storage unit 1
09, a position identification unit 110, a detailed comparison unit 111 as an inspection unit, and a result output unit 11 as a result output unit
2

Hereinafter, each part will be described in detail.

First, a method of storing a reference image of a printed matter P off-line and determining an area and a reference will be described.

Prior to the printing defect inspection process, a printed matter P (not shown) to be a defect-free reference image is conveyed by a conveying means (not shown) such as a conveyor belt in the printing machine A. Is illuminated by a light source that irradiates light to the surface. Light reflected from the surface of the printed material P is received by a photoelectric conversion unit (not shown) in the image input unit 101, and the entire surface is optically scanned to form image data of the entire surface.

As shown in FIG. 2, for example, the image input unit 101 includes a light source 200, a CCD type line sensor (photoelectric conversion unit) 201, an AGC (automatic gain control) circuit 202, A
/ D conversion circuit 203 and shading correction circuit 204.

That is, in the printing machine A, the light from the light source 200 is applied to the surface of the printed matter P which is conveyed in the direction of the arrow shown in the figure by a conveyor belt or the like (not shown). Light reflected from the surface of the printed matter P is transmitted to the line sensor 20.
The light is received by the first light receiving surface and photoelectrically converted. The output signal of the line sensor 201 is subjected to automatic gain control by the AGC circuit 202, and then digitized by the A / D conversion circuit 203.
After the digital signal is subjected to shading correction by the shading correction circuit 204, it is sent to the reference image storage unit 103 and the area determination unit 104.

In the reference image storage unit 103, the image input unit 1
The image input at 01 is stored as a reference image. As shown in FIG. 3, the reference image input by the image input unit 101 is formed and stored in the reference image storage unit 103, in which the upper bits of the address are associated with the Y coordinate and the lower bits of the address are associated with the X coordinate, as shown in FIG. Here, the X axis is the main scanning direction of the line sensor 201 in the image input unit 101, and the Y axis is the sub scanning direction. Xmax is the maximum value of the X coordinate of the printed matter P, and Ymax is the maximum value of the Y coordinate of the printed matter P.

The area determining unit 104 converts the input reference image into, for example, a no-print area, a complicated print area, and a flat print area by performing a process according to a procedure shown in a flowchart in FIG. Divide each.

Referring to FIG. 4, the input reference image is divided into m × n as shown in FIG. Also, assume that the image data in FIG. 3 is a (x, y), and the small area data in FIG. 5 is P (m, n) and P2 (m, n).

In steps 402 to 408, the density sum P of the small area is calculated from the image data a (x, y).
The sum of squares P2 (m, n) of (m, n) and the density of the small area is calculated. The calculated data P (m, n), P2 (m,
n) are sent to the reference value determination unit 108, respectively.

The reference value determination unit 108 performs processing in accordance with the procedure shown in the flowchart of FIG. 6, for example, so that the small area data P (m, n), P2 ( m, n), a reference value and a threshold value of the feature amount of the small area are created.

Referring to FIG. 6, the allowable value of the small area (m, n) is assumed to be th (m, n). As the reference value, P (m, n) is used as it is.

In steps 602 to 609, a variance value V (m, n) is calculated from the small area data P (m, n) and P2 (m, n), and the variance values V (m, n) and P The allowable value th (m, n) is determined from (m, n). The allowable value th (m, n) is given by th (m, n) = A × V (m,
n) −B × P (m, n) + C. here,
A, B, and C are arbitrary positive numbers.

By doing so, the tolerance increases as the variance increases and decreases as the density increases (closer to no printing). Therefore, the variance increases as the printing area becomes complicated, and the variance decreases as the printing area approaches the non-printing area.
From a region with a large tolerance to a complex print region, flat print region,
It is divided into a non-printing area. For example, when image data as shown in FIG. 3 is input, an allowable value th (m, n) is determined as shown in FIG.

The reference value P (m, n) thus determined
And the allowable value th (m, n) are sent to the reference value storage unit 109, respectively. The reference value storage unit 109 stores the reference value P (m, n) and the allowable value th (m, n) determined by the reference value determination unit 108, respectively.

The above is the method of storing the reference image of the printed matter P off-line and determining the area and the reference.

Next, a description will be given of a method of performing a print defect inspection process of the printed matter P online.

