JP7331595B2 - Color conversion parameter generation device, color conversion parameter generation method and program - Google Patents

Description

The present invention relates to a color conversion parameter generation device, a color conversion parameter generation method, and a program.

A general printing apparatus performs printing using process colors of cyan (C), magenta (M), yellow (Y), and black (K). The colors of the scanned image data (RGB values) and the original image data (CMYK values) obtained by reading the color sample in order to aim for the color reproduction of the color sample (target output) printed based on the original image data. A system that performs color matching by correcting a color conversion table used for color conversion of document image data based on the correspondence relationship is used (see Patent Document 1).

JP-A-2016-48900

However, if a printing company, etc., has reproduction settings for overlapping objects such as overprints and transparent objects in the color sample/document image data brought in when receiving an order from a client, this reproduction setting will not be applied when printing the color sample. There was a problem of not knowing whether it was valid or invalid. If the reproduction setting is enabled and if the reproduction setting is disabled, the print result will be different. Therefore, the system will associate wrong colors between the scanned image data of the color sample and the original image data, and color conversion will occur. It is possible to modify the table to the wrong color.

SUMMARY OF THE INVENTION An object of the present invention is to prevent unintended color conversion when there is an overlapping object in document image data.

In order to solve the above problems, the invention described in claim 1 acquires read image data of a color sample, acquires document image data corresponding to the color sample, and stores the read image data and the document image data. A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the document image data based on If the document image data includes the reproduction setting, it is notified that the document image data includes the reproduction setting, and if the document image data includes the reproduction setting, the read image data and the document A difference from the image data is acquired, and if the difference is equal to or greater than a predetermined value, an image based on the document image data is displayed on the display unit, and the display mode of the area corresponding to the reproduction setting in the image is changed. , a display mode different from that of other regions.

According to the second aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the original image data, wherein the control unit determines whether or not the original image data includes a reproduction setting for an overlapping object; When the document image data includes the reproduction setting, the fact that the document image data includes the reproduction setting is notified, and when the color conversion parameter is generated, the area corresponding to the reproduction setting of the read image data and the document image data is displayed. A selection means is provided for selecting whether or not to use the information, and the control section generates the color conversion parameters based on the selection result of the selection means.

The invention according to claim 3 is the color conversion parameter generation device according to claim 2 , wherein the control unit displays an image based on the document image data when the document image data includes the reproduction setting. section, and the display mode of the area corresponding to the reproduction setting in the image is set to be a display mode different from that of the other areas.

According to the fourth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the original image data, wherein the control unit determines whether or not the original image data includes a reproduction setting for an overlapping object; When the document image data includes the reproduction settings, it is notified that the reproduction settings are included, and when the document image data includes the reproduction settings, at least two of the document image data having changed the reproduction settings. An image is generated, the at least two images are displayed on the display unit, and the display mode of the area corresponding to the reproduction setting in the at least two images is set to be a different display mode from the other areas.

According to the fifth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the original image data, wherein the control unit determines whether or not the original image data includes a reproduction setting for an overlapping object; When the document image data includes the reproduction settings, it is notified that the reproduction settings are included, and when the document image data includes the reproduction settings, at least two of the document image data having changed the reproduction settings. generating an image, obtaining a difference from the read image data for each of the at least two images, and obtaining the color conversion parameter based on the image corresponding to the reproduction setting with the smallest difference and the read image data; to generate

The invention according to claim 6 is the color conversion parameter generation device according to claim 4 or 5 , wherein the control unit generates the at least two images by limiting the range of the area corresponding to the reproduction setting. do.

In a seventh aspect of the invention, in the color conversion parameter generating device according to the sixth aspect, the control unit controls the area including the feature points used for alignment between the read image data and the document image data. By definition, said at least two images are generated.

According to the eighth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. a color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating color conversion parameters related to color conversion of a a step of notifying that the document image data includes the reproduction setting by the control unit when the document image data includes the reproduction setting; a step of notifying that the document image data includes the reproduction setting; acquiring a difference between the read image data and the document image data by the control unit; and displaying an image based on the document image data on a display unit when the difference is equal to or greater than a predetermined value by the control unit. and setting the display mode of the area corresponding to the reproduction setting in the image to be different from the display mode of other areas.

According to the ninth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. a color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating color conversion parameters related to color conversion of a a step of notifying that the original image data includes the reproduction setting by the control unit when the original image data includes the reproduction setting ; and a step of generating the color conversion parameter by the control unit. a step of judging a selection result of a selection means as to whether or not to use information of an area corresponding to the reproduction setting of the read image data and the document image data; and generating the color transformation parameters based on .
According to a tenth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. a color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating color conversion parameters related to color conversion of a a step of notifying that the document image data includes the reproduction setting by the control unit when the document image data includes the reproduction setting; a step of notifying that the document image data includes the reproduction setting; a step of generating at least two images with the reproduction settings changed for the document image data by the control unit; and setting a display mode of the area corresponding to the reproduction setting in the display mode to a display mode different from other areas.
According to the eleventh aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. a color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating color conversion parameters related to color conversion of a a step of notifying that the document image data includes the reproduction setting by the control unit when the document image data includes the reproduction setting; a step of notifying that the document image data includes the reproduction setting; generating at least two images in which the reproduction settings have been changed for the document image data by the control unit; and obtaining a difference between each of the at least two images and the read image data by the control unit. and generating the color conversion parameters based on the image corresponding to the reproduction setting with the smallest difference and the read image data.

