JP6769271B2 - Color conversion control program and color conversion control method - Google Patents

Description

The present invention relates to a color conversion control program and a color conversion control method, and more particularly to a color conversion control program and a color conversion control method for controlling color conversion for outputting a color verification chart.

When using a new paper type, the printer performs color verification on the print color. In this color verification, for example, a color verification chart is output without performing color conversion, and a printer profile is created using the colorimetric values obtained by measuring the output color verification chart with a colorimeter. Then, after performing color conversion using the created printer profile, a color verification chart is output, and color verification is performed using the colorimetric value obtained by measuring the output color verification chart with a colorimeter. If the color verification result fails, perform color correction using the color correction function of the printer, output the color verification chart again, and output / color measurement of the color verification chart until the color verification result passes. / Repeat color correction.

Here, when performing color management for a large number of printers located at a large number of bases, it is complicated to output a color verification chart and measure colors for each printer. Therefore, colors are used using an application on the cloud. Cloud color management is performed to centrally manage. In order to output this color verification chart, it is necessary to apply the ICC (International Color Consortium) profile to perform color conversion, but color conversion settings (designated output of the ICC profile) cannot be set from the application side, such as printers of other companies. For the printer, it is necessary to perform color conversion of the color verification chart on the application side.

As a technique related to such cloud color management, for example, the following Patent Document 1 describes an image processing device that performs a print simulation via a network, a color printer on the network as a target of the print simulation, and a preview. A device selection means for selecting a color monitor on the network to be displayed, a setting means for setting observation conditions for print output of the target printer, and observation conditions for the monitor for preview display, and a color of the preview display. The profile selection means for selecting the profile required for the matching process and setting the selected profile to the target printer, and the profile set to the target printer, regarding the information regarding the observation conditions of the print output and the observation conditions of the monitor. The embedding means for embedding the information, the communication means for transmitting the image data to be color-matched to the target printer, and the communication means for receiving the image data to be color-matched according to the selected profile from the target printer. A configuration including an output means for displaying an image based on image data on the printer for preview display is disclosed.

Japanese Unexamined Patent Publication No. 2005-142769

When performing the above-mentioned cloud color management, in the case of a printer whose color conversion settings can be set from the application side, such as a printer manufactured by a company that develops an application (in-house printer), the ICC profile specified by the application is applied locally. Color conversion of the color verification chart can be performed using the CMM (Color Management Module) on the (printer) side, but for printers that cannot be set for color conversion from the application side, such as printers of other companies, specify the ICC profile. Therefore, the color conversion of the color verification chart is performed using the CMM on the cloud (application) side.

On the other hand, when printing based on a job (actual output), the profile set by the printer is usually applied and color conversion is performed using the CMM of the own device. Therefore, in other companies' printers, color verification and actual output are performed. You will be using a different CMM. Here, in color conversion using CMM, there are errors due to interpolation and errors due to settings not specified by the ICC profile (retention of smear plate, pure color step, removal of turbidity of pure color gradation, etc.), so colors are used using different CMMs. When the conversion is performed, there arises a problem that the color conversion results do not match between the time of color verification and the time of actual printing.

To solve this problem, a method of performing color conversion using the CMM on the cloud (application) side not only during color verification but also during actual output can be considered, but with this method, the cloud application can be used even during actual output. Jobs must be sent, the application must perform color conversion, and the image data after color conversion must be sent to the printer, which increases print performance due to increased data transfer time and color conversion processing time. ..

The present invention has been made in view of the above problems, and a main object thereof is at the time of actual output and at the time of color verification even when outputting to a printer having a CMM different from the system for performing color verification. It is an object of the present invention to provide a color conversion control program and a color conversion control method capable of obtaining similar color conversion results.

One aspect of the present invention is a color conversion control program that operates in a device that performs color verification by outputting a color verification chart to a printer having a CMM that performs color conversion, and is an output target of the color verification chart to the device. The first process of acquiring the information of the printer of the above and specifying the CMM of the printer to be output, and when the CMM of the own device and the CMM of the printer to be output are different, the error of the color conversion due to the difference of the CMM is acquired. The second process, the third process of setting the ICC profile, and the fourth process of applying the set ICC profile and performing color conversion on the image data of the color verification chart using the CMM of the own device. , The fifth process for correcting the error of the color conversion, the color conversion, and the correction were performed on the image data of the color verification chart which was subjected to the color conversion with reference to the correction LUT stored in advance. It is characterized in that the sixth process of transmitting the image data of the color verification chart to the printer to be output is executed.