When the print defect inspection process is actually performed, the image input unit 101 is the same as in the case of off-line. The image of the printed matter to be inspected (image to be inspected) input by the image input unit 101 is sent to the image storage unit 102 and the area selection unit 105, respectively. Image storage unit 102
Temporarily stores the input inspection image.

The area selecting unit 105 performs processing according to a procedure shown in, for example, a flowchart shown in FIG.
The image is divided into small regions similar to the (m, n) small region determined in step 4, and the feature amount is calculated for each divided region.

Referring to FIG. 8, the input image to be inspected is divided into m × n as shown in FIG. Further, the input image data is represented by a1 (x,
y), the small area data is P1 (m, n).

In steps 802 to 808, the density sum P of the small area is calculated from the image data a1 (x, y).
1 (m, n) is calculated. Calculated concentration sum data P
1 (m, n) is sent to accumulating section 106. Accumulator 10
Reference numeral 6 stores, for each region, a feature amount (density sum P1 (m, n)) calculated for each region by the region selection unit 105.

The global comparing section 107 compares the value P1 (i, j) stored in the accumulating section 106 with the reference value P (i, j) stored in the reference value storing section 109, and if the difference is acceptable. This is for determining whether or not the value falls within a range of values. Each small area is individually configured, and each means is configured as shown in FIG. 9, for example.

In FIG. 9, a subtractor 901 calculates the difference between the density sum P1 (i, j) of a small area and a reference value P (i, j), and an absolute value calculator 902 calculates the absolute value. The comparator 903 compares the value with the allowable value th (i, j). If the allowable value is lower than the allowable value th (i, j), the area information (i, j) is not included in the allowable value range, and the area information (i, j) is determined as a defect candidate area. Output to 110.

The position specifying section 110 is a buffer for holding the area information sent from the global comparing section 107, and the area information sent is sequentially sent to the detailed comparing section 111. The detailed comparison unit 111 performs a detailed comparison only for the area determined to be a defect candidate area by the global comparison unit 107 by performing a process according to, for example, a flowchart shown in FIG.

Referring to FIG. 10, the reference image stored in the reference image storage unit 103 and the image to be inspected stored in the image storage unit 102 are transmitted from the position identification unit 110 in steps 1002 to 1008. By comparing only the obtained position information area, a difference calculation is performed between the pixels to generate a difference image, and the sum and variance of the pixel values are obtained for the difference image. Thereafter, in steps 1009 to 1013, the type of defect is determined by a combination of the calculated sum of pixel values and variance.

In the above description, comparison between pixels has been described as a detailed comparison, but comparison between differential images or comparison after frequency analysis may be performed.

The result obtained by the detail comparing unit 111 is sent to the result output unit 112 and fed back to the printing machine A. The result output unit 112 outputs each result sent from the general comparison unit 107 and the detailed comparison unit 111. This may be output to paper by a printer or the like,
Lighting of an LED may be used.

As described above, the printing state of the paper is analyzed from the reference image, the allowable value and the area that match the printing state are automatically determined, and after the global inspection is performed, the area of the candidate having the abnormality is determined. By performing only the detailed inspection, the entire surface of the printed matter P can be inspected at high speed and in detail.

As described above, according to the first embodiment, the texture is analyzed at the time of inputting the reference image, the reference value and the allowable value are determined for each small area, and the actual print defect inspection is performed. In some cases, a detailed inspection is performed only on a small area exceeding the allowable value, and a detailed inspection of the entire surface of the printed matter P can be performed at high speed.

Next, a second embodiment will be described.

FIG. 11 shows the configuration of a print inspection apparatus according to the second embodiment. In the second embodiment,
The configuration is the same as that of the first embodiment except that a data storage unit 1101 as a storage unit and a display confirmation unit 1102 are added to the above-described first embodiment. Therefore, only the data storage unit 1101 and the display confirmation unit 1102 will be described in detail.

The data storage unit 1101 stores the detailed comparison unit 11
The image data compared in step 1 is stored, and a large-capacity hard disk device or the like is used. The display confirmation unit 1102 displays the result of the inspection performed by the detail comparison unit 111 together with the image, and is used by the operator to confirm the result.
For example, it is configured as shown in FIG.