According to a twelfth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. determining whether or not the original image data includes reproduction settings for overlapping objects in a computer of a color conversion parameter generation device that generates color conversion parameters for color conversion of the original image data; a step of notifying that the reproduction setting is included when the document image data includes the reproduction setting; obtaining a difference between the read image data and the document image data when the document image data includes the reproduction setting; is equal to or greater than a predetermined value, an image based on the document image data is displayed on the display unit, and the display mode of the area corresponding to the reproduction setting in the image is set to a different display mode from the other areas. It is a program for executing a process .
According to the thirteenth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. determining whether or not the original image data includes reproduction settings for overlapping objects in a computer of a color conversion parameter generation device that generates color conversion parameters for color conversion of the original image data; a step of notifying that the reproduction setting is included, and whether information of the area corresponding to the reproduction setting of the read image data and the document image data is used when generating the color conversion parameter, if A program for executing a step of judging a selection result of a selection means as to whether or not, and a step of generating the color conversion parameter based on the selection result of the selection means.
In the fourteenth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. determining whether or not the original image data includes reproduction settings for overlapping objects in a computer of a color conversion parameter generation device that generates color conversion parameters for color conversion of the original image data; and generating at least two images with changed reproduction settings for the document image data when the document image data includes the reproduction settings. and causing the display unit to display the at least two images, and setting the display mode of the area corresponding to the reproduction setting in the at least two images to a display mode different from that of other areas. It is a program for
According to the fifteenth aspect of the invention, read image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and the document image data is obtained based on the read image data and the document image data. determining whether or not the original image data includes reproduction settings for overlapping objects in a computer of a color conversion parameter generation device that generates color conversion parameters for color conversion of the original image data; and generating at least two images with changed reproduction settings for the document image data when the document image data includes the reproduction settings. obtaining a difference between each of the at least two images and the read image data; and determining the color conversion parameter based on the image corresponding to the reproduction setting with the smallest difference and the read image data. and a program for executing a step of generating.

According to the present invention, unintended color conversion can be prevented when there is an overlapping object in document image data.

1 is a diagram showing a system configuration of an image forming system according to a first embodiment of the invention; FIG. It is a block diagram which shows the functional structure of PC. FIG. 10 is a diagram showing the flow of correction of a color conversion table (target profile); 4 is a flowchart showing first color conversion parameter generation processing; (a) is an example of document image data. (b) is an example of a preview screen. FIG. 10 is a flowchart showing second color conversion parameter generation processing according to the second embodiment; FIG. FIG. 14 is a flowchart showing third color conversion parameter generation processing in the third embodiment; FIG. FIG. 10 is an example of a preview screen containing two images with modified reproduction settings; FIG. FIG. 11 is a diagram for explaining the range of a region to be processed in Modification 1 of the third embodiment; FIG. FIG. 11 is a diagram for explaining feature points used for alignment in Modification 2 of the third embodiment; FIG. FIG. 14 is a flowchart showing fourth color conversion parameter generation processing according to the fourth embodiment; FIG.

An embodiment of a color conversion parameter generation device according to the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[First embodiment]
FIG. 1 shows the system configuration of an image forming system 100 according to the first embodiment. As shown in FIG. 1, an image forming system 100 is configured with a PC (Personal Computer) 10 as a color conversion parameter generation device, a scanner 20 and a printer 30 . Each device is connected for data communication via a communication network N such as a LAN (Local Area Network).

The PC 10 corrects the target profile used when matching the color of the output material of the printer 30 with the color of the color sample, and provides the printer 30 with the target profile. The PC 10 transmits a print instruction including image data to be printed to the printer 30 .

The scanner 20 reads the color sample and generates read image data (RGB values). A scanner installed in the printer 30 may be used as the scanner 20 .

The printer 30 uses four process colors, cyan (C), magenta (M), yellow (Y), and black (K), and uses color materials such as CMYK toners and inks to print images on paper. It is an image forming apparatus that forms an image. The printer 30 is composed of a controller and a printer engine.
Based on the print instruction sent from the PC 10, the controller performs arithmetic processing such as color conversion processing, rasterization processing, and screening processing on the image data to be printed to generate raster data (CMYK values).
The printer engine performs print processing based on raster data (CMYK values) generated by the controller.

FIG. 2 shows the functional configuration of the PC 10. As shown in FIG. As shown in FIG. 2, the PC 10 includes a control section 11, a display section 12, an operation section 13, a communication section 14, a storage section 15, and the like.

The control unit 11 includes a CPU (Central Processing Unit) 111 , a ROM (Read Only Memory) 112 , a RAM (Random Access Memory) 113 and the like, and controls each unit in the PC 10 . The CPU 111 reads various programs stored in the ROM 112 or the storage unit 15, expands them in the RAM 113, and executes various processes according to the expanded programs. The ROM 112 is a read-only memory that stores various programs and various data. RAM 113 temporarily stores programs and data as a work area.

The display unit 12 includes an LCD (Liquid Crystal Display) monitor, and displays various screens in accordance with display signal instructions input from the control unit 11 .

The operation unit 13 includes a keyboard having cursor keys, character input keys, various function keys, etc., and a pointing device such as a mouse. output to Further, the operation unit 13 may be configured by a touch panel laminated on the display unit 12 and may output an operation signal to the control unit 11 according to the position of the touch operation by the operator's finger or the like.

The communication unit 14 is configured by a network interface or the like, and transmits and receives data to and from an external device connected via the communication network N.