One aspect of the present invention is a color conversion control method in a printing system including a printer having a CMM that performs color conversion and a device that prints a color verification chart on the printer to perform color verification. , When the first process of acquiring the information of the output target printer of the color verification chart and specifying the CMM of the output target printer and the CMM of the own device and the CMM of the output target printer are different, the CMM. The second process for acquiring the error of color conversion due to the difference between the printers, the third process for setting the ICC profile, and the set ICC profile are applied, and the image of the color verification chart is applied using the CMM of the own device. With reference to the fourth process of performing color conversion on the data and the correction LUT stored in advance, the image data of the color verification chart on which the color conversion has been performed is corrected for the error of the color conversion. The fifth process and the sixth process of transmitting the image data of the color verification chart to which the color conversion and the correction have been performed to the printer to be output are executed, and the printer to be output is the color verification chart. After receiving the image data of the above, the color verification chart is printed based on the received image data without performing color conversion.

According to the color conversion control program and the color conversion control method of the present invention, even when outputting to a printer having a CMM different from the system for performing color verification, the same color conversion is performed at the time of actual output and at the time of color verification. You can get the result.

The reason is that the color conversion control program that operates in the device that outputs the color verification chart to the printer and performs color verification acquires an error due to the difference in CMM when outputting to a printer that has a CMM different from its own CMM. Then, after applying the set ICC profile and performing color conversion using its own CMM, the image data of the color verification chart is obtained by correcting the error due to the difference in CMM by referring to the correction LUT created in advance. This is because the control is performed to generate and output the generated image data to the printer.

It is a schematic diagram explaining the color conversion control method which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the printing system which concerns on one Example of this invention. It is a schematic diagram which shows another example of the printing system which concerns on one Example of this invention. It is a block diagram which shows the structure of the printer which concerns on one Example of this invention. It is a block diagram which shows the structure of the color verification system which concerns on one Example of this invention. It is a flowchart which shows the operation of the color verification system which concerns on one Example of this invention.

As shown in the background technology, when color management of a large number of printers located at a large number of bases is performed, cloud color management is performed in which color management is centrally performed using an application on the cloud. It is necessary to apply an ICC profile in order to output a color verification chart, but in the case of a printer such as a printer of another company whose color conversion settings cannot be set from the application side, the ICC profile cannot be specified, so the cloud (application) The color conversion of the color verification chart will be performed using the CMM on the side.

Here, when performing color conversion using the CMM on the cloud side at the time of color verification and performing color conversion using the CMM on the local side at the time of actual output, a different CMM will be used, but the CMM was used. In color conversion, there are interpolation errors and errors due to settings not specified by the ICC profile, so if color conversion is performed using different CMMs, there is a problem that the color conversion results do not match between color verification and actual printing. Occurs. To solve this problem, a method of performing color conversion using CMM on the cloud side can be considered even during actual output, but this method increases the data transfer time and color conversion processing time between the local and cloud. , Printing performance is degraded.

This problem will be described with reference to FIG. The left side of FIG. 1 schematically shows the operation of an application (color verification application) operating on the cloud. The color verification application can set an ICC profile, and the set ICC profile is applied to perform color conversion. I have a CMM1 to do. The center of the figure schematically shows the operation of a printer that outputs prints. Printer 1 is an in-house printer that can set color conversion from the application side, and printer 2 is a printer of another company that cannot set color conversion from the application side. ..

The printer 1 has the same CMM1 as the color verification application, and when the color verification application sets the color conversion setting (designation of the ICC profile) for the printer 1 and outputs the chart image, the printer 1 sets the color conversion setting. The ICC profile specified according to the above is applied, color conversion is performed using CMM1 of the printer 1, and chart 1a is output (the same applies when processing this job). Further, when the ICC profile is applied on the color verification application side and the image of the chart subjected to the color conversion using the CMM1 of the color verification application is output to the printer 1, the printer 1 does not perform the color conversion and the chart 1b Is output. Since the same ICC profile is applied to the chart 1a and the chart 1b and the color conversion is performed using the same CMM, the result of color measurement by the colorimeter is the same. That is, in the case of an in-house printer, the same result can be obtained regardless of which CMM is used.