In FIG. 12, the image data stored in the data storage unit 1101 and the result of the detailed comparison unit 111 are displayed on a display unit 1202 such as a monitor via a display control unit 1201.
And is displayed on the display unit 1202. The operator checks the image and the result displayed on the display unit 1202,
If a mistake is made, a correction input is performed using the confirmation result input unit 1203 and output to the result output unit 112. The corrected input is stored in the data storage unit 1101.

As described above, the result of the detailed inspection is displayed on the screen, and the operator can confirm and correct the inspection, so that the inspection can be made more reliable, and the corrected result and the image are stored in association with each other. By doing so, it is possible to secure data for raising the level of the detailed comparison unit 111. In addition, by storing only the abnormal area, the capacity of the storage unit can be saved.

As described above, according to the second embodiment, the result of the detailed comparison is presented to the operator, and the operator makes a final decision. By storing the final images in association with each other, it is possible to secure data for upgrading the detail comparing unit 111. Also,
The data storage capacity can be reduced by selecting only the area where the abnormality is recognized and storing the data.

Next, a third embodiment will be described.

FIG. 13 shows the configuration of a print inspection apparatus according to the third embodiment. In the third embodiment,
In the first embodiment, the image storage unit 10
2. Instead of the reference image storage unit 103, the detailed comparison unit 111, and the result output unit 112, a plurality of detailed comparison units 130
The configuration is the same as that of the first embodiment except that the configuration uses 11 to 1301N and a result integration / output unit 1302. Therefore, the detailed comparison units 13011 to 1311
01N and the result integration / output unit 1302 will be described in detail.

Detailed comparison units 13011 to 1301N
Is a unit for performing parallel processing when comparing in detail an image of an area determined as a defect candidate by the global comparison unit 107, and corresponds to each of the small areas divided by the area determination unit 104, The same number as the small areas is provided.

Detailed comparison units 13011 to 1301N
Is a board to be inserted into, for example, a VME or PCI slot, and the configuration of the boards is all the same.
, A window setting unit 1401, a reference image storage unit 1402, an image storage unit 1403, a CPU 1404,
And a program storage unit 1405.

First, the printed matter P is stored in the reference image storage unit 1402.
A method for storing the reference image will be described.

The reference image input by the image input unit 101 is stored in each of the reference image storage units 1402 of the detailed comparison units 13011 to 1301N. At this time, each window value is set in each window setting unit 1401 of the detailed comparison units 13011 to 1301N. This window is the same as the small area used by the area determination unit 104 and the area selection unit 105. For example, as shown in FIG. 15, each of the small areas 1 to N from the upper left of the reference image is the one of the detailed comparison units 13011 to 1301N. Each of the reference image storage units 1402 stores the reference image.

Next, a method for performing a detailed comparison will be described.

The image to be inspected input by the image input unit 101 is stored in each image storage unit 1403 of each of the detailed comparison units 13011 to 1301N. At this time, each window value is set in each window setting unit 1401 of the detailed comparison units 13011 to 1301N. This window is the same as the small area used by the area determination unit 104 and the area selection unit 105. For example, as shown in FIG.
N is stored in each of the image storage units 1403 of the detailed comparison units 13011 to 1301N.

When the position information of the small area determined as a defect candidate by the global comparing section 107 is output to the position specifying section 110, the position specifying section 110 sends the information to the CPU 1404 of the unit storing the reference image of the small area. In response, a detailed comparison instruction is sent. The CPU 1404 that has received this instruction executes the program stored in the program storage unit 1405 to perform processing according to, for example, a procedure according to a flowchart shown in FIG.

Referring to FIG. 16, in steps 1602 to 1608, the sum of the difference image and the pixel value of the difference image is calculated, and the variance of the difference image is calculated. Thereafter, in steps 1609 to 1613, the type of defect is determined by a combination of the calculated sum of the pixel values and the variance, and the result is output to the result integration / output unit 1302.

The result integration / output unit 1302 integrates and outputs the results of the detailed comparison units 13011 to 1301N.

In the above description, comparison between pixels has been described as a detailed comparison, but comparison between differential images or comparison after frequency analysis may be performed.

As described above, by having a plurality of units for inspecting only the candidate area having an abnormality in detail, the entire surface of the printed matter P can be inspected at higher speed and in detail.

As described above, according to the third embodiment, a plurality of units for the detailed comparison part in the first embodiment are prepared, and each unit handles each small area. It is possible to inspect the entire surface of the printed matter P at higher speed.