The storage unit 15 is a storage device that stores various programs and various data.
The storage unit 15 stores color conversion profiles. A color conversion profile is a profile used for color conversion, and includes a scanner profile, a printer profile, a target profile, and the like.
The scanner profile represents a correspondence relationship (reading characteristics of the scanner 20) between read values (RGB values) of the scanner 20 and color values (L ^* a ^* b ^* values), and is obtained in advance.
The printer profile represents the correspondence (output characteristics of the printer 30) between image data (CMYK values) and color values (L ^* a ^* b ^* values) used in printing by the printer 30, and is obtained in advance. there is
The target profile represents the correspondence relationship between the original image data (CMYK values) input to the target printing machine that printed the color sample and the color values (L ^* a ^* b ^* values) obtained from the color sample. be. A target profile is updated as it is modified.

The control unit 11 acquires read image data (RGB values) obtained by reading the color sample from the scanner 20 .

The control unit 11 acquires document image data (CMYK values) corresponding to the color sample. The document image data is the image data on which the color sample is printed. For example, a PDF file or the like is used as the document image data.

Based on the read image data and the document image data, the control unit 11 generates color conversion parameters for color conversion of the document image data. Specifically, the control unit 11 generates color conversion parameters for the target profile.

The control unit 11 determines whether or not the document image data includes reproduction settings for overlapping objects. Reproduction settings for overlapping objects (hereinafter referred to as "overlapping reproduction settings" or simply "reproduction settings") are settings that determine how to reproduce the colors of overlapping objects. be. Overprint reproduction settings include settings such as overprinting and transparent objects.

Overprint is a setting for superimposing a foreground object on a background object. printed. When overprinting is disabled (OFF), only the color of the object in the foreground is printed without the color of the object in the background in the portion where the objects overlap.

The transparent object is a setting that makes the front object translucent based on transparency, transparency, etc., when the objects are superimposed.

When the document image data includes the reproduction setting, the control unit 11 notifies that the reproduction setting is included.
Specifically, when the document image data includes the reproduction setting, the control unit 11 causes the display unit 12 to display an image based on the document image data, and changes the display mode of the area corresponding to the reproduction setting in the image. , a display mode different from that of other regions.

The operation unit 13 is used to select whether or not to use the information of the area corresponding to the reproduction setting of the read image data and the document image data when generating the color conversion parameters. That is, the operation unit 13 functions as selection means.

The control unit 11 generates color conversion parameters based on the selection result of the operation unit 13 (selection means). Specifically, when it is selected to use the information of the area corresponding to the reproduction setting, the control unit 11 selects the information of the entire area of the read image data and the document image data (the information of the area corresponding to the reproduction setting). information.) to generate color conversion parameters. On the other hand, when it is selected not to use the information of the area corresponding to the reproduction setting, the control unit 11 uses the information of the area excluding the area corresponding to the reproduction setting of the read image data and the document image data. , to generate the color transformation parameters.

Next, referring to FIG. 3, the flow of correction of the color conversion table (target profile) will be described.
(1) Extract the CMYK values of each pixel from the document image data.
(2) Extract the RGB values of each pixel from the read image data obtained by reading the color sample with the scanner 20 .
(3) Since the target profile to be corrected is a CMYK-L ^* a ^* b ^* lookup table (LUT), the RGB values extracted from the read image data are converted to the scanner profile (RGB-L ^* a ^* b ^* LUT ) to L ^* a ^* b ^* values.

(4) Create a table (CMYK-L ^* a ^* b ^* table) in which CMYK values and L*a ^* b ^* values are associated with ^each other at corresponding positions of the document image data and the read image data. Specifically, feature points such as edges (contours) and corners are extracted from each of the document image data and the read image data, and the document image data and the read image data are aligned based on the feature points. Then, the combinations of the CMYK values of the document image data and the L ^* a ^* b ^* values obtained from the read image data are stored in the CMYK-L ^* a ^* b ^* table for each mutually corresponding position.
(5) Based on the CMYK-L ^* a ^* b ^* table, the correction is reflected in the CMYK target profile (CMYK-L ^* a ^* b ^* ).

Next, the operation of the PC 10 will be explained.
FIG. 4 is a flow chart showing the first color conversion parameter generation process executed by the PC 10. As shown in FIG. This processing is implemented by software processing in cooperation with the CPU 111 of the control unit 11 and the programs stored in the storage unit 15 .

First, the scanner 20 reads a color sample and generates read image data (RGB values).
The control unit 11 acquires read image data (RGB values) obtained by reading a color sample from the scanner 20 via the communication unit 14 (step S1). The control unit 11 causes the storage unit 15 to store the acquired read image data.

Next, the control unit 11 acquires document image data (CMYK values) corresponding to the color sample from an external device via the communication unit 14 (step S2). The control unit 11 causes the storage unit 15 to store the acquired document image data.

Next, the control section 11 analyzes the document image data (step S3), and determines whether or not the document image data includes a superposition reproduction setting (step S4).

If the document image data includes the superposition reproduction setting (step S4; YES), the control section 11 causes the display section 12 to display an image based on the document image data, and displays the area corresponding to the reproduction setting in the image. is set to a display mode different from that of other areas (step S5). The control unit 11 notifies that there is a superposition reproduction setting by highlighting the area corresponding to the reproduction setting on the image displayed on the display unit 12 .

