JP2023129158A - Image processing device and computer program - Google Patents

Abstract

To suppress a code image in a printed image from becoming unclear.SOLUTION: An image processing device performs color conversion processing on target image data to generate converted image data, and performs halftone processing to generate dot data. The converted image data includes first component image data corresponding to a first color material having the color of a code image, and the dot data includes first component dot data corresponding to the first color material. The image processing device generates code binary data by performing specific binarization processing which is different from the halftone processing on partial data indicating the code area of the first component image data, generates code binary data, replaces partial data indicating the code area of the first component dot data with code binary data, generate replaced first component dot data, and generate print data including the replaced first component dot data.SELECTED DRAWING: Figure 6

Description

The present specification relates to image processing using image data generated using an image sensor.

The image processing apparatus disclosed in Patent Document 1 executes printing using image data obtained by reading a document using a scanner. At this time, if a two-dimensional code is included in the image represented by the image data, the two-dimensional code is decoded to obtain the information represented by the two-dimensional code. The two-dimensional code is erased from the image, and a two-dimensional code regenerated by encoding the information represented by the two-dimensional code is synthesized in the erased portion. It is said that this makes it possible to suppress deterioration of the image quality of the two-dimensional code in the printed image.

Japanese Patent Application Publication No. 2007-174317

However, with the above technology, if there is an error in decoding the two-dimensional code, an incorrect image different from the original may be printed. Further, with the above technology, if an image includes a two-dimensional code whose decoding algorithm is unknown, the two-dimensional code cannot be regenerated.

This specification discloses a new technique that can prevent a code image in a printed image from becoming unclear when printing using image data generated using an image sensor.

The technology disclosed in this specification has been made to solve at least part of the above-mentioned problems, and can be realized as the following application examples.

[Application Example 1] An image processing device, comprising: an image acquisition unit that acquires target image data indicating a target image including a code image and generated using an image sensor, and the target image data. A color conversion unit that generates converted image data by performing a color conversion process on the image, wherein the converted image data includes one or more component image data corresponding to one or more color materials used for printing. and the one or more component image data includes first component image data corresponding to a first color material having the color of the code image, and the color conversion unit performs halftone processing on the converted image data. a halftone processing unit that generates dot data indicating a dot formation state by performing The component dot data is processed by the halftone processing unit including first component dot data corresponding to the first color material, and partial data indicating a code area including the code image among the first component image data. a binarization processing unit that generates code binary data by executing a specific binarization process different from the halftone process, the specific binarization process converting a value of a pixel of interest to the pixel of interest; generates print data using the binarization processing section, the dot data, and the code binary data, which is a process of binarization using a specific threshold value without depending on the values of different pixels. a generation unit, the generation unit replaces partial data indicating the code region in the first component dot data with the code binary data to generate replaced first component dot data; An image processing device that generates the print data including the replaced first component dot data.

According to the above configuration, the print data is obtained by replacing the partial dot data indicating the code area including the code image with the code binary image among the specific component dot data corresponding to the specific color material having the color of the code image. Contains replaced specific component dot data. A code binary image is a system that sets the value of a pixel of interest to a specific threshold value for partial image data indicating a code image among specific component image data corresponding to a specific color material without depending on the value of a pixel different from the pixel of interest. It is generated by executing a specific binarization process to binarize using . In the image shown by the code binary data, the image showing the code image is less likely to become unclear. Therefore, when printing using image data generated using an image sensor, it is possible to prevent the code image in the print image from becoming unclear.

Note that the technology disclosed in this specification can be realized in various forms, such as printing devices, printing methods, image processing methods, functions of these devices, or computer programs for realizing the above methods. , a recording medium on which the computer program is recorded, etc.

FIG. 1 is a block diagram showing the configuration of a multifunction device 200 that is an example of an image processing device. 2 is a flowchart of image processing in the first embodiment. The figure which shows an example of scan image SI shown by scan data. Flowchart of background color analysis processing. The figure which shows an example of a component image. 1 is a flowchart of code binarization processing according to the first embodiment. An explanatory diagram of code binarization processing. The figure which shows an example of a substituted C component dot image. The figure which shows an example of a print image. Flowchart of image processing according to the second embodiment. 10 is a flowchart of background color analysis processing according to the second embodiment. 12 is a flowchart of code binarization processing according to the second embodiment. Flowchart of image processing according to the third embodiment. 12 is a flowchart of code binarization processing according to the third embodiment.

A. First example:
A-1. Configuration of multifunction device 200 An embodiment will be described based on an example. FIG. 1 is a block diagram showing the configuration of a multifunction device 200, which is an example of an image processing device. The multifunction device 200 includes a CPU 210 that is a processor that controls an image processing device, a volatile storage device 220 such as a DRAM, a nonvolatile storage device 230 such as a flash memory or a hard disk drive, and a display unit 240 such as a liquid crystal display. An operation unit 250 including a touch panel and buttons superimposed on a liquid crystal display, an interface (communication IF) 270 for communicating with an external device such as a user's terminal device 100, a printing execution unit 280, and a reading execution unit 290. , is equipped with.

The reading execution unit 290 generates scan data by optically reading a document using a one-dimensional image sensor under the control of the CPU 210 . The print execution unit 280 is an electrophotographic print execution unit. The print execution unit 280 uses multiple types of toner, specifically, cyan (C), magenta (M), yellow (Y), and black (K) toners as color materials under the control of the CPU 210. Print an image on print media such as paper. Specifically, the print execution unit 280 exposes the photosensitive drum to form an electrostatic latent image, and attaches toner to the electrostatic latent image to form a toner image. The printing execution unit 280 transfers the toner image formed on the photosensitive drum onto paper.

The volatile storage device 220 provides a buffer area that temporarily stores various intermediate data generated when the CPU 210 performs processing. A computer program PG is stored in the nonvolatile storage device 230. The computer program PG is a control program that causes the CPU 210 to control the multifunction device 200. In this embodiment, the computer program PG is provided in a form that is stored in advance in the nonvolatile storage device 230 when the multifunction device 200 is manufactured. Alternatively, the computer program PG may be provided in the form of being downloaded from a server, or may be provided in the form of being stored on a DVD-ROM or the like. The CPU 210 can perform image processing, which will be described later, by executing the computer program PG.

A-2. Image Processing FIG. 2 is a flowchart of image processing in the first embodiment. This image processing is executed, for example, when the user places a document on the document table of the reading execution section 290 and inputs a copy execution instruction. This image processing involves acquiring scan data generated by reading a document using the reading execution unit 290, and using the scan data to generate print data representing the document, thereby making a so-called copy of the document. This is the process to achieve this.

In S10, the CPU 210 generates scan data by using the reading execution unit 290 to read a document placed on the document table by the user. The manuscript is, for example, a printed matter on which an image is printed by the multifunction device 200 or a printer (not shown). The generated scan data is stored in a buffer area of volatile storage device 220 (FIG. 1). The scan data includes values of a plurality of pixels, and each of the values of the plurality of pixels represents the color of the pixel as a color value in the RGB color system (also referred to as an RGB value). That is, the scan data is RGB image data. The RGB value of one pixel includes, for example, the values of three color components: red (R), green (G), and blue (B) (hereinafter also referred to as R value, G value, and B value). I'm here. In this embodiment, the number of gradations for each component value is 256 gradations.