Next, a fourth embodiment will be described.

FIG. 17 shows the configuration of a print inspection apparatus according to the fourth embodiment. In the fourth embodiment,
In the first embodiment, the image storage unit 10
2. Accumulation unit 106, global comparison unit 107, reference value storage unit 1
09, the detailed comparison unit 111, and the result output unit 112, a plurality of global comparison units 17011 to 1701N, a crossbar switch 1702, a detailed comparison unit 1703, a detailed comparison unit 1704, and a result integration / output unit 1705 are used. The other configuration is the same as that of the first embodiment. Therefore, the global comparison units 17011 to 1711
01N, crossbar switch 1702, detailed comparison unit 17
03, only the detailed comparison unit 1704 and the result integration / output unit 1705 will be described in detail.

Global comparison units 17011 to 1701N
Is a unit for extracting a defect candidate based on the approximate feature amount of an image, and is provided in the same number as the small regions corresponding to the small regions divided by the region determining unit 104, respectively.

Global comparison units 17011 to 1701N
Is, for example, a board to be inserted into a VME or PCI slot, and the configurations of the boards are all the same.
As shown in (1), it is composed of an accumulation unit 1801, a comparison unit 1802, and a memory 1803 as an image storage unit.

The accumulating section 1801 accumulates and stores the feature amounts calculated by the area selecting section 105. As a result, the global comparison units 17011 to 1701N accumulatively store the feature amounts of the respective small areas.

The comparing section 1802 compares the value of the accumulating section 1801 with the reference value determined by the reference value determining section 108, and makes a difference between the two values within the range of the allowable value determined by the reference value determining section 108. It is determined whether or not the area is within the range. If the area is not within the range of the allowable value, the position information of the area is sent to the position specifying unit 110. The comparing unit 1802 is configured, for example, as shown in FIG.

The crossbar switch 1702 is operated by the general comparison unit 1 based on a selection signal from the position specifying unit 110.
Selection operation is performed to select the memory 1803 corresponding to the area determined as the defect candidate area by the comparison sections 1802 of 701 1 to 1701 N, and the selected memory 1803 is selected from the detailed comparison section 1703 and the detail comparison section 1704 which are vacant. Connect to

Detail comparing section 1703 and detail comparing section 17
Numeral 04 is for inspecting in detail the small area which has been determined as a defect candidate by the global comparison units 17011 to 1701N, and is composed of, for example, a CPU 1901 and a program storage unit 1902 as shown in FIG. CPU1901
Executes a program stored in the program storage unit 1902 to perform processing according to, for example, a procedure according to a flowchart shown in FIG.

Referring to FIG. 20, in steps 2002 to 2008, the sum of the difference image and the pixel value of the difference image is calculated, and the variance of the difference image is calculated. Thereafter, in steps 2009 to 2013, the type of defect is determined by a combination of the calculated sum of the pixel values and the variance, and the result is output to the result integration / output unit 1705.

The result integration / output unit 1705 integrates the results of the detail comparison unit 1703 and the detail comparison unit 1704,
Output.

In the above description, comparison between pixels has been described as a detailed comparison, but comparison between differential images or comparison after frequency analysis may be performed.

As described above, by having a plurality of global comparison units, and connecting only a plurality of units to be inspected in detail by using the crossbar switch only in a candidate area having an abnormality, the entire surface of the printed matter P can be further speeded up. It can be inspected in detail.

As described above, according to the fourth embodiment, a plurality of units of the global comparison part in the first embodiment are prepared, and data of each small area is stored in each unit. By switching and connecting to a plurality of detailed comparison units using a crossbar switch, it is possible to inspect the entire surface of the printed matter P at higher speed.

[0074]

As described above in detail, according to the present invention, it is possible to provide a print inspection method and a print inspection apparatus capable of performing a detailed inspection of the entire printed matter at high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a print inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a configuration of an image input unit.

FIG. 3 is a conceptual diagram illustrating data stored in a reference image storage unit.

FIG. 4 is a flowchart illustrating a processing procedure of an area determining unit.

FIG. 5 is a conceptual diagram illustrating image area division.

FIG. 6 is a flowchart illustrating a processing procedure of a reference value determining unit.