For example, FIG. 5B shows an example of the preview screen 121 displayed on the display unit 12 when the document image data 40 includes the overprint area 41 as shown in FIG. 5A. The preview screen 121 includes an image display area 50, a check box C1, and an adjustment button B1.
An image (preview image) based on the document image data 40 is displayed in the image display area 50 . In the image display area 50, an overprint area (area corresponding to reproduction setting) 51 in the image is displayed so as to be distinguishable from other areas. For example, the control unit 11 blinks the overprint area (object) 51 or displays it in a different color from the surroundings. Since the purpose here is to notify the presence of the overprint area 51, the color of the overprint area 51 may be different from the actual color (the color in the document image data 40). Alternatively, the overprint area 51 may be emphasized and displayed by superimposing a dashed line or a thick line on the boundary of the overprint area 51 .
The check box C1 is checked when excluding the area corresponding to the reproduction setting from the information (original image data, read image data) used to generate the color conversion parameters.
The adjustment button B1 is pressed when instructing generation of color conversion parameters.

Next, the user operates the operation unit 13 to select whether or not to use the information of the area corresponding to the reproduction setting of the read image data and the document image data when generating the color conversion parameters.
For example, in the preview screen 121 of FIG. 5B, if the user does not check the check box C1 and presses the adjustment button B1, the control unit 11 sets the reproduction setting when generating the color conversion parameters. The information in the corresponding area will be used. On the other hand, in the preview screen 121, when the user checks the check box C1 and presses the adjustment button B1, the control unit 11 generates the information of the area corresponding to the reproduction setting when generating the color conversion parameters. will be excluded.
Based on the selection operation from the operation unit 13, the control unit 11 determines whether or not to use the information of the area corresponding to the reproduction setting when generating the color conversion parameters (step S6).

When using the information of the area corresponding to the reproduction setting (step S6; YES), the control unit 11 uses the information of the area corresponding to the reproduction setting of the read image data and the document image data, that is, the reading Color conversion parameters are generated based on the entire area of the image data and the document image data (step S7). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .

In step S6, if the information on the area corresponding to the reproduction setting is not used (step S6; NO), the control unit 11 excludes the information on the area corresponding to the reproduction setting from the read image data and the document image data. , color conversion parameters are generated based on information other than the area corresponding to the reproduction setting (step S8). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .

In step S4, if the document image data does not include the overlay reproduction setting (step S4; NO), the control section 11 generates color conversion parameters based on the read image data and the document image data (step S9). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .
After step S7, step S8, or step S9, the first color conversion parameter generation process ends.

The modified target profile is sent from PC 10 to printer 30 . When the document image data is printed by the printer 30, the controller performs color conversion from the document image data (CMYK values) to color values (L ^* a ^* b ^* values) using the target profile, and uses the printer profile. color values (L ^* a ^* b ^* values) to print image data (CMYK values). The printer engine performs printing based on the print image data (CMYK values), thereby realizing colors that target the color sample.

As described above, according to the first embodiment, when the document image data includes the overlay reproduction setting, the fact that the reproduction setting is included is notified, so that the user's attention can be called. This makes it possible to prevent unintended color conversion when there is an overlapping object in the document image data.

Specifically, an image based on the document image data is displayed, and the display mode of the area corresponding to the reproduction setting in the image is set to a display mode different from that of the other areas. is displayed in a recognizable manner, making it easier for the user to focus on the area corresponding to the reproduction setting. By making the user aware of the existence of the reproduction settings, it is possible to prevent the acquisition of colors in which the reproduction settings are incorrect from the original image data, and reprinting that occurs due to output using the incorrectly corrected color conversion table. or readjustment.

In addition, when generating color conversion parameters, it is possible to select whether or not to use the information of the area corresponding to the reproduction settings of the read image data and the original image data. The color conversion parameters can be generated by excluding areas where there is a problem.

[Second embodiment]
Next, a second embodiment to which the present invention is applied will be described.
Since the image forming system in the second embodiment has the same configuration as the image forming system 100 shown in the first embodiment, FIGS. omitted. The configuration and processing that are characteristic of the second embodiment will be described below.

The control unit 11 acquires the difference between the read image data and the document image data when the document image data includes the overlay reproduction setting. A color difference can be used as the difference.

When the difference between the read image data and the document image data is equal to or greater than a predetermined value, the control unit 11 causes the display unit 12 to display an image based on the document image data, and displays the area corresponding to the reproduction setting in the image. The display mode is set to a display mode different from that of other areas.

Next, the operation of the PC 10 according to the second embodiment will be explained.
FIG. 6 is a flowchart showing second color conversion parameter generation processing executed by the PC 10. As shown in FIG. This processing is implemented by software processing in cooperation with the CPU 111 of the control unit 11 and the programs stored in the storage unit 15 .

Since the processing of steps S11 to S14 is the same as the processing of steps S1 to S4 of the first color conversion parameter generation processing (see FIG. 4), description thereof will be omitted.

In step S14, if the document image data includes the overlay reproduction setting (step S14; YES), the control unit 11 causes the display unit 12 to display a selection screen prompting the user to select whether the reproduction setting is valid or invalid. . The user selects whether to enable or disable the reproduction setting by operating the operation unit 13 (step S15).

Next, the control unit 11 rasterizes the document image data with the reproduction setting (valid or invalid) selected by the operation from the operation unit 13 to generate a rasterized image (step S16).

Next, the control unit 11 calculates the color difference between the rasterized image and the area corresponding to the reproduction setting of the read image data (step S17). Specifically, the control unit 11 uses the current target profile (before correction) to convert the area (CMYK values) corresponding to the reproduction settings of the rasterized image into color values (L ^* a ^* b ^* values). . The control unit 11 also uses the scanner profile to convert the area (RGB values) corresponding to the reproduction setting of the read image data into color values (L ^* a ^* b ^* values). The control unit 11 calculates the L ^* a ^* b ^* value obtained from the rasterized image of the document image data and the L ^* a ^* b ^* value obtained from the read image data for each position within the area corresponding to the reproduction setting. to calculate the color difference.