The scan data, which is RGB image data, includes three component image data (R component image data, G component image data, and B component image data) corresponding to the three color components that make up the RGB color system. You can say that. Each component image data is image data whose pixel value is the value of one type of color component.

FIG. 3 is a diagram illustrating an example of a scan image SI represented by scan data. Scan image SI includes multiple pixels. The plurality of pixels are arranged in a matrix along a first direction D1 in FIG. 3 and a second direction D2 orthogonal to the first direction D1.

The scanned image SI in FIG. 3 includes a first background BG1 showing the ground color of the paper of the original, a second background BG2 showing the solid area printed on the original, and a code image CI1 which is an object printed on the original. , CI2, and a plurality of texts TX. In the example of FIG. 3, the color of the first background BG1 (also referred to as the first background color) is a bright color and a chromatic color (for example, bright blue). The color of the second background BG2 (also referred to as a second background color) is a dark color and a chromatic color (for example, dark green).

Code images CI1 and CI2 are images showing a one-dimensional code (for example, a barcode) or a two-dimensional code (for example, a QR code (registered trademark)). The color of code images CI1 and CI2 (also referred to as code color) is black. The color of the plurality of texts TX is black.

In S20, the CPU 210 executes reading gamma correction processing on the scan data. The reading gamma correction process is a known process that uses a predetermined gamma curve to correct the value of each pixel of the three component image data forming the scan data. As a result, the brightness of the scan image SI is adjusted, and the appearance of the scan image SI is improved. Hereinafter, scan data that has undergone read gamma correction processing will be simply referred to as scan data, and an image represented by the scan data that has undergone read gamma correction processing will simply be referred to as a scan image.

In S25, the CPU 210 executes code area specifying processing on the scan data. The code area specifying process is a process of specifying a code area including the code image when the code image exists in the scan image SI. In the example of FIG. 3, a first code area CA1 including the first code image CI1 and a second code area CA2 including the second code image CI2 are specified. Code regions CA1 and CA2 are specified to include quiet zone QZ. The quiet zone QZ is a margin provided at the left and right ends of a one-dimensional code, and at the top, bottom, left, and right ends of a two-dimensional code, and is stipulated to be provided in the standards for one-dimensional codes and two-dimensional codes. There is. A known method used when reading a code image is used to identify the code region. For example, the code area including the QR code (registered trademark) is identified by detecting finder patterns placed at three corners of the QR code (registered trademark).

In S30, the CPU 210 performs background color analysis processing on data indicating the code area specified in the scan image SI. The background color analysis process is a process that identifies the background color of the code area and performs a predetermined determination on the background color.

FIG. 4 is a flowchart of background color analysis processing. In S104, the CPU 210 determines whether a code area has been specified in the scan image SI in the code area specifying process described above. If the code region is not specified (S104: NO), the CPU 210 ends the background color analysis process. If a code region has been identified (S104: YES), in S106, the CPU 210 selects one code region of interest from among the one or more identified code regions. In the example of FIG. 3, one code area of interest is selected from two code areas CA1 and CA2.

In S108, the CPU 210 classifies the plurality of pixels in the code area of interest into code constituent pixels and background pixels. The code constituent pixels are pixels that constitute a code image (eg, first code image CI1) within the code area of interest (eg, first code area CA1). The background pixel is a pixel that constitutes the background within the code area of interest. Specifically, the CPU 210 classifies pixels having color values within a predetermined black pixel range as code constituent pixels, and classifies pixels having color values outside the black pixel range as background pixels. Execute value processing. The black pixel range is a range of RGB values indicating black, and is a range of RGB values including (R, G, B) = (0, 0, 0). The black pixel range is, for example, a range that satisfies 0≦R≦20, 0≦G≦20, and 0≦B≦20.

In S110, the CPU 210 identifies the background color of the code area of interest using the color values (RGB values) of a plurality of background pixels within the code area of interest. In this embodiment, the average value of the color values of a plurality of background pixels is calculated as the color value indicating the background color. Note that as the color value indicating the background color, a statistical value different from the average value of the color values of background pixels, such as a median value or a mode value, may be used.

In S112, the CPU 210 calculates the saturation Sb and brightness Vb of the background color of the code area of interest. For example, if the color values (RGB values) of the background color are (Rb, Gb, Bb), the saturation Sb is calculated using the following formula (1), and the brightness Vb is calculated using the following formula (2). Calculated.

Sb=max(Rb, Gb, Bb)-min(Rb, Gb, Bb)...(1)
Vb=max(Rb, Gb, Bb)...(2)

max(Rb, Gb, Bb) means the maximum value of the three component values Rb, Gb, Bb. min(Rb, Gb, Bb) means the minimum value of the three component values Rb, Gb, Bb. Note that the above equations (1) and (2) are just examples, and other equations for calculating saturation and brightness may be employed.

In S114, the CPU 210 determines whether the saturation Sb of the background color is less than or equal to a predetermined saturation threshold THs. If the saturation Sb of the background color is less than or equal to the saturation threshold THs (S114: YES), the CPU 210 determines in S116 that the background color of the code area of interest is an achromatic color. If the saturation Sb of the background color is greater than the saturation threshold THs (S114: NO), the CPU 210 determines in S118 that the background color of the code area of interest is a chromatic color.

In S120, the CPU 210 determines whether the brightness Vb of the background color is less than or equal to a predetermined brightness threshold THv. If the brightness Vb of the background color is less than or equal to the brightness threshold THv (S120: YES), the CPU 210 determines in S122 that the background color of the code area of interest is dark. If the saturation Sb of the background color is greater than the saturation threshold THs (S120: NO), the CPU 210 determines in S124 that the background color of the code area of interest is a bright color.

In S126, the CPU 210 determines whether all code areas have been processed. If there is an unprocessed code area (S126: YES), the CPU 210 returns the process to S106. If all code regions have been processed (S126: NO), the CPU 210 ends the background color analysis process.

When the background color analysis process is completed, in S40 of FIG. 2, the CPU 210 executes a color conversion process on the scan data. The color conversion process is a process of converting scan data, which is RGB image data, into CMYK image data. CMYK image data is image data that indicates the color of each pixel using CMYK values. The CMYK values are color values of a color system (also called CMYK color system) that has multiple components (C, M, Y, and K components) corresponding to multiple toners used for printing. The color conversion process of this embodiment is executed with reference to a color conversion table (not shown). The color conversion table is, for example, a known lookup table that defines the correspondence between RGB values and CMYK values.

CMYK image data includes four component image data (C component image data, M component image data, Y component image data, K component image data) corresponding to the four color components that make up the CMYK color system. I can say that there is. Each component image data is image data whose pixel value is the value of one type of color component.

FIG. 5 is a diagram showing an example of a component image. The K component image KI in FIG. 5(A) is an image indicated by K component image data. The C component image CI in FIG. 5(B) is an image indicated by C component image data. Illustrations of an M component image represented by M component image data and a Y component image represented by Y component image data are omitted.