On the other hand, the printer 2 has a CMM 2 different from the color verification application, and the color verification application cannot set the color conversion for the printer 2. Therefore, when the chart image is output to the printer 2 without performing the color conversion on the color verification application side, the printer 2 applies the ICC profile set according to the color conversion setting of the own device, and the color conversion is performed using the CMM 2. Is performed to output chart 2a (the same applies when processing this job). Further, when the ICC profile is applied on the color verification application side and the image of the chart subjected to the color conversion using the CMM 1 is output to the printer 2, the printer 2 outputs the chart 2b without performing the color conversion. In this case, since the color conversion is performed using different CMMs for the chart 2a and the chart 2b, an error occurs due to the difference in the CMM, and the color conversion at the time of color verification is different from the color conversion performed in this job. As a result, the color verification application cannot perform color conversion all at once.

Therefore, in one embodiment of the present invention, when color conversion settings such as an ICC profile cannot be performed from the color verification application side on the cloud and output to a printer having a CMM different from the color verification application, The color verification application applies an ICC profile, performs color conversion using the CMM of the color verification application, creates image data corrected for errors due to differences in CMM, and outputs the image data without color conversion. Instruct the printer to do so.

Specifically, as shown by the thick line in FIG. 1, the device value of the image data color-converted using the CMM2 of the printer 2 (or the color measurement value obtained by measuring the color of the chart 2a printed based on the image data). , The device value of the image data color-converted using CMM1 of the color verification application (or the color measurement value obtained by measuring the color of the chart 2b printed based on the image data), and the correction LUT describing the difference. Is created. Then, at the time of color verification, after performing color conversion using CMM1 of the color verification application, the error due to the difference in CMM is corrected by referring to the above correction LUT, and the image data of the corrected chart is output to the printer 2. Then, the printer 2 outputs the chart 2c without performing the color conversion. In this case, the chart 2a and the chart 2c are color-converted using different CMMs, but since the error due to the difference in CMMs is eliminated by the correction, the printer 2 is color-converted by the color verification application. The same result as the case of color conversion with.

As a result, even for printers that do not have connectivity with color verification applications, such as printers of other companies (color conversion settings cannot be set from the color verification application side), color conversion was performed from the color verification application under conditions similar to this job. A color verification chart can be output. As a result, color verification can be performed using a color verification application, and color management can be easily performed even in a system equipped with a large number of printers located at a large number of bases. In addition, rasterization and color conversion of this job, which takes time for data transfer and processing, can be performed at high speed on the local side, and color verification can be performed centrally on the cloud side using a color verification application, so it is unified with print performance. It is possible to achieve both convenience of management.

In order to explain one embodiment of the present invention in more detail, the color conversion control program and the color conversion control method according to the embodiment of the present invention will be described with reference to FIGS. 2 to 6. 2 and 3 are schematic views showing a configuration example of the printing system of this embodiment, FIG. 4 is a block diagram showing a configuration of a printer, and FIG. 5 is a block diagram showing a configuration of a color verification system. .. Further, FIG. 6 is a flowchart showing the operation of the color verification system of this embodiment.

As shown in FIG. 2, the printing system 10 of this embodiment includes a plurality of printers 20, a controller 30, a color verification system 40, a client device 50, a colorimeter 60, and the like. These are connected via a communication network 70 such as LAN (Local Area Network) or WAN (Wide Area Network) defined by standards such as Ethernet (registered trademark), Token Ring, and FDDI (Fiber-Distributed Data Interface). There is. The client device 50 and the colorimeter 60 can also be connected by a dedicated line such as a PCI (Peripheral Components Interconnect) connection.

Each of the plurality of printers 20 receives image data from the controller 30, the color verification system 40, or the client device 50, forms an image based on the image data on paper, and outputs the image data. The plurality of printers 20 are managed in groups by the controller 30, the color verification system 40, or the client device 50, and the printers 20 belonging to the same group can be the target of the color conversion control of this embodiment.

The controller 30 performs image processing such as rasterization, color conversion, and screening on the job issued by the client device 50, and transfers the image data after the image processing to the printer 20 which is group-managed.

The color verification system 40 receives an instruction from the client device 50, outputs image data of the color verification chart to the group-managed printer 20, controls color measurement of the color verification chart, and processes for displaying the result of the color verification. I do.

The client device 50 issues a job for giving a print instruction to the controller 30 by using a printer driver or dedicated software. Further, the client device 50 instructs the color verification system 40 to perform color verification, and displays the result of the color verification.

The colorimeter 60 is a spectrophotometric colorimeter that can measure each wavelength of light, is connected to the client device 50, measures the color verification chart output by the printer 20, and measures the color. The value (L * a * b * value, XYZ value, etc.) is output. The colorimeter 60 may be controlled by using a dedicated application installed in the client device 50, or may be directly controlled by the color verification system 40.