FIG. 7 is a conceptual diagram illustrating image area division.

FIG. 8 is a flowchart illustrating a processing procedure of an area selection unit.

FIG. 9 is a block diagram schematically showing a configuration of a general comparison unit.

FIG. 10 is a flowchart illustrating a processing procedure of a detail comparing unit.

FIG. 11 is a block diagram schematically showing a configuration of a print inspection apparatus according to a second embodiment of the present invention.

FIG. 12 is a block diagram schematically showing a configuration of a display confirmation unit.

FIG. 13 is a block diagram schematically showing a configuration of a print inspection apparatus according to a third embodiment of the present invention.

FIG. 14 is a block diagram schematically showing a configuration of a detailed comparison unit.

FIG. 15 is a conceptual diagram of a stored image in a detailed comparison unit.

FIG. 16 is a flowchart illustrating a processing procedure executed by a CPU of the detailed comparison unit.

FIG. 17 is a block diagram schematically showing a configuration of a print inspection apparatus according to a fourth embodiment of the present invention.

FIG. 18 is a block diagram schematically showing a configuration of a global comparison unit.

FIG. 19 is a block diagram schematically showing a configuration of a detail comparing unit.

FIG. 20 is a flowchart illustrating a processing procedure executed by a CPU of a detail comparing unit.

[Explanation of symbols]

101 image input unit (image input unit), 102 image storage unit (storage unit), 103 reference image storage unit (storage unit), 104 area determination unit (division unit), 105
... Area selection unit (division unit, feature amount extraction unit), 106
... Accumulation unit, 107 ... Overall comparison unit (comparison means), 10
8... Reference value determination unit (feature amount extraction unit), 109... Reference value storage unit, 111.
2 ... result output unit (result output means), 1101 ... data storage unit (storage means), 1102 ... display confirmation unit, 12
01 ... display control unit, 1202 ... display unit, 1203 ...
... Confirmation result input unit, 13011 to 1301N ... Detailed comparison unit, 1302 ... Result integration / output unit, 1402 ...
... Reference image storage unit (storage unit), 1403... Image storage unit (storage unit), 1404.
701N: global comparison unit, 1702: crossbar switch, 1703, 1704: detailed comparison unit (inspection means), 1705: result integration / output unit, 1801 ...
Accumulator, 1802... Comparator, 1803.
901: CPU, P: Printed matter.

Claims (9)