Next, the control unit 11 determines whether or not the color difference between the rasterized image and the area corresponding to the reproduction setting of the read image data is equal to or greater than a threshold value (step S18). For example, it is determined whether or not the color difference ΔEab between the rasterized image and the read image data is 2 or more. It may be determined whether the maximum value of color difference in the area corresponding to the reproduction setting is equal to or greater than the threshold, or whether the average value of color difference in the area corresponding to the reproduction setting is equal to or greater than the threshold. You may

If the color difference in the area corresponding to the reproduction setting is equal to or greater than the threshold (step S18; YES), the control section 11 determines that the reproduction setting selected in step S15 is incorrect (step S19). Here, the control unit 11 may cause the display unit 12 to display that the selected reproduction setting may be incorrect.

Next, the control unit 11 causes the display unit 12 to display an image based on the document image data (an image based on the selected reproduction setting), and the color difference in the area corresponding to the reproduction setting in the image is equal to or greater than the threshold. The display mode of the area is set to a display mode different from that of the other areas (step S20). For example, the control unit 11 blinks an area with a color difference equal to or greater than a threshold among the areas corresponding to the reproduction setting, or displays it in a color different from the surroundings.

The processes of steps S21 to S23 are the same as the processes of steps S6 to S8 of the first color conversion parameter generation process (see FIG. 4), so description thereof will be omitted. However, when generating the color conversion parameters, a rasterized image rasterized with the reproduction setting selected in step S15 is used as the document image data.

In step S18, if the color difference in the area corresponding to the reproduction setting is less than the threshold (step S18; NO), the control unit 11 determines that the reproduction setting selected in step S15 is correct (step S24 ). Here, the control unit 11 may cause the display unit 12 to display that the selected reproduction settings are considered to be correct.

In step S14, if the document image data does not include the overlay reproduction setting (step S14; NO), or after step S24, the control unit 11 sets the color conversion parameter based on the read image data and the document image data. is generated (step S25). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .
Note that if the process proceeds to step S25 after step S24, the rasterized image rasterized with the reproduction setting selected in step S15 is used as the document image data when generating the color conversion parameters.

After step S22, step S23, or step S25, the second color conversion parameter generation process ends.

As described above, according to the second embodiment, when the original image data includes the overlay reproduction setting, the color difference in the area corresponding to the reproduction setting in the image based on the original image data is the threshold value. Since the display mode of the above areas is different from the display mode of other areas, it is necessary to alert the user when the reproduction settings selected by the user are considered not to match the reproduction settings in the color sample. can be done. This makes it possible to prevent unintended color conversion when there is an overlapping object in the document image data.

In addition, when generating color conversion parameters, it is possible to select whether or not to use the information of the area corresponding to the reproduction settings of the read image data and the original image data. The color conversion parameters can be generated by excluding areas where there is a problem.

Note that the difference between the read image data and the document image data is not limited to the color difference, and one or both of the read image data and the document image data are converted to match the color space (color system) A difference between the same color values may be used.

[Third embodiment]
Next, a third embodiment to which the present invention is applied will be described.
Since the image forming system in the third embodiment has the same configuration as the image forming system 100 shown in the first embodiment, FIGS. omitted. The configuration and processing that are characteristic of the third embodiment will be described below.

When the document image data includes the overlay reproduction setting, the control unit 11 generates at least two images with changed reproduction settings for the document image data.
The control unit 11 causes the display unit 12 to display the generated at least two images, and sets the display mode of the area corresponding to the reproduction setting in the at least two images to a different display mode from the other areas.

In the third embodiment, the user selects the best one (the one whose color is closer to the color sample) of the at least two generated images.

Next, the operation of the PC 10 according to the third embodiment will be explained.
FIG. 7 is a flow chart showing the third color conversion parameter generation process executed by the PC 10. As shown in FIG. This processing is implemented by software processing in cooperation with the CPU 111 of the control unit 11 and the programs stored in the storage unit 15 .

Since the processing of steps S31 to S34 is the same as the processing of steps S1 to S4 of the first color conversion parameter generation processing (see FIG. 4), description thereof will be omitted.

In step S34, if the document image data includes a superposition reproduction setting (step S34; YES), the control unit 11 enables (ON) the reproduction setting, rasterizes the document image data, and produces a first rasterized image. is generated (step S35).
Further, the control unit 11 disables (OFF) the reproduction setting, rasterizes the document image data, and generates a second rasterized image (step S36).

Next, the control unit 11 causes the display unit 12 to display the first rasterized image and the second rasterized image, and sets the display mode of the area corresponding to the reproduction setting in each rasterized image to be different from the other areas. A display mode is set (step S37).

FIG. 8 is an example of the preview screen 122 displayed on the display unit 12. As shown in FIG. The preview screen 122 includes a first image display area 60, a second image display area 70, and an adjustment button B2.
In the first image display area 60, a first rasterized image obtained by rasterizing the document image data with the reproduction setting set to "valid" is displayed. The overprint area 61 in the first rasterized image has a display mode different from that of the other areas by superimposing dashed lines on the boundaries.
In the second image display area 70, a second rasterized image obtained by rasterizing the document image data with the reproduction setting set to "invalid" is displayed. The overprint area 71 in the second rasterized image has a display mode different from that of other areas by displaying a dashed line superimposed on the boundary of the overprint area 71 .