Note that FIG. 2 is an example of the printing system 10 of this embodiment, and its configuration can be changed as appropriate. For example, in FIG. 2, the printing system 10 is provided with the colorimeter 60, but when the color verification chart is measured using the in-line colorimeter provided in the printer 20, the colorimeter 60 is omitted. Can be done. Further, as shown in FIG. 3, the controller 30 may be configured to be built in the printer 20. Hereinafter, the printer 20 (printer incorporating the controller 30) and the color verification system 40 in the configuration of FIG. 3 will be described in detail.

[Printer]
The printer 20 is an MFP (Multi-Functional Peripherals), a single-function printer, or the like. A plurality of printers 20 included in the printing system 10 can be managed in groups, and the printers 20 belonging to the same group are the colors of the present embodiment. It can be the target of conversion control. As shown in FIG. 4A, the printer 20 includes a control unit 21, a storage unit 25, a network I / F unit 26, a display operation unit 27, an image processing unit 28, a print processing unit 29, and the like.

The control unit 21 is composed of a CPU (Central Processing Unit) 22 and a memory such as a ROM (Read Only Memory) 23 and a RAM (Random Access Memory) 24, and the CPU 22 stores a control program stored in the ROM 23 and the storage unit 25. The operation of the entire printer 20 is controlled by expanding it into the RAM 24 and executing it.

The storage unit 25 is composed of an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like, and stores a program for the CPU 22 to control each unit, information on the processing function of the own device, an ICC profile, and the like.

The network I / F unit 26 is composed of a NIC (Network Interface Card), a modem, or the like, connects the printer 20 to the communication network 70, and enables data communication with the color verification system 40, the client device 50, and the like.

The display operation unit 27 is a touch panel or the like provided with a pressure-sensitive operation unit (touch sensor) in which transparent electrodes are arranged in a grid pattern on the display unit such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. , Various screens related to printing processing, the results of color verification performed by the color verification system 40, and the like are displayed, and various operations related to printing and color correction instructions for the results of color verification are enabled.

The image processing unit 28 includes a RIP (Raster Image Processor) unit and the like, interprets the print language of the job issued by the client device 50, performs rasterization processing, and instructs CMM 21b, which will be described later, to perform color conversion.

The print processing unit (print engine) 29 executes print processing based on the image data transferred from the CMM 21b, and outputs an actual image. The printing processing unit 29 irradiates the photoconductor drum charged by the charging device with light corresponding to the image from the exposure device to form an electrostatic latent image, adheres the toner charged by the developing device, and develops the image. The toner image is first transferred to a transfer belt, secondarily transferred from the transfer belt to paper, and further, a process of fixing the toner image on the paper is performed by a fixing device. In addition, the print processing unit 29 includes an in-line scanner and an in-line colorimeter, if necessary.

As shown in FIG. 4B, the control unit 21 also functions as an ICC profile setting unit 21a, CMM21b, and the like.

The ICC profile setting unit 21a sets the ICC profile (target profile and printer profile, or device link profile) applied by the CMM 21b at the time of color conversion.

The CMM21b applies the set ICC profile (target profile and printer profile, or device link profile) to the device value (CMYK) of the image data (for example, the image data of the color verification chart) received from the color verification system 40. The value) is color-converted so as to match the target color space, and the image data after the color conversion is transferred to the print processing unit 29. The CMM 21b can be set to an operation mode in which color conversion is performed (color conversion ON) and an operation mode in which color conversion is not performed (color conversion OFF), and the color verification system 40 instructs the output with color conversion OFF. In this case, the image data is transferred to the print processing unit 29 without performing color conversion.

[Color verification system]
The color verification system 40 sets and manages a plurality of printers 20 as a group of printers in advance, instructs the plurality of printers 20 to print a color verification chart, and performs color verification based on the color measurement result of the color verification chart. Do. As shown in FIG. 5A, the color verification system 40 includes a control unit 41, a storage unit 45, a network I / F unit 46, and if necessary, a display unit and an operation unit.

The control unit 41 is composed of a CPU 42 and a memory such as a ROM 43 or a RAM 44. The CPU 42 expands a control program stored in the ROM 43 or the storage unit 45 into the RAM 44 and executes the operation of the entire color verification system 40. Control.

The storage unit 45 is composed of an HDD, SSD, or the like, and is for correcting an error due to a difference in a program for the CPU 42 to control each unit, information on the processing function of the own device, an ICC profile, image data of a color verification chart, and a CMM. The correction LUT and the like are stored.