[Claims] A step of storing a reference image of a printed matter; a step of dividing the reference image into a plurality of regions; a step of extracting a feature amount of the reference image for each of the plurality of divided regions; Inputting an image of the target printed matter as an image to be inspected; temporarily storing the input image to be inspected; dividing the input image to be inspected into the same number of areas as the number of divisions of the reference image Extracting each of the feature amounts of the inspection image for each of the plurality of divided regions; and extracting the feature amounts of the reference image for each of the extracted plurality of regions and each of the extracted plurality of regions. Comparing the feature amount of the image to be inspected with each corresponding region to determine a region where the difference between the two feature amounts exceeds a predetermined allowable value; A step of inspecting print defects in detail, based on the stored reference image and the stored image to be inspected, only for an area in which the difference between the feature amounts exceeds an allowable value. Inspection methods. A first storage unit for storing a reference image of a printed matter; a first division unit for dividing the reference image into a plurality of regions; and a reference for each of the regions divided by the first division unit. A first feature amount extracting unit for extracting a feature amount of an image, an image input unit for inputting an image of a printed material to be inspected as an image to be inspected, and temporarily storing the image to be inspected input by the image input unit A second storage unit that divides the image to be inspected input by the image input unit into the same number of regions as the number of divisions of the first division unit; A second feature value extraction unit for extracting a feature value of the inspection image for each of the divided regions; a feature value of the reference image for each of the plurality of regions extracted by the first feature value extraction unit; Multiple extracted by the feature extraction means Comparing means for comparing the feature amount of the image to be inspected for each area for each corresponding area to determine a region in which the difference between the two feature amounts exceeds a predetermined allowable value; and both features determined by the comparing means. For only the area where the difference in the amount exceeds the allowable value, the print defect is inspected in detail based on the reference image stored in the first storage unit and the inspection image stored in the second storage unit. A printing inspection apparatus, comprising: inspection means. 3. The print inspection apparatus according to claim 2, further comprising a determination unit configured to determine a type of a print defect based on an inspection result of the inspection unit. 4. The print inspection apparatus according to claim 2, further comprising a result output unit that outputs an inspection result of the inspection unit. 5. An image in a region where the difference between the two feature values determined by the comparing means exceeds an allowable value is selected from the images to be inspected stored in the second storing means, and the selected image is selected. Third storage means for storing; display means for displaying the image stored in the third storage means and the inspection result of the inspection means; and confirming the display contents of the display means and inputting the confirmation result. 3. The print inspection apparatus according to claim 2, further comprising: a confirmation result input unit; and a result output unit that outputs an inspection result of the inspection unit based on the confirmation result input by the confirmation result input unit. . 6. A fourth memory for associating the input check result with the corrected image when a check result for correcting the check result of the check means is input by the check result input means. The print inspection apparatus according to claim 5, further comprising a storage unit. 7. A first dividing unit for dividing a reference image of a printed matter into a plurality of regions, and a first characteristic amount for extracting a characteristic amount of the reference image for each region divided by the first dividing unit. Extracting means; image input means for inputting an image of a printed matter to be inspected as an image to be inspected; dividing the image to be inspected inputted by the image input means into regions equal in number to the number of divisions of the first dividing means A second dividing means for extracting, a second characteristic amount extracting means for respectively extracting a characteristic amount of the inspection image for each area divided by the second dividing means, and an extracting means for extracting the characteristic amount. The feature amount of the reference image for each of the plurality of regions and the feature amount of the image to be inspected for each of the plurality of regions extracted by the second feature amount extracting means are compared for each corresponding region. If the difference exceeds a predetermined tolerance Comparing means for judging, and a plurality of areas divided by the first and second dividing means are provided, and the reference images divided corresponding to the plurality of areas are stored, respectively. Multiple first
And a plurality of storage units each provided corresponding to a plurality of regions divided by the first and second division units, and storing the inspection image divided corresponding to the plurality of regions. A reference image stored in the first storage unit and an image of an area in which the difference between the two feature amounts determined by the comparison unit exceeds an allowable value; and the second storage unit. A plurality of inspection means for selecting from the images to be inspected stored in and inspecting print defects in detail, and a result integration means for integrating respective inspection results of the plurality of inspection means. Printing inspection equipment. 8. The plurality of inspection units are provided by the number corresponding to the plurality of first and second storage units, respectively, and the reference image and the second image stored in the first storage unit are provided. The detailed inspection of the print defect is performed in parallel based on the image to be inspected stored in the storage unit, and the inspection corresponding to the area where the difference between the two characteristic amounts determined by the comparison unit exceeds the allowable value. 8. The print inspection apparatus according to claim 7, further comprising a selection unit for selecting a unit from the plurality of inspection units. 9. A first storage unit for storing a reference image of a printed matter; a first division unit for dividing the reference image into a plurality of regions; and a reference for each region divided by the first division unit. A first feature amount extraction unit for extracting a feature amount of an image, an image input unit for inputting an image of a printed matter to be inspected as an image to be inspected, and an image to be inspected input by the image input unit. A second dividing unit for dividing into the same number of regions as the number of divisions of the first dividing unit, and a second feature amount extracting unit for extracting a feature amount of the image to be inspected for each region divided by the second dividing unit Means, provided in correspondence with the plurality of areas divided by the first and second dividing means, respectively, and a plurality of the plurality of areas in which the inspection images divided corresponding to the plurality of areas are respectively stored. Storage means, and the first feature Comparing the feature amount of the reference image for each of the plurality of regions extracted by the extraction unit with the feature amount of the image to be inspected for each of the plurality of regions extracted by the second feature amount extraction unit for each corresponding region; A plurality of comparing means for determining an area where the difference between the two feature quantities exceeds a predetermined allowable value; and a comparing means for determining an area where the difference between the two feature quantities exceeds the allowable value among the plurality of comparing means. Selecting means for selecting a second storage means corresponding to the area from the plurality of second storage means based on the result; and an image to be inspected stored in the second storage means selected by the selection means. And a plurality of inspection means for inspecting print defects in detail based on the reference image stored in the first storage means, and a result integration means for integrating respective inspection results of the plurality of inspection means. Printing characterized by査 apparatus.