Further, by clicking each area of the first image display area 60 and the second image display area 70, the rasterized image corresponding to the clicked area can be selected.
The adjustment button B2 is pressed when instructing generation of color conversion parameters.

Next, the user selects either the first rasterized image or the second rasterized image by operating the operation unit 13 (step S38).
Specifically, on the preview screen 122 shown in FIG. 8, the user can select the first rasterized image in the first image display area 60, the second rasterized image in the second image display area 70, and a color sample (target output object). ), and the overprint areas 61 and 71 that are closer in appearance to the color sample (the one with the smaller color difference) are selected.
For example, by clicking the second image display area 70, a second rasterized image whose reproduction setting is invalid can be selected, and a frame 80 indicating the selection state is displayed around the second image display area 70. .

Next, the control unit 11 generates color conversion parameters based on the rasterized image (CMYK values) selected by operation from the operation unit 13 and the read image data (RGB values) (step S39). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .

Specifically, in the preview screen 122 shown in FIG. 8, either the first rasterized image in the first image display area 60 or the second rasterized image in the second image display area 70 is selected. , the user presses the adjustment button B2, the control unit 11 generates color conversion parameters.

In step S34, if the document image data does not include the overlay reproduction setting (step S34; NO), the control unit 11 generates color conversion parameters based on the read image data and the document image data (step S40). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .
After step S39 or step S40, the third color conversion parameter generation process ends.

As described above, according to the third embodiment, when the document image data includes the overlay reproduction settings, at least two images with changed reproduction settings are generated, and one of the at least two images is By setting the display mode of the area corresponding to the reproduction setting to a display mode different from that of the other areas, it is possible to present the user with at least two images with changed reproduction settings. By comparing these images with the color samples, the user can determine the reproduction settings in the color samples, so that unintended color conversion can be prevented when there are overlapping objects in the document image data.

Further, a threshold value is required to determine whether or not the reproduction settings match based on the color difference between the original image data and the read image data as in the second embodiment. In contrast, in the third embodiment, by presenting the user with at least two rasterized images whose reproduction settings have been changed, it is possible to compare the relative closeness to the color sample between the rasterized images. , which improves accuracy in determining reproduction settings.

[Modification 1]
Next, Modification 1 of the third embodiment will be described.
In modification 1, when generating at least two images to be displayed on the display unit 12, the control unit 11 generates at least two images by limiting the range of the area corresponding to the reproduction setting. Specifically, the control unit 11 generates at least two images with changed reproduction settings for the range of the area corresponding to the reproduction settings of the document image data.
Note that the rasterization range of the original image data is not limited to only the area corresponding to the reproduction setting. It is also possible to

For example, as shown in FIG. 9, rasterization is performed by changing the reproduction settings for a limited rectangular area 92 surrounding the area 91 corresponding to the reproduction settings of the original image data 90 .

Since the operation in Modification 1 is basically the same as the third color conversion parameter generation process (see FIG. 7), the differences from the third color conversion parameter generation process will be mainly described.
In step S35, the control unit 11 enables (ON) the reproduction setting, rasterizes the area corresponding to the reproduction setting of the document image data, and generates a first rasterized image.
In step S36, the control unit 11 disables (OFF) the reproduction setting, rasterizes the area corresponding to the reproduction setting of the document image data, and generates a second rasterized image.

In step S37, the control unit 11 causes the display unit 12 to display the first rasterized image and the second rasterized image. If the first rasterized image and the second rasterized image consist only of areas corresponding to the reproduction settings, it is not necessary to distinguishably display the areas corresponding to the reproduction settings. When the first rasterized image and the second rasterized image are composed of an area corresponding to the reproduction setting and a predetermined margin area, the display mode of the area corresponding to the reproduction setting in each rasterized image is A display mode different from that of the area may be used.

In step S39, the control unit 11 rasterizes the entire area of the document image data in accordance with the rasterized image reproduction setting (valid/invalid) selected in step S38, and the rasterized image (CMYK values) for the entire area and the read Color conversion parameters are generated based on the image data (RGB values).

According to Modification 1, since at least two images with changed reproduction settings are generated by limiting the range of the area corresponding to the reproduction settings of the document image data, the rasterization process can be speeded up.

[Modification 2]
Next, Modification 2 of the third embodiment will be described.
In Modified Example 2, when generating at least two images to be displayed on the display unit 12, the control unit 11 includes the range of the area corresponding to the reproduction setting, and aligns the read image data and the document image data. At least two images are generated by limiting the range of the area including the feature points used for (associating). The control unit 11 uses feature points on the image data when aligning the read image data and the document image data.

FIG. 10 is a cutout of a portion 93 of the document image data. For example, positions 95 to 98 detected as corners on the boundary line of the region 94 corresponding to the reproduction setting are used as feature points. Such feature points are necessary when generating the color conversion parameters and associating the L ^* a ^* b ^* values obtained from the read image data with the CMYK values of the document image data.

If the "Range of the area corresponding to the reproduction setting" contains the feature points required for alignment, limit the reproduction setting to the "Range of the area corresponding to the reproduction setting" of the original image data. At least two modified images may be generated.
If the "Range of the area corresponding to the reproduction setting" does not include the feature points required for alignment, the "Range of the area corresponding to the reproduction setting" is expanded to include the feature points. At least two images with different reproduction settings may be generated by limiting the target range to the processing target range of the document image data.
The operation in Modification 2 is the same as that in Modification 1, except that the rasterization range is different.