The network I / F unit 46 is composed of a NIC, a modem, or the like, connects the color verification system 40 to the communication network 70, and enables data communication with the printer 20, the client device 50, the colorimeter 60, and the like.

As shown in FIG. 5B, the control unit 41 also functions as an output instruction unit 41a, an ICC profile setting unit 41b, a CMM 41c, a printer type determination unit 41f, a CMM difference acquisition unit 41g, a color verification unit 41h, and the like. ..

The output instruction unit 41a transmits the image data of the color verification chart to the printer 20 to be output among the group-managed printers 20 according to the instruction of the client device 50, and instructs the output of the color verification chart. If the print interface (protocol) of the printer 20 is unknown, the output of the color verification chart is instructed by outputting the data to the hot folder. When the color verification system 40 performs color conversion (or correction of error due to color conversion and CMM difference), the output target printer 20 is subjected to color conversion color (or error due to color conversion and CMM difference). The image data that has been corrected) is transmitted, and output is instructed in the operation mode (color conversion OFF) that does not perform color conversion. The output target printer 20 is a printer that can set color conversion, and color verification is performed. When the system 40 does not perform color conversion, the output target printer 20 is instructed to set the color conversion, the image data without the color conversion is transmitted, and the operation mode (color conversion ON) for performing the color conversion is set. Instruct the output of.

The ICC profile setting unit 41b sets the ICC profile (target profile and printer profile, or device link profile) applied by the CMM 41c at the time of color conversion.

The CMM 41c is composed of a color conversion unit 41d and a CMM difference correction unit 41e.

The color conversion unit 41d applies the ICC profile (target profile and printer profile, or device link profile) set by the ICC profile setting unit 41b, and targets the device value (CMYK value) of the image data of the color verification chart. Perform color conversion to match the color space.

When the CMM difference correction unit 41e determines that the error due to the CMM difference (color conversion error) is equal to or greater than a predetermined value, the CMM difference acquisition unit 41g described later refers to the correction LUT described later. The color conversion unit 41d corrects the image data of the color verification chart that has undergone color conversion to eliminate the error due to the difference in CMM.

The printer type determination unit 41f acquires the printer information of the group-managed printer 20, and determines whether the printer 20 to be output of the color verification chart is a printer capable of color conversion setting (profile designation output). Further, the printer type determination unit 41f specifies the CMM 21b possessed by the printer 20 to be output of the color verification chart.

The CMM difference acquisition unit 41g applies the same profile, and when color conversion is performed using the CMM 41c of its own device and the CMM 21b of the printer 20, the device value of the image data or the printed matter printed based on the image data is printed. The error (color conversion error) that occurs in the color measurement value obtained by color measurement is acquired, and the error due to the difference in CMM is greater than or equal to a predetermined value (for example, average ΔE> 0.5 or maximum ΔE> 2.0). Etc.). Further, the CMM difference acquisition unit 41g creates a correction LUT that describes a correction amount for correcting the acquired error. When comparing the output image data, create a correction LUT in which the correction amount is described by the device value (CMYK value), and when comparing the color measurement values obtained by measuring the output color verification chart. , Create a correction LUT in which the correction amount is described by the color measurement value (L * a * b * value).

The color verification unit 41h acquires the color measurement value of the output color verification chart from the colorimeter 60, calculates the color difference from the target color space, performs color verification, and obtains the color verification result from the client device 50, etc. Notify to.

The output instruction unit 41a, ICC profile setting unit 41b, CMM 41c, printer type determination unit 41f, CMM difference acquisition unit 41g, and color verification unit 41h may be configured as hardware, or the control unit 41 may be configured as an output instruction unit. 41a, ICC profile setting unit 41b, CMM 41c, printer type determination unit 41f, CMM difference acquisition unit 41g, color verification unit 41h (in particular, output instruction unit 41a, ICC profile setting unit 41b, CMM 41c, printer type determination unit 41f, CMM difference) It may be configured as a color verification application (color conversion control program) that functions as the acquisition unit 41g), and the CPU 42 may execute the color conversion control program.

Note that FIGS. 2 to 5 are examples of the printing system 10 of this embodiment, and the configuration and control of each device can be changed as appropriate. For example, the color verification application (color conversion control program) operated by the control unit 41 of the color verification system 40 may be a web application on the cloud, an on-premises type web application, or a local application.