In the K component image KI, parts expressed in black (for example, code images CI1k, CI2k, and text TXk) are black parts. In the K component image KI, the hatched portion (for example, second background BG2k) is a portion that is lighter than black and has a K component greater than 0. In the K component image KI, a white portion (for example, the first background BG1k) is a portion where the K component is 0.

The code areas CA1k and CA1k of the K component image KI and the code areas CA1c and CA2c of the C component image CI are areas corresponding to the code areas CA1 and CA2 of the scan image SI (FIG. 3), respectively. Since the code images CI1 and CI2 and the text TX of the scan image SI are black, the K component image KI includes the code images CI1k and CI2k and the text TXk corresponding to these. The C component image CIc, the M component image, and the Y component image do not include a code image or text.

The background BG1k of the K component image KI and the background BG1c of the C component image CI are regions corresponding to the first background BG1 of the scan image SI (FIG. 3), respectively. Since the first background BG1 of the scan image SI has a bright color, the K component of the first background BG1k of the K component image KI is 0. Furthermore, since the first background BG1 of the scan image SI is also a chromatic color, the first background of at least one component image of CMY has components. In the example of FIG. 5(B), the first background BG1c of the C component image CI has a C component.

The background BG2k of the K component image KI and the background BG2c of the C component image CI are regions corresponding to the second background BG2 of the scan image SI (FIG. 3), respectively. Since the second background BG2 of the scan image SI has a dark color, the second background BG2k of the K component image KI has a K component greater than 0. Moreover, since the second background BG2 of the scan image SI is also a chromatic color, the second background of at least one component image of CMY has components. In the example of FIG. 5(B), the second background BG2c of the C component image CI has a C component.

In S45 of FIG. 2, the CPU 210 executes recording gamma correction processing on the CMYK image data. Recording gamma correction processing is a known process that uses a gamma curve to correct the value of each pixel of four component image data forming CMYK image data. The gamma curve is determined for each print execution unit 280 so as to correct density variations for each print execution unit 280 . For this reason, density variations are corrected by recording gamma correction processing so that the density of each color of the printed image becomes an appropriate density. In the following, the CMYK image data that has undergone recording gamma correction processing will be simply referred to as CMYK image data. Furthermore, the K component image data that has undergone recording gamma correction processing is simply referred to as K component image data, and the image represented by the K component image data that has undergone recording gamma correction processing is simply referred to as a K component image. The same applies to each CMY component image data and each component image.

In S50, the CPU 210 performs halftone processing on the CMYK image data to generate dot data indicating the dot formation state for each CMYK component and for each pixel. In this embodiment, there are two types of dot formation states: dots present and dots absent. In this embodiment, in image processing (so-called copy processing) that performs printing using scan data, in order to suppress moiré (interference fringes) that cause image quality deterioration, halftone processing includes error diffusion processing according to the error diffusion method. has been adopted. When a dither method is employed in copy processing, moiré tends to occur due to the periodicity of the dither matrix.

The dot data includes four component dot data (C component dot data, M component dot data, Y component dot data, K component dot data) corresponding to the four color components that make up the CMYK color system. You can say that. Each component dot data is binary image data that indicates the above-described two states of dot presence and dot absence for each pixel.

5(A) can also be said to be an image showing a K component dot image KDI shown by K component dot data, and FIG. 5(B) is an image showing a C component dot image CDI shown by C component dot data. It can also be said that Illustrations of the M component dot image indicated by the M component dot data and the Y component dot image indicated by the Y component dot data are omitted.

In the K component dot image KDI, parts expressed in black (for example, code images CI1k, CI2k, and text TXk) are parts where K toner dots (hereinafter also referred to as K dots) are densely formed. In the K component dot image KDI, the hatched portion (for example, second background BG2k) is a portion where K dots are formed in a sparser and dispersed manner than in the portion expressed in black. In the K component dot image KDI, a white portion (for example, the first background BG1k) is a portion where no K dots are formed. In the C component dot image CDI, hatched areas (for example, first background BG1c, second background BG2c) are areas where C toner dots (hereinafter also referred to as C dots) are formed in a dispersed manner.

In S55, the CPU 210 executes code binarization processing. The code binarization process is a process of binarizing the image within the code area by a process different from the halftone process of S50.

FIG. 6 is a flowchart of code binarization processing in the first embodiment. In S204, the CPU 210 determines whether a code area has been specified in the scan image SI in the code area specifying process described above. If the code region is not specified (S204: NO), the CPU 210 ends the code binarization process. If a code region is identified (S204: YES), in S206, the CPU 210 selects one code region of interest from among the one or more identified code regions. In the example of FIG. 3, one code area of interest is selected from two code areas CA1 and CA2.

In S208, the CPU 210 generates simple binary data of the code area of interest. Specifically, the CPU 210 executes simple binarization processing on partial data indicating the code area of interest among the K component image data. The simple binarization process is a process of binarizing the value of the K component of each pixel to be processed using one threshold value THb common to all pixels to be processed. The threshold value THb is, for example, 128 when the value of the K component takes a value from 0 to 255. In this way, in simple binarization processing, unlike error diffusion processing, the value of the K component of the pixel of interest does not depend on the values of pixels different from the pixel of interest (for example, pixels surrounding the pixel of interest). Binarization is performed using a specific threshold value THb.

FIG. 7 is an explanatory diagram of code binarization processing. FIG. 7A shows an example of a simple binary image represented by simple binary data. Simple binary data indicating the simple binary image BA1 is generated when the code area of interest is the first code area CA1 in FIG. 3. Simple binary data indicating simple binary image BA2 is generated when the code area of interest is second code area CA2 in FIG. 3. These simple binary data are generated by performing simple binarization processing on partial data indicating the code areas CA1k and CA2k of the K component image KI in FIG. 5(A), respectively. Simple binary images BA1 and BA2 indicate code images CI1b and CI2b corresponding to code images CI1 and CI2 of scanned image SI in FIG. 3, respectively.

In S210, the CPU 210 replaces the data in the code area of interest in the K component dot data with the simple binary data generated in S208. When the code area of interest is the first code area CA1 (FIG. 3), the partial data indicating the first code area CA1k (FIG. 5(A)) of the K component dot data is as shown in FIG. 7(A). It is replaced with simple binary data indicating simple binary image BA1. When the code area of interest is the second code area CA2 (FIG. 3), the partial data indicating the second code area CA2k of the K component dot data indicates the simple binary image BA2 of FIG. 7(B). Replaced with simple binary data. As a result, substituted K component dot data is generated.

FIG. 7B shows a replaced K component dot image KDIr indicated by replaced K component dot data. The image in the first code area CA1k of the replaced K component dot image KDIr in FIG. 7(B) is the simple binary image BA1 in FIG. 7(A). The image in the first code area CA1k of the replaced K component dot image KDIr is the simple binary image BA2 in FIG. 7(B). The image in the area different from the code areas CA1k and CA2k of the replaced K component dot image KDIr is the same as the image in the corresponding area of the K component dot image KDI in FIG. 5.

In S212, the CPU 210 determines whether the current print mode is the toner save mode. In this embodiment, either the normal mode or the toner save mode is selected as the print mode for copy processing. The print mode is selected based on a user's instruction input via the operation unit 250, for example. The toner save mode is a print mode that consumes less toner than the normal mode. For example, in toner save mode, printing is performed in overall lighter colors than in normal mode.