According to Modified Example 2, at least two images with different reproduction settings are generated by limiting the range of the area including the feature points used for alignment of the document image data with the read image data, so alignment can be performed with high accuracy. , the speed of the rasterization process can be increased.

[Fourth embodiment]
Next, a fourth embodiment to which the present invention is applied will be described.
The image forming system according to the fourth embodiment has the same configuration as the image forming system 100 shown in the first embodiment, so FIGS. omitted. The configuration and processing characteristic of the fourth embodiment will be described below.

When the document image data includes the overlay reproduction setting, the control unit 11 generates at least two images with changed reproduction settings for the document image data.
The control unit 11 acquires the difference from the read image data for each of at least two images.
The control unit 11 generates color conversion parameters based on the read image data and the image corresponding to the reproduction setting with the smallest difference from the read image data.

Next, the operation of the PC 10 according to the fourth embodiment will be explained.
FIG. 11 is a flowchart showing fourth color conversion parameter generation processing executed by the PC 10. FIG. This processing is implemented by software processing in cooperation with the CPU 111 of the control unit 11 and the programs stored in the storage unit 15 .

Since the processing of steps S41 to S46 is the same as the processing of steps S31 to S36 of the third color conversion parameter generation processing (see FIG. 7), description thereof will be omitted.

After step S46, the control unit 11 calculates the color difference between the first rasterized image generated with the reproduction setting enabled and the area corresponding to the reproduction setting of the read image data, and calculates the color difference of the area corresponding to the reproduction setting of the read image data. A color difference between the second rasterized image and the area corresponding to the reproduction setting of the read image data is calculated (step S47). The color difference calculation method is the same as step S17 of the second color conversion parameter generation process (see FIG. 6).

Next, the control unit 11 adopts the reproduction setting of the rasterized image having a smaller color difference from the read image data in the area corresponding to the reproduction setting (step S48). Here, the control unit 11 may display on the display unit 12 whether the adopted reproduction setting is valid or invalid.

Next, the control unit 11 generates color conversion parameters based on the rasterized image (CMYK values) with the smaller color difference and the read image data (RGB values) (step S49). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .

In step S44, if the document image data does not include the overlay reproduction setting (step S44; NO), the control unit 11 generates color conversion parameters based on the read image data and the document image data (step S50). The method of correcting the color conversion table (target profile) is as described with reference to FIG. Control unit 11 updates the target profile in storage unit 15 .
After step S49 or step S50, the fourth color conversion parameter generation process ends.

As described above, according to the fourth embodiment, when the document image data includes the overlay reproduction setting, at least two images with different reproduction settings are generated, and the difference from the read image data is the largest. Since the color conversion parameters are generated based on the image corresponding to the small reproduction setting and the read image data, unintended color conversion can be prevented when there is an overlapping object in the document image data.

Further, in the fourth embodiment, by calculating the color difference between at least two rasterized images whose reproduction settings are changed and the read image data, and adopting the reproduction setting with the smallest color difference, the color of the color sample is automatically calculated. You can choose a reproduction setting that is close to , improving accuracy.

In the fourth embodiment, as in the first and second modifications of the third embodiment, when at least two images are generated from the document image data, the range of the area may be limited. good. However, in step S49, the control unit 11 rasterizes the entire area of the original image data according to the reproduction setting (valid/invalid) of the rasterized image having a smaller color difference from the read image data, and produces a rasterized image for the entire area ( CMYK values) and read image data (RGB values) to generate color conversion parameters.

It should be noted that the description in each of the above embodiments is an example of the color conversion parameter generation device according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of each unit that constitutes the device can be changed as appropriate without departing from the scope of the present invention.
For example, characteristic processing in each embodiment may be combined.

Moreover, each function for carrying out the present invention may be divided into a plurality of devices, or may be installed in one device. For example, the functions executed by the PC 10 in each of the above embodiments may be installed in the printer 30 .

In addition, the color system (CMYK) of the document image data, the color system (RGB) of the read image data of the scanner 20, the color system (L ^* a ^* b ^* ) of the color values, and the image used in printing by the printer 30 The data color system (CMYK) and the like are not limited to the above examples.

The computer-readable medium storing the program for executing each process is not limited to the above example, and a portable recording medium such as a CD-ROM can also be applied. Further, a carrier wave may be applied as a medium for providing program data via a communication line.

10 PCs
11 control unit 12 display unit 13 operation unit 14 communication unit 15 storage unit 20 scanner 30 printer 50 image display area 51 overprint area 60 first image display area 61 overprint area 70 second image display area 71 overprint area 100 image formation system

Claims (15)