Hereinafter, the color conversion control of the color verification system 40 of this embodiment will be described. First, prior to the color conversion control, a procedure for creating a correction LUT used for correction for eliminating an error due to a difference in CMM will be described.

When the client device 50 instructs to output the color verification chart, the ICC profile setting unit 41b of the color verification system 40 sets the ICC profile, and the color conversion unit 41d of the CMM 41c applies the set ICC profile. Color conversion is performed, and the image data after color conversion is transmitted to the printer 20 to instruct printing of the color verification chart. Further, the printer type determination unit 41f determines whether the printer 20 to be output is a printer capable of setting color conversion, and if the printer cannot set color conversion, does not set the ICC profile and perform color conversion. The image data is transmitted to the printer 20 to instruct printing of the color verification chart.

When the printer 20 receives the image data after the color conversion, the print processing unit 29 prints the first color verification chart based on the image data and receives the image data without the color conversion. The control unit 21 (ICC profile setting unit 21a) sets the ICC profile, the control unit 21 (CMM21b) applies the set ICC profile to perform color conversion, and the print processing unit 29 performs color conversion. A second color verification chart is printed based on the later image data. Then, the client device 50 controls the colorimeter 60 to measure the color of the first color verification chart and the second color verification chart to acquire the colorimetric value, and the acquired colorimetric value is the color verification system. Notify 40.

The CMM difference acquisition unit 41g of the color verification system 40 compares the color measurement values of the first color verification chart and the second color verification chart, and compares the difference between the CMM 41c of its own device and the CMM 21b of the printer 20 with the first color verification chart. A correction LUT is created by associating the difference between the color measurement value of the color verification chart and the color measurement value of the second color verification chart, and the created correction LUT is stored in the storage unit 45 or the like. When creating the device value correction LUT, the CMM difference acquisition unit 41g of the color verification system 40 acquires the image data obtained by the CMM 21b of the printer 20, and the CMM 41c of its own device performs the color conversion. The difference between the device value of the image data and the device value of the image data to which the CMM21b of the printer 20 has undergone color conversion may be described in the correction LUT.

A case where the color verification system 40 performs color conversion control after the correction LUT is created by the above procedure will be described. The CPU 42 executes the processing of each step shown in the flowchart of FIG. 6 by expanding and executing the color conversion control program stored in the ROM 43 or the storage unit 45 in the RAM 44.

First, the control unit 41 (printer type determination unit 41f) acquires the printer information of the printer 20 to be output among the plurality of printers 20 managed in the group (S101). Even if this printer information is acquired from a DB on the cloud (for example, MIB (Management Information Base) information published by a network device managed by SNMP (Simple Network Management Protocol) to notify the outside of its own status). Alternatively, the user may be able to register.

Next, the control unit 41 (printer type determination unit 41f) determines, based on the acquired printer information, whether the printer 20 to be output of the color verification chart is a printer that can perform color conversion settings from the color verification system 40. (S102), the CMM 21b possessed by the printer 20 to be output of the color verification chart is specified. When the output target printer 20 is a printer capable of color conversion setting (Yes in S102), the control unit 41 (output instruction unit 41a) instructs the printer 20 to perform color conversion setting (S103), and displays the color verification chart. The image data is transmitted and the output in the color conversion ON (operation mode in which the color conversion is performed and printed according to the color conversion setting) is instructed (S104).

When the printer 20 to be output receives the image data of the color verification chart, the control unit 21 (ICC profile setting unit 21a sets the ICC profile according to the color conversion setting instructed by the color verification system 40, and the control unit 21 (ICC profile setting unit 21a) The CMM21b) applies the set ICC profile to perform color conversion, and the print processing unit 29 prints the color verification chart based on the image data after the color conversion.

On the other hand, if the output target printer 20 is a printer for which color conversion setting cannot be performed (No in S102), the control unit 41 (CMM difference acquisition unit 41g) acquires an error due to the CMM difference (color conversion error). , It is determined whether the error is equal to or more than a predetermined value (S105). Specifically, when the same profile is applied and color conversion is performed using the CMM 41c of the own device and when color conversion is performed using the CMM 21b of the printer 20, the device value or image data of the image data The error generated in the color measurement value obtained by measuring the color of the color verification chart printed based on the above is acquired, and it is determined whether the acquired error is equal to or more than a predetermined value.