If the print mode is the toner save mode (S212: YES), the CPU 210 advances the process to S218. If the print mode is the normal mode (S212: NO), the CPU 210 advances the process to S214.

In S214, the CPU 210 determines whether the background color of the code area of interest is an achromatic color or a chromatic color based on the result of the background color analysis process (FIG. 4). As described above, the background color of the first code area CA1 (FIG. 3) is determined to be bright and chromatic in the background color analysis process. For this reason, when the code area of interest is the first code area CA1, it is determined in this step that the background color is a chromatic color. As described above, the background color of the second code area CA2 is determined to be dark and chromatic in the background color analysis process. For this reason, when the code area of interest is the second code area CA2 (FIG. 3), it is determined in this step that the background color is a chromatic color.

If the background color of the code area of interest is achromatic (S214: YES), the CPU 210 advances the process to S218. If the background color of the code area of interest is a chromatic color (S214: NO), the CPU 210 advances the process to S216.

In S216, the CPU 210 determines whether the background color of the code area of interest is dark or light based on the result of the background color analysis process (FIG. 4). When the code area of interest is the first code area CA1 (FIG. 3), the background color of the first code area CA1 is determined to be bright and chromatic in the background color analysis process, as described above. Therefore, in this step, the background color is determined to be light. When the code area of interest is the second code area CA2 (FIG. 3), the background color of the second code area CA2 is determined to be dark and chromatic in the background color analysis process, as described above. Therefore, in this step, the background color is determined to be dark.

If the background color of the code area of interest is dark (S214: YES), the CPU 210 advances the process to S218. If the background color of the code area of interest is bright (S214: NO), the CPU 210 advances the process to S220.

In S218, the CPU 210 replaces the data in the code area of interest among the CMYK component dot data with data indicating that no dots will be formed (data indicating no dots). As a result, replaced C component dot data, replaced M component dot data, and replaced Y component dot data are generated.

FIG. 8 is a diagram showing an example of a replaced C component dot image indicated by replaced C component dot data. FIG. 8A shows a replaced C component dot image CDIr generated in the normal mode. FIG. 8B shows a replaced C component dot image CDIs generated in the toner save mode. Illustrations of a replaced M component dot image indicated by replaced M component dot data and a replaced Y component dot image indicated by replaced Y component dot data are omitted.

As described above, the background color of the first code area CA1 is determined to be a bright color and a chromatic color in the background color analysis process. For this reason, when the code area of interest is the first code area CA1 (FIG. 3), only when the print mode is the toner save mode, in this step, the first code area of each CMY component dot image is The data is replaced with data indicating no dots. For example, in the normal mode example of FIG. 8A, in the replaced C component dot image CDIr, the code area CA1c is not an image without dots. In the example of the toner save mode shown in FIG. 8B, in the replaced C component dot image CDIs, the code area CA1c is an image without dots.

As described above, the background color of the second code area CA2 is determined to be dark and chromatic in the background color analysis process. For this reason, when the code area of interest is the second code area CA2 (FIG. 3), whether the print mode is toner save mode or normal mode, each CMY component dot image is printed in this step. The data in the first code area is replaced with data indicating no dots. For example, in both the examples shown in FIGS. 8A and 8B, in the replaced C component dot images CDIr and CDIs, the code area CA2c is an image without dots.

In S220, the CPU 210 determines whether all code areas have been processed. If there is an unprocessed code area (S220: YES), the CPU 210 returns the process to S206. If all code regions have been processed (S220: NO), the CPU 210 ends the code binarization process.

When the code binarization process is completed, in S60 of FIG. 2, the CPU 210 generates print data including the code binarized dot data. Specifically, print data is generated by adding a print command or the like to dot data. In S65, the CPU 210 outputs the generated print data to the print execution unit 280. When the print execution unit 280 receives the print data, it uses the print data to print a print image indicated by the dot data on paper.

FIG. 9 is a diagram showing an example of a printed image. FIG. 9A shows a print image PIn in the normal mode. FIG. 9B shows a print image PIs in the toner save mode. In the print images PIn and PIs, the code images CI1b and CI2b within the images are images expressed by replaced K component dot data, and are therefore simple binary images.

In the normal mode print image PIn, the color of the background BC2s of the second code area CA2n is white, unlike the color of the second background BG2n (dark color and chromatic color). That is, no dots of CMYK are formed on the background BC2n of the second code area CA2n. In the normal mode print image PIn, the color of the background BC1n of the first code area CA1n is the same color as the first background BG1n (bright color and chromatic color). Dots of at least one color of CMY are formed on the background BC1n of the first code area CA1n. Note that since the color of the background BC1n of the first code area CA1n is bright and chromatic, no K dots are formed on the background BC1n of the first code area CA1n.

In the print image PIs in the toner save mode, the color of the background BC2s of the second code area CA2s is white, unlike the color of the second background BG2n (dark color and chromatic color). That is, no dots of CMYK are formed on the background BC2s of the second code area CA2n. In the print image PIs in the toner save mode, the color of the background BC1s of the first code area CA1s is white, unlike the color of the first background BG1s (bright color and chromatic color). That is, no dots of CMYK are formed on the background BC2s of the first code area CA21.

According to the first embodiment described above, the CPU 210 performs color conversion processing on the scan data to generate CMYK image data (S40 in FIG. 2). The CMYK image data includes K component image data corresponding to K toner having the color (black) of code images CI1 and CI2 (FIG. 5). The CPU 210 performs halftone processing on the CMYK image data to generate dot data (S50 in FIG. 2). The dot data includes K component dot data corresponding to K toner (FIG. 5). The CPU 210 generates simple binary data by performing simple binarization processing, which is different from the above-described halftone processing, on partial data indicating the code areas CA1k and CA2k of the K component image data (Fig. 6 S210). The CPU 210 generates print data using the dot data and simple binary data (S210 to S218 in FIG. 6, S60 in FIG. 2). Specifically, the CPU 210 replaces code area data indicating a code area with simple binary data in the K component dot data to generate replaced K component dot data (S210 in FIG. 6), and performs the replacement. Print data including completed K component dot data is generated (S60 in FIG. 2). As a result, in the print images PIn and PIs, the images indicating the code images CI1b and CI2b are simple binary images BA1 and BA2 (FIGS. 9A and 9B), so they are printed using scan data. In this case, the code image within the printed image can be clearly printed.

When printing the code area, it is preferable that the code image be printed clearly from the viewpoint of suppressing poor reading of the code image. In the K component dot image showing the code area, it is ideal from the viewpoint of clarity of the printed image that K dots be formed in the part that constitutes the code image, but not in the background part. In error diffusion processing, errors that occur when binarizing a pixel of interest are diffused to surrounding pixels. Therefore, in the code areas CA1k and CA2k of the K component dot image KDI (FIG. 5) generated by the error diffusion process, K dots may be formed in the background portion. In addition, in the error diffusion process, the generation of dots may be delayed, so in the code areas CA1k and CA2k of the K component dot image KDI generated by the error diffusion process, K dots are not formed in the parts that constitute the code image. There are cases. For this reason, if the K component dot image data generated by error diffusion processing is used as print data as is, there is a possibility that the code image will be printed unclearly. Further, even if the code image on the document is clear, the code image on the scanned image generated using the image sensor may be blurred. Further, the code image on the scanned image may not be uniformly black even if the code image on the document is black. The background of a code image on a scanned image may not be a uniform color even if the background of a code image on a document is a uniform color. For this reason, the error diffusion process attempts to express intermediate gradations in a pseudo manner, so in the code areas CA1k and CA2k of the K component dot image KDI generated by the error diffusion process, the boundary between the code image and the background is unclear. Easy to clarify.