Acquire the read image data of the color sample,
obtaining document image data corresponding to the color sample;
A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the document image data based on the read image data and the document image data,
The control unit
determining whether the original image data includes reproduction settings for overlapping objects;
notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting ;
acquiring a difference between the read image data and the document image data when the document image data includes the reproduction setting;
When the difference is equal to or greater than a predetermined value, an image based on the document image data is displayed on the display unit, and the display mode of the area corresponding to the reproduction setting in the image is set to a different display mode from the other areas. and a color conversion parameter generation device. Acquire the read image data of the color sample,
obtaining document image data corresponding to the color sample;
A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the document image data based on the read image data and the document image data,
The control unit
determining whether the original image data includes reproduction settings for overlapping objects;
notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
selection means for selecting whether or not to use information of areas corresponding to the reproduction settings of the read image data and the document image data when generating the color conversion parameters;
The control section is a color conversion parameter generation device for generating the color conversion parameters based on the selection result of the selection means. When the document image data includes the reproduction setting, the control unit causes the display unit to display an image based on the document image data, and changes the display mode of the area corresponding to the reproduction setting in the image to other settings. 3. The color conversion parameter generation device according to claim 2, wherein the display mode is different from that of the area of . Acquire the read image data of the color sample,
obtaining document image data corresponding to the color sample;
A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the document image data based on the read image data and the document image data,
The control unit
determining whether the original image data includes reproduction settings for overlapping objects;
notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
generating at least two images in which the reproduction settings are changed for the document image data, when the document image data includes the reproduction settings;
A color conversion parameter generation device that displays the at least two images on a display unit, and sets the display mode of an area corresponding to the reproduction setting in the at least two images to a display mode different from that of other areas. Acquire the read image data of the color sample,
obtaining document image data corresponding to the color sample;
A color conversion parameter generation device comprising a control unit for generating color conversion parameters for color conversion of the document image data based on the read image data and the document image data,
The control unit
determining whether the original image data includes reproduction settings for overlapping objects;
notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
generating at least two images in which the reproduction settings are changed for the document image data, when the document image data includes the reproduction settings;
obtaining a difference from the read image data for each of the at least two images;
A color conversion parameter generating device for generating the color conversion parameters based on the image corresponding to the reproduction setting with the smallest difference and the read image data. 6. The color conversion parameter generation device according to claim 4 , wherein the control unit generates the at least two images by limiting the area range corresponding to the reproduction setting. 7. The color conversion parameter generation according to claim 6 , wherein the control unit generates the at least two images by limiting the range of an area including feature points used for alignment between the read image data and the document image data. Device. reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. A color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating,
determining by the control unit whether or not the document image data includes reproduction settings for overlapping objects;
a step of notifying that the document image data includes the reproduction setting by the control unit when the original image data includes the reproduction setting;
obtaining, by the control unit, a difference between the read image data and the document image data when the document image data includes the reproduction setting;
The control unit causes the display unit to display an image based on the document image data when the difference is equal to or greater than a predetermined value, and changes the display mode of the area corresponding to the reproduction setting in the image to another area. A step of making a display mode different from
A method for generating color conversion parameters, including reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. A color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating,
determining by the control unit whether or not the document image data includes reproduction settings for overlapping objects;
a step of notifying that the document image data includes the reproduction setting by the control unit when the original image data includes the reproduction setting;
a step of determining, by the control unit, a result of selection by a selection means as to whether or not to use information of areas corresponding to the reproduction settings of the read image data and the document image data when generating the color conversion parameters; and,
a step of generating the color conversion parameter by the control unit based on the selection result of the selection means;
A method for generating color conversion parameters, including reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. A color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating,
determining by the control unit whether or not the document image data includes reproduction settings for overlapping objects;
a step of notifying that the document image data includes the reproduction setting by the control unit when the original image data includes the reproduction setting;
a step of generating at least two images with the reproduction settings changed for the document image data by the control unit when the document image data includes the reproduction settings;
causing the control unit to display the at least two images on the display unit, and setting the display mode of the area corresponding to the reproduction setting in the at least two images to a display mode different from that of other areas;
A method for generating color conversion parameters, including reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. A color conversion parameter generation method in a color conversion parameter generation device comprising a control unit for generating,
determining by the control unit whether or not the document image data includes reproduction settings for overlapping objects;
a step of notifying that the document image data includes the reproduction setting by the control unit when the original image data includes the reproduction setting;
a step of generating at least two images with the reproduction settings changed for the document image data by the control unit when the document image data includes the reproduction settings;
obtaining a difference between the read image data and the at least two images by the control unit;
a step of generating the color conversion parameter by the control unit based on the image corresponding to the reproduction setting with the smallest difference and the read image data;
A method for generating color conversion parameters, including reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. In the computer of the color conversion parameter generation device to generate,
determining whether the original image data includes reproduction settings for overlapping objects;
a step of notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
obtaining a difference between the read image data and the document image data when the document image data includes the reproduction setting;
When the difference is equal to or greater than a predetermined value, an image based on the document image data is displayed on the display unit, and the display mode of the area corresponding to the reproduction setting in the image is set to a different display mode from the other areas. and
program to run the reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. In the computer of the color conversion parameter generation device to generate,
determining whether the original image data includes reproduction settings for overlapping objects;
a step of notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
a step of judging a result of a selection by a selection means as to whether or not to use information of an area corresponding to the reproduction setting of the read image data and the document image data when generating the color conversion parameters;
generating the color conversion parameters based on the selection result of the selection means;
program to run the reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. In the computer of the color conversion parameter generation device to generate,
determining whether the original image data includes reproduction settings for overlapping objects;
a step of notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
generating at least two images for the document image data with the reproduction settings changed, if the document image data includes the reproduction settings;
a step of displaying the at least two images on a display unit, and setting a display mode of a region corresponding to the reproduction setting in the at least two images to a display mode different from that of other regions;
program to run the reading image data of a color sample is obtained, document image data corresponding to the color sample is obtained, and based on the read image data and the document image data, color conversion parameters for color conversion of the document image data are determined. In the computer of the color conversion parameter generation device to generate,
determining whether the original image data includes reproduction settings for overlapping objects;
a step of notifying that the original image data includes the reproduction setting when the original image data includes the reproduction setting;
generating at least two images for the document image data with the reproduction settings changed, if the document image data includes the reproduction settings;
obtaining a difference from the read image data for each of the at least two images;
generating the color conversion parameters based on the image corresponding to the reproduction setting with the smallest difference and the read image data;
program to run the

Images