When the error due to the difference in CMM is equal to or greater than a predetermined value (for example, average ΔE> 0.5 or maximum ΔE> 2.0) (Yes in S105), the ICC profile setting unit 41b sets and controls the ICC profile. After the unit 41 (color conversion unit 41d of CMM 41c) applies the set ICC profile to perform color conversion (S106), the control unit 41 (CMM difference correction unit 41e of CMM 41c) stores the correction LUT stored in advance. With reference to this, the image data of the color verification chart is corrected by applying a correction amount corresponding to the error due to the difference in CMM (S107), and the color-converted and corrected image data is created (S108). Then, the control unit 41 (output instruction unit 41a) transmits the image data of the color conversion and corrected color verification chart to the printer 20 and turns off the color conversion (operation mode for printing without performing the color conversion). Instruct the output (S109).

When the printer 20 to be output receives the image data of the color verification chart that has been color-converted and corrected, the control unit 21 (CMM21b) does not perform color conversion, and the print processing unit 29 is based on the received image data. Print the color verification chart.

On the other hand, if the error due to the difference in CMM is less than a predetermined value (No in S105), there is no problem even if the error due to the difference in CMM is not corrected. Therefore, the ICC profile setting unit 41b sets and controls the ICC profile. The unit 41 (color conversion unit 41d of the CMM 41c) applies the set ICC profile to perform color conversion (S110), and creates color-converted image data (S111). Then, the control unit 41 (output instruction unit 41a) transmits the image data of the color verification chart that has been color-converted to the printer 20 and outputs the output in the color conversion OFF (printing operation mode without color conversion). Instruct (S112).

When the output target printer 20 receives the image data of the color verification chart that has been color-converted, the control unit 21 (CMM21b) does not perform color conversion, and the print processing unit 29 performs color verification based on the received image data. Print the chart.

After that, the colorimeter 60 acquires the color measurement value measured by the colorimeter 60 from the color verification chart output from the printer 20 (S113), and the control unit 41 (color verification unit 41h) sets the target of the obtained color measurement value. Color verification is performed by measuring the color difference with respect to the color measurement value, and the result of the color verification is output to the client device 50 or the like (S114). When the client device 50 receives the result of the color verification, the client device 50 displays the result of the color verification on the display unit and notifies the user. As an item for displaying the result of color verification, an item (the color space and index) defined by an organization such as "Japan Color", "Fogra", and "IDE Alliance" may be used, and the user can use any item. It may be possible to set a target color and verification items.

As described above, the color verification system 40 has a correction amount for correcting an interpolation error or an error due to a setting not defined by an ICC profile between its own CMM 41c and the CMM 21b of the printer 20. When a correction LUT that describes (CMYK value or L * a * b * value) is created and the printer 20 outputs a color verification chart, the output target printer 20 is set to color conversion from the color verification system 40. It is determined whether the printer can be used, and in the case of a printer whose color conversion setting cannot be set from the color verification system 40, it is determined whether the error due to the difference in CMM is equal to or greater than the predetermined value, and the error due to the difference in CMM is equal to or greater than the predetermined value. In this case, after performing color conversion by applying the ICC profile, correction is performed to eliminate the error due to the difference in CMM by referring to the correction LUT, and the corrected image is output to the printer 20 with color conversion OFF. Similar color conversion results can be obtained at the time of output and at the time of color verification.

The present invention is not limited to the above embodiment, and the configuration and control of the printing system and each device can be appropriately changed as long as the gist of the present invention is not deviated.

For example, in the above embodiment, the L * a * b * value in the CIE 1976 color space is illustrated as the color measurement value, but it may be the XYZ value in the CIE 1931 color space.

The printer 20 may be a CMYK printer, an RGB printer, an electrophotographic printer, an inkjet printer, an offset printing machine, or the like.

The present invention can be used for a color conversion control program for controlling color conversion for outputting a color verification chart, a recording medium on which the color conversion control program is recorded, and a color conversion control method.

10 Printing system 20 Printer 21 Control unit 21a ICC profile setting unit 21b CMM
22 CPU
23 ROM
24 RAM
25 Storage unit 26 Network I / F unit 27 Display operation unit 28 Image processing unit 29 Print processing unit 30 Controller 40 Color verification system 41 Control unit 41a Output instruction unit 41b ICC profile setting unit 41c CMM
41d Color conversion unit 41e CMM difference correction unit 41f Printer type determination unit 41g CMM difference acquisition unit 41h Color verification unit 42 CPU
43 ROM
44 RAM
45 Storage unit 46 Network I / F unit 50 Client device 60 Colorimeter 70 Communication network

Claims (11)