On the other hand, the simple binary images BA1 and BA2 are generated by a simple binarization process in which the value of the pixel of interest is binarized using the threshold THb without depending on the value of a pixel different from the pixel of interest. . For this reason, the problems that occur in the error diffusion processing described above are unlikely to occur in the simple binary images BA1 and BA2. In the simple binary images BA1 and BA2, there is a high possibility that the code images CI1b and CI2b can be expressed such that K dots are formed in the portions that constitute the code image, but no K dots are formed in the background portion. Therefore, the simple binary images BA1 and BA2 can become images that clearly indicate a code image. Therefore, when printing using scan data generated using an image sensor, it is possible to prevent the code images in the print images PIn and PIs from becoming unclear. Thereby, for example, it is possible to suppress the occurrence of reading failures when reading a printed code image.

Furthermore, although images generated by simple binarization cannot express intermediate gradations, it is preferable that images within the code area be expressed in two gradations: a black code image and a monochromatic background. , within the code region of the replaced K component dot image KDIr, there is little need for intermediate gradations to be expressed. In the replaced K component dot image KDIr, since the image in the area different from the code area is an image generated by error diffusion processing, the intermediate gradation is appropriately expressed in the area different from the code area. be able to.

Furthermore, according to the present embodiment, for the code area CA2c in FIG. 8(A) and the code areas CA1c and CA2c in FIG. , to generate replaced C component dot data by replacing it with data indicating that no dots will be formed (S218 in FIG. 6). Similarly, replaced M component dot data and replaced Y component dot data are generated for the M component dot data and the Y component dot data. The CPU 210 generates print data including replaced K component dot data, replaced C component dot data, replaced M component dot data, and replaced Y component dot data (S60 in FIG. 2). In this way, among the component dot data corresponding to the CMY toner, which is different from the K toner that indicates the color of the code image, the partial data indicating the code area is replaced with data indicating that no dots will be formed. The background is not printed using CMY toner. For example, CMY toners are used for the background BC2n of the code area CA2n of the print image PIn in FIG. 9(A) and the backgrounds BC1s and BC2s of the code areas CA1s and CA2s of the print image PIs in FIG. No dots are formed. As a result, the color of these backgrounds BC2n, BC1s, and BC2s becomes the color of the paper (for example, white). Therefore, it is possible to prevent the code image from becoming unclear due to the formation of CMY dots in the background area near the code image.

Furthermore, according to the present embodiment, for the code area CA1c in FIG. 8A, the CPU 210 does not replace partial data indicating the code area in the C component dot data with data indicating that no dots will be formed. . That is, for the code area CA1c in FIG. 8A, the CPU 210 generates print data that includes replaced K component dot data and unreplaced CMY component dot data. As a result, the color of the original document can be reproduced for the color of the background BC1n of the code area CA1n of the print image PIn in FIG. 9(A).

Furthermore, in this embodiment, the CPU 210 determines whether a specific condition is satisfied (S212 to S216 in FIG. 6). If the specific condition is satisfied (YES in any of S212, S214, and S216), the CPU 210 converts partial data indicating the code area of the C component dot data for the code area of interest to indicate that no dots will be formed. The data is replaced to generate replaced C component dot data (S218 in FIG. 6). If the specific condition is not satisfied (NO in all of S212, S214, and S216), the CPU 210 replaces partial data indicating the code area with data indicating that no dots will be formed out of the C component dot data for the code area of interest. Do not replace. The same applies to M component dot data and Y component dot data. That is, if the specific conditions are met, the CPU 210 generates print data including replaced K component dot data and replaced CMY component dot data for the code area of interest, and if the specific conditions are not met, For the code area of interest, print data including replaced K component dot data and unreplaced CMY component dot data is generated. As a result, print data that can appropriately print the image within the code area can be generated depending on whether or not the specific condition is satisfied.

Specifically, the specific conditions include a background color condition indicating that the background color in the code area is a specific color printed using K toner. More specifically, if the saturation Sb of the background color in the code area is less than or equal to the saturation threshold THs, it is determined that the background color condition is satisfied (S114 in FIG. 4, S214 in FIG. 6). When the saturation Sb of the background color is less than or equal to the saturation threshold THs, the background color is achromatic. Achromatic colors are colors that are printed using K toner when printing using general halftone processing such as error diffusion processing. Furthermore, when the brightness Vb of the background color in the code area is equal to or less than the brightness threshold THv, it is determined that the background color condition is satisfied (S120 in FIG. 4, S216 in FIG. 6). When the brightness Vb of the background color is less than or equal to the brightness threshold THv, the background color is dark. The dark color is a color that is printed using K toner when printing using general halftone processing such as error diffusion processing. In this way, based on the saturation Sb and brightness Vb of the background color, it can be appropriately determined whether the background color is a specific color printed using K toner.

In this example, the K component dot image in the code area is replaced with a simple binary image (for example, BA1 and BA2 in FIG. 7(A)), so the background part in the code area has K dots. Not formed. That is, the background within the code area is not printed using K toner. For this reason, if the background color in the code area is dark or achromatic, the color of the document cannot be reproduced with respect to the background color in the code area. For example, even if the background in the code area is printed using only CMY toner, the color of the background in the code area will be lighter than the color of the original, so if only CMY toner is used to print the background, the code will be printed using only CMY toner. There is little point in printing the background within the area. For this reason, in this embodiment, when the background color in the code area is dark or achromatic, CMY dots are not formed in the code area, and the background color in the code area is reproduced. Priority is given to preventing the code image from becoming unclear.

Furthermore, in this embodiment, the determination as to whether or not the background color condition described above is satisfied is determined based on the scan data before the color conversion process (S40 in FIG. 2) is performed (S30 in FIG. 2). , Figure 4). As a result, it is possible to appropriately determine whether or not the above background color condition is satisfied based on the scan data that is RGB image data.

Further, in this embodiment, the CPU 210 determines whether the background color condition is satisfied for each code region of the scan image SI (S106, S126 in FIG. 4). As in the scanned image SI of FIG. 3, the background color may be different for each code area. Even in such a case, each of a plurality of code regions having different background colors can be appropriately printed. Therefore, it is possible to prevent the code images within the plurality of code areas from becoming unclear.

Further, in this embodiment, the printing modes that can be executed using print data include a normal mode and a toner save mode in which the amount of toner consumed is smaller than the normal mode. The specific conditions include a mode condition that the printing mode is toner save mode (S212 in FIG. 6). If the mode condition is satisfied (YES in S212 of FIG. 6), the CPU 210 determines that the specific condition is satisfied. In the toner save mode, it is required to reduce the amount of toner consumed. Consumption of color materials can be reduced by not printing the background of the code area rather than printing the background of the code area using CMY toner. Further, it is preferable not to print the background of the code area from the viewpoint of suppressing the code image from becoming unclear. For this reason, in this embodiment, when the print mode is toner save mode, rather than reproducing the background color in the code area, the purpose is to reduce toner consumption and to make the code image unclear. The priority is to prevent things from happening.

Furthermore, in this embodiment, if the printing mode is the normal mode and the background color of the code area is a chromatic color and a bright color (all of S212, S214, and S216 in FIG. (NO), the background of the code area is printed using CMY toner. In normal mode, it is desired to improve image quality by reproducing the colors of the original rather than reducing toner consumption. Also, if the background color of the code area is a chromatic color and a bright color, only CMY toners are used to reproduce the color of the original for the background color of the code area, without using K toner. can. Furthermore, if the background color of the code area is a chromatic color and a bright color, there is a large color difference between the background and the code image in the code area, so the background of the code area is printed using CMY toner. Even so, the code image is less likely to become unclear. For this reason, in this embodiment, when the printing mode is the normal mode and the background color of the code area is chromatic and bright, CMY toner is used to print the code area. By printing the background, it is possible to prevent the code image from becoming unclear and to prevent the image quality from deteriorating.

Furthermore, in this embodiment, the halftone process executed in S50 of FIG. 2 is an error diffusion process. As a result, compared to, for example, a case where dither processing is employed as halftone processing, it is possible to suppress moire from occurring in the print images PIn and PIs, and to suppress the code image from becoming unclear.

As can be seen from the above description, the scan data of this embodiment is an example of target image data, and the CMYK image data is an example of converted image data. The K toner in this embodiment is an example of the first color material, and the CMY toners are examples of the second color material. The K component image data of this embodiment is an example of first component image data. The K component dot data of this embodiment is an example of first component dot data, and the CMY component dot data is an example of second component dot data.

B. Second Embodiment FIG. 10 is a flowchart of image processing in a second embodiment. In the image processing of the first embodiment, as shown in FIG. 2, the background color analysis process (S30 in FIG. 2) is executed before the color conversion process in S40. In contrast, in the second embodiment, as shown in FIG. 10, the background color analysis process (S42B in FIG. 10) is executed after the color conversion process in S40.

FIG. 11 is a flowchart of background color analysis processing in the second embodiment. In the first embodiment, the background color analysis process is performed using scan data (RGB image data). In contrast, the background color analysis process of the second embodiment is executed using CMYK image data after color conversion processing.

In S104B, the CPU 210 determines whether a code area has been specified in the scan image SI in the code area specifying process of S25 in FIG. If the code region is not specified (S104B: NO), the CPU 210 ends the background color analysis process. If a code region is identified (S104B: YES), in S106B, CPU 210 selects one code region of interest from among the one or more identified code regions.

In S108B, the CPU 210 classifies the plurality of pixels in the code area of interest into code constituent pixels and background pixels. Specifically, the CPU 210 classifies pixels having color values within a predetermined black pixel range as code constituent pixels, and classifies pixels having color values outside the black pixel range as background pixels. Execute value processing. The black pixel range is a range of CMYK values indicating black, and when each CMYK component value takes a value from 0 to 255, (C, M, Y, K) = (0, 0, 0, 255). The range of CMYK values includes. The black pixel range is, for example, a range that satisfies 0≦C≦10, 0≦M≦10, 0≦Y≦10, and 240≦K≦255.

In S110B, the CPU 210 identifies the background color of the code area of interest using the color values (CMYK values) of a plurality of background pixels within the code area of interest. In this embodiment, the average value of the color values of a plurality of background pixels is calculated as the color value indicating the background color. Note that as the color value indicating the background color, a statistical value different from the average value of the color values of background pixels, such as a median value or a mode value, may be used. For example, as the K component value of the background color, the average value of the K component values of each pixel of the background pixels is calculated using the K component image data.

In S114B, the CPU 210 determines whether the K component value of the background color of the code area of interest is greater than or equal to a predetermined threshold THk. The threshold value THk is, for example, 20 when the K component value takes a value from 0 to 255. If the K component value of the background color is greater than or equal to the threshold THk (S114B: YES), in S116B, the CPU 210 determines that the background color of the code area of interest is the color using K toner. If the K component value of the background color is less than the threshold THk (S114: NO), in S118B, the CPU 210 determines that the background color of the code area of interest is a K toner-free color. The K toner used color is a color that is printed using K toner when printing is performed using general halftone processing such as error diffusion processing. The K toner-free color is a color that is printed without using K toner when printing is performed using general halftone processing such as error diffusion processing. For example, the achromatic colors and dark colors in the first embodiment are colors using K toner. The bright and chromatic colors of the first embodiment are colors in which K toner is not used. For this reason, in the example of FIG. 3, the background color of the first code area CA1 (FIG. 3) is determined to be a K toner-free color, and the background color of the second code area CA2 (FIG. 3) is determined to be a K toner-free color. It is determined that the color uses toner.

In S126B, CPU 210 determines whether all code areas have been processed. If there is an unprocessed code area (S126B: YES), the CPU 210 returns the process to S106B. If all code regions have been processed (S126B: NO), the CPU 210 ends the background color analysis process.

When the background color analysis processing is completed, in S45 and S50 of FIG. 10, recording gamma correction processing and halftone processing are executed, similar to S45 and S50 of FIG. 2, to generate dot data.

In S55B of FIG. 10, the CPU 210 executes code binarization processing. The code binarization process of the second embodiment differs from the code binarization process of the first embodiment (FIG. 11) in some parts. FIG. 12 is a flowchart of code binarization processing in the second embodiment. In the code binarization process of FIG. 12, S214B of FIG. 12 is executed instead of S214 and S216 of FIG.

In S214B, the CPU 210 determines whether the background color of the code area of interest is a color using K toner or a color not using K toner, based on the result of the background color analysis process (FIG. 11). As described above, the background color of the first code area CA1 (FIG. 3) is determined to be a color that does not use K toner, so if the code area of interest is the first code area CA1, this step The background color is determined to be a color in which K toner is not used. As described above, the background color of the second code area CA2 is determined to be the K toner color in the background color analysis process. For this reason, when the code area of interest is the second code area CA2 (FIG. 3), it is determined in this step that the background color is the K toner color.

If the background color of the code area of interest is the K toner color (S214B: YES), the CPU 210 advances the process to S218. If the color does not use K toner in the code area of interest (S214B: NO), the CPU 210 advances the process to S220. The other processes of the code binarization process in FIG. 12 are the same as the processes with the same symbols in FIG. 11, so the description thereof will be omitted.

The code binarization process of the second embodiment also produces replaced K component image data, replaced C component dot data, and replaced M component dot data similar to the code binarization process of the first embodiment. Replaced Y component dot data is generated (FIG. 7(B), FIG. 8).

When the code binarization process is completed, in S60 of FIG. 10, the CPU 210 generates print data including dot data that has undergone the code binarization process, similarly to S60 of FIG. In S65 of FIG. 10, the CPU 210 outputs the generated print data to the print execution unit 280, similar to S65 of FIG. When the print execution unit 280 receives the print data, it uses the print data to print a print image indicated by the dot data on paper. As a result, in the second embodiment as well, the print images PIn and PIs shown in FIG. 9 are printed as in the first embodiment.