A color conversion control program that operates in a device that performs color verification by outputting a color verification chart to a printer that has a CMM (Color Management Module) that performs color conversion.
In the device
The first process of acquiring the information of the output target printer of the color verification chart and specifying the CMM of the output target printer,
The second process of acquiring an error in color conversion due to the difference in CMM when the CMM of the own device and the CMM of the printer to be output are different.
Third process to set the ICC (International Color Consortium) profile,
A fourth process of applying the set ICC profile and performing color conversion on the image data of the color verification chart using the CMM of the own device.
Fifth process of correcting the error of the color conversion with respect to the image data of the color verification chart that has undergone the color conversion with reference to the correction LUT stored in advance.
A sixth process of transmitting the image data of the color verification chart that has undergone the color conversion and the correction to the printer to be output is executed.
A color conversion control program characterized by this. In the first process, based on the acquired information, it is determined whether the output target printer is a printer capable of specifying the ICC profile output.
In the fifth process, when the printer to be output is a printer that cannot output the specified output of the ICC profile, the error of the color conversion is corrected.
The color conversion control program according to claim 1. In the second process, it is determined whether or not the color conversion error is equal to or greater than a predetermined value.
In the fifth process, when the color conversion error is equal to or greater than the predetermined value, the color conversion error is corrected.
The color conversion control program according to claim 1 or 2. Before causing the apparatus to perform the first to sixth processes,
A process of applying the same ICC profile in advance, generating a plurality of color-converted image data using different CMMs, and using the difference between the device values of the plurality of image data to create the correction LUT is executed.
The color conversion control program according to any one of claims 1 to 3, wherein the color conversion control program is characterized. Before causing the apparatus to perform the first to sixth processes,
Obtained by applying the same ICC profile in advance, generating a plurality of color-converted image data using different CMMs, creating a plurality of printed matter based on the plurality of image data, and measuring the color of the plurality of printed matter. The process of creating the correction LUT is executed using the difference between the measured color values.
The color conversion control program according to any one of claims 1 to 3, wherein the color conversion control program is characterized. A color conversion control method in a printing system including a printer having a CMM (Color Management Module) that performs color conversion and a device that prints a color verification chart on the printer to perform color verification.
The device
The first process of acquiring the information of the output target printer of the color verification chart and specifying the CMM of the output target printer, and
When the CMM of the own device and the CMM of the printer to be output are different, the second process of acquiring the error of color conversion due to the difference of the CMM, and
The third process of setting the ICC (International Color Consortium) profile and
The fourth process of applying the set ICC profile and performing color conversion on the image data of the color verification chart using the CMM of the own device, and
With reference to the correction LUT stored in advance, the fifth process of correcting the error of the color conversion with respect to the image data of the color verification chart that has undergone the color conversion, and
The sixth process of transmitting the image data of the color verification chart that has undergone the color conversion and the correction to the printer to be output is executed.
The output target printer is
After receiving the image data of the color verification chart, the color verification chart is printed based on the received image data without performing color conversion.
A color conversion control method characterized by that. In the first process, based on the acquired information, it is determined whether the output target printer is a printer capable of specifying the ICC profile output.
In the fifth process, when the printer to be output is a printer that cannot output the specified output of the ICC profile, the error of the color conversion is corrected.
The color conversion control method according to claim 6, wherein the color conversion control method is characterized. In the second process, it is determined whether or not the color conversion error is equal to or greater than a predetermined value.
In the fifth process, when the color conversion error is equal to or greater than the predetermined value, the color conversion error is corrected.
The color conversion control method according to claim 6 or 7. The apparatus may perform the first to sixth processes before performing the first to sixth processes.
The same ICC profile is applied in advance, a plurality of color-converted image data are generated using different CMMs, and the correction LUT is created by using the difference between the device values of the plurality of image data.
The color conversion control method according to any one of claims 6 to 8, wherein the color conversion control method is characterized. The apparatus may perform the first to sixth processes before performing the first to sixth processes.
Obtained by applying the same ICC profile in advance, generating a plurality of color-converted image data using different CMMs, creating a plurality of printed matter based on the plurality of image data, and measuring the color of the plurality of printed matter. The correction LUT is created by using the difference between the measured color values.
The color conversion control method according to any one of claims 6 to 8, wherein the color conversion control method is characterized. The device further
The color measurement value of the color verification chart printed by the output target printer is acquired, and color verification is performed based on the acquired color measurement value.
The color conversion control method according to any one of claims 6 to 10, wherein the color conversion control method is characterized.

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