According to the second embodiment described above, the CPU 210 uses the K component image data to calculate the component value (K component value) corresponding to the K toner of the background color of the code area (S110B in FIG. 11), If the K component value of the background color is greater than or equal to the threshold THk (YES in S114B of FIG. 11, YES in S214B of FIG. 12), the portion of the CMY component dot data indicating the code region for the code region of interest is The data is replaced with data indicating that no dots will be formed (S128 in FIG. 12). That is, the CPU 210 determines that the background color condition is satisfied when the K component value of the background color is greater than or equal to the threshold THk. As a result, using the K component value of the CMYK image data, it is possible to appropriately determine whether the background color is a specific color printed using K toner. Therefore, images within the code area (background and code image) can be appropriately printed.

C. Third Embodiment In the first and second embodiments, printing using CMYK toners, that is, color printing (color copy), was described, but in the third embodiment, printing using only K toner, That is, a case where monochrome printing (monochrome copy) is performed will be described. FIG. 13 is a flowchart of image processing in the third embodiment. The processing from S10 to S25 in FIG. 13 is the same as the processing from S10 to S25 in FIG.

In S40C of FIG. 13, the CPU 210 performs monochrome conversion processing on the scan data (RGB image data) to generate K component image data. The monochrome conversion process is a process of converting the RGB values of each pixel of scan data into density values. Image data having the density value as the value of each pixel is generated as K component value image data. The monochrome conversion process may be performed using a known conversion formula, or may be performed with reference to a table showing the correspondence between RGB values and density values.

In S45 and S50 of FIG. 13, similar to S45 and S50 of FIG. 2, recording gamma correction processing and halftone processing are executed to generate dot data. However, in the third embodiment, converted image data containing only K component image data is generated in S40C, and CMY component image data is not generated, so recording gamma correction processing and halftone processing are performed on the K component image data. Executed only on data. For this reason, the generated dot data includes only K component dot data, and CMY component dot data is not generated.

In S55C of FIG. 13, the CPU 210 executes code binarization processing. The code binarization process of the third embodiment is different from the code binarization process of the first and second embodiments (FIGS. 6 and 12), and is executed using only the K component dot data. FIG. 14 is a flowchart of code binarization processing according to the third embodiment. The code binarization process in FIG. 14 is a process that includes only the process for the K component dot data and does not include the process for the CMY component dot data in the code binarization process in FIG. Specifically, the code binarization process in FIG. 14 is the code binarization process in FIG. 6 except that S212, S214, S216, and S218 are removed. By the code binarization process of the third embodiment, replaced K component dot data representing the replaced K component dot image KDIr shown in FIG. 7(B) is generated.

When the code binarization process ends, in S60C of FIG. 13, the CPU 210 generates print data including the replaced K component dot data. In S65 of FIG. 13, the CPU 210 outputs the generated print data to the print execution unit 280, similar to S65 of FIG. Upon receiving the print data, the print execution unit 280 uses the print data to print a print image indicated by the print data on paper. As a result, in the third embodiment, the replaced K component dot image KDIr shown in FIG. 7(B) is printed on paper as a print image.

According to the third embodiment described above, when generating print data for monochrome printing, the CPU 210 uses scan data to generate converted image data containing only K component image data (see FIG. (S40C), generates dot data including only K component dot data (S50 in FIG. 13), and generates print data including replaced K component dot data (S60 in FIG. 13). As a result, it is possible to prevent the code image from becoming unclear even in monochrome printing.

D. Modification (1) In the first embodiment, scan data (RGB image data) is used to determine whether the background color condition is satisfied, and in the second embodiment, CMYK image data is used to determine the background color condition. It is determined whether the color condition is satisfied. Instead, the K component dot data may be used to determine whether the background color condition is satisfied. For example, the CPU 210 uses the K component dot data to determine whether there are a predetermined number of K dots in the background region (for example, quiet zone QZ) of the code region of the K component dot image KDI, and If there are dots, it may be determined that the background color condition is satisfied.

(2) In the first embodiment, the saturation Sb and brightness Vb of the background color are used to determine whether the background color condition is satisfied. Alternatively, for example, it may be determined whether the background color condition is satisfied using only one of the saturation Sb and the brightness Vb of the background color.

Furthermore, in the first embodiment, it may be determined whether the background color condition is satisfied without using the saturation Sb and brightness Vb of the background color. For example, data indicating the range of RGB values indicating colors printed using K toner may be stored in the nonvolatile storage device 230 in advance. In this case, the CPU 210 may determine that the background color condition is satisfied when the RGB values indicating the background color of the code region are within the range of the RGB values.

(3) The determination of the background color conditions in the first and second embodiments (S214 and S216 in FIGS. 4 and 6, and S214B in FIGS. 11 and 12) may be omitted. For example, in the normal mode, the CPU 210 does not always replace the partial data indicating the code area of the CMY component dot data with data indicating that no dots will be formed, and in the toner save mode, the CPU 210 always replaces the CMY component dot data. Of the dot data, partial data indicating the code area may be replaced with data indicating that no dots will be formed.

(4) The determination of the print mode in the first and second embodiments (S212 in FIG. 6, S212 in FIGS. 11 and 12) may be omitted. For example, regardless of the print mode, if the background color condition is not satisfied, the CPU 210 does not replace partial data indicating a code area of the CMY component dot data with data indicating that no dots will be formed. , when the background color condition is satisfied, partial data indicating the code area among the CMY component dot data may be replaced with data indicating that no dots will be formed.

(5) Both the print mode determination and background color condition determination in the first and second embodiments may be omitted. In this case, the CPU 210 may always replace the partial data indicating the code area of the CMY component dot data with data indicating that no dots will be formed, or may always replace the CMY component dot data with data indicating that no dots will be formed. It may be included in the print data as is. In addition, instead of determining the print mode and background color conditions, it is also possible to switch whether to replace partial data indicating a code area with data indicating that no dots will be formed, based on user instructions. good.

(6) In the first and second embodiments described above, the background color condition is determined for each code area. Alternatively, for example, the background color condition may be determined for each scan data. For example, the background color condition may be determined by specifying the ground color of the document based on the RGB values of a plurality of pixels in the outer edge portion of the scanned image SI, and using the ground color as the background color of the code area.

(7) In each of the above embodiments, error diffusion processing is employed as the halftone processing, but dither processing using a dither matrix may also be employed. Even in the case of dither processing, there is a higher possibility that K dots will be formed in the background of the code area compared to simple binarization processing. For this reason, even in the case of dither processing, by replacing the partial data indicating the code area in the K component dot data with simple binary data, it is possible to suppress the code image from becoming unclear in the printed image. can do.

(8) In each of the above embodiments, the print execution unit 280 is an electrophotographic print execution unit. Alternatively, the print execution unit 280 may be an inkjet type print execution unit that ejects ink as a coloring material to form an image on paper.

(9) In each of the above embodiments, the image processing in FIG. 2 is executed by the CPU 210 of the multifunction device 200. Alternatively, the image processing in FIG. 2 may be executed by the CPU of the terminal device 100 that is communicably connected to the multifunction device 200. In this case, the terminal device 100 acquires scan data by receiving the scan data from the multifunction peripheral 200 in S10 of FIG. Alternatively, scan data or captured image data stored in the storage device of the terminal device 100 may be acquired as the target image data. Further, in S65 of FIG. 2, the terminal device transmits the generated print data to the multifunction device 200. Further, the image processing in FIG. 2 may be executed by a server (for example, a cloud server) that can communicate with the multifunction peripheral 200 and the terminal device 100. In this case, for example, in S10 of FIG. 2, the server acquires target image data (scan data or captured image data) from the multifunction device 200 or the terminal device 100. In S65 of FIG. 2, the server transmits the generated print data to the multifunction device 200. Thus, in each of the above embodiments, the multifunction device 200 is an example of an image processing device, and in this modification, the terminal device 100 and the server are examples of an image processing device.

(10) In each of the above embodiments, part of the configuration realized by hardware may be replaced with software, or conversely, part or all of the configuration realized by software may be replaced by hardware. You can do it like this. For example, some of the image processing in FIG. 2 (for example, color conversion processing and halftone processing) may be performed by dedicated hardware such as an ASIC.

Although the present invention has been described above based on examples and modifications, the embodiments of the invention described above are for facilitating understanding of the present invention, and are not intended to limit the present invention. The present invention may be modified and improved without departing from the spirit and scope of the claims, and the present invention includes equivalents thereof.

100...Terminal device, 200...Multifunction device, 210...CPU, 220...Volatile storage device, 230...Nonvolatile storage device, 240...Display section, 250...Operation section, 270...Communication ID, 280...Print execution section, 290 ...Reading execution unit, BA1, BA2...Simple binary image, CDI...C component dot image, CDIr...Replaced C component dot image, CDIs...Replaced C component dot image, CI...C component image, KDI...K component dot Image, KDIr...Replaced K component dot image, KI...K component image, PG...Computer program, PIn, PIs...Printed image, SI...Scanned image

Claims (14)

An image processing device,
an image acquisition unit that acquires target image data indicating a target image including a code image and generated using an image sensor;
A color conversion unit that performs color conversion processing on the target image data to generate converted image data, wherein the converted image data includes one or more color materials corresponding to one or more color materials used for printing. the color converting unit including component image data, the one or more component image data including first component image data corresponding to a first color material having a color of the code image;
A halftone processing unit that performs halftone processing on the converted image data to generate dot data indicating a dot formation state, the dot data including one or more color materials corresponding to the one or more color materials. the halftone processing unit, wherein the one or more component dot data includes first component dot data corresponding to the first color material;
A binarization process of generating code binary data by performing a specific binarization process different from the halftone process on partial data indicating a code area including the code image among the first component image data. The specific binarization process is a process of binarizing the value of the pixel of interest using a specific threshold value without depending on the value of a pixel different from the pixel of interest. a processing section;
a generation unit that generates print data using the dot data and the code binary data;
Equipped with
The generation unit is
replacing partial data indicating the code region in the first component dot data with the code binary data to generate replaced first component dot data;
An image processing device that generates the print data including the replaced first component dot data. The image processing device according to claim 1,
The one or more component dot data includes the first component dot data and one or more second component dot data corresponding to one or more second colorants different from the first colorant. component dot data,
The generation unit is
replacing partial data indicating the code region among the one or more second component dot data with data indicating that the dot is not formed to generate one or more replaced second component dot data;
An image processing apparatus that generates the print data including the replaced first component dot data and the one or more replaced second component dot data. The image processing device according to claim 1, further comprising:
The one or more component dot data includes the first component dot data and one or more second component dot data corresponding to one or more second colorants different from the first colorant. component dot data,
The generation unit is an image processing device that generates the print data including the replaced first component dot data and the one or more second component dot data. The image processing device according to claim 2, further comprising:
It includes a condition determination unit that determines whether a specific condition is satisfied,
The generation unit is
When the specific condition is satisfied, generating the print data including the replaced first component dot data and the one or more replaced second component dot data;
An image processing apparatus that generates the print data including the replaced first component dot data and the one or more second component dot data when the specific condition is not satisfied. The image processing device according to claim 4,
The specific condition includes a background color condition indicating that the background color in the code area is a specific color printed using the first color material,
The condition determination unit is an image processing device that determines that the specific condition is satisfied when the background color condition is satisfied. The image processing device according to claim 5,
The first coloring material is a black coloring material,
The condition determining unit determines that the background color condition is satisfied when the saturation of the background color is less than or equal to a reference value. The image processing device according to claim 5 or 6,
The first coloring material is a black coloring material,
The condition determining unit determines that the background color condition is satisfied when the brightness of the background color is less than or equal to a reference value. The image processing device according to claim 6 or 7,
The condition determination unit is an image processing device that determines whether the background color condition is satisfied based on the target image data before the color conversion process is performed. The image processing device according to claim 5,
The condition determining unit is
calculating a component value corresponding to the first color material of the background color using the first component image data;
An image processing device that determines that the background color condition is satisfied when a component value corresponding to the first color material of the background color is greater than or equal to a reference value. The image processing device according to any one of claims 5 to 9,
The target image includes a plurality of code regions each including the code image,
The condition determining unit is an image processing device that determines whether the background color condition is satisfied for each code region. The image processing device according to claim 4,
Print modes that can be executed using the print data include a first print mode and a second print mode that consumes less color material than the first print mode,
The specific condition includes a mode condition that the print mode is a second print mode,
The condition determination unit is an image processing device that determines that the specific condition is satisfied when the mode condition is satisfied. The image processing device according to any one of claims 1 to 11,
The image processing device, wherein the halftone processing is error diffusion processing. The image processing device according to claim 1,
When generating the print data for monochrome printing,
The color conversion unit uses the target image data to generate the converted image data including only the first component image data,
The halftone processing unit generates the dot data including only the first component dot data,
The generation unit is an image processing device that generates the print data including the replaced first component dot data. A computer program,
an image acquisition function that acquires target image data that is generated using an image sensor and is target image data indicating a target image including a code image;
A color conversion function that executes color conversion processing on the target image data to generate converted image data, wherein the converted image data includes one or more color materials corresponding to one or more color materials used for printing. a color conversion function including component image data, the one or more component image data including first component image data corresponding to a first color material having a color of the code image;
A halftone processing function that performs halftone processing on the converted image data to generate dot data indicating a dot formation state, wherein the dot data includes one or more color materials corresponding to the one or more color materials. the halftone processing function, the one or more component dot data including first component dot data corresponding to the first color material;
A binarization process of generating code binary data by performing a specific binarization process different from the halftone process on partial data indicating a code area including the code image among the first component image data. The specific binarization process is a process of binarizing the value of the pixel of interest using a specific threshold value without depending on the value of a pixel different from the pixel of interest. processing function and
a generation function that generates print data using the dot data and the code binary data;
to be realized by a computer,
The generation function is
replacing partial data indicating the code region in the first component dot data with the code binary data to generate replaced first component dot data;
A computer program that generates the print data including the replaced first component dot data.

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