JP2006261731A - Color shift compensation device, colorimetry device, print controller, color correction data preparation device, color shift compensation method, and color shift compensation program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve color reproducibility to a reference color by eliminating deviations in colorimetry results of patches due to difference between back materials for colorimetry (mat materials for colorimetry). <P>SOLUTION: Colorimetry results of a compensation target, which are obtained by measuring colors of the patches on a print medium under a colorimetry environment different from a reference colorimetry environment made as a reference of the environment for measuring the colors of the patches on the print medium, are acquired. The shift of the colorimetry results (color data) due to the difference between the colorimetry environment and the reference colorimetry environment is compensated from comparison results obtained after comparing the reference colorimetry results, which are obtained by measuring the colors of the patches on the print medium under the reference colorimetry environment, with the colorimetry results of the compensation target. The back material for colorimetry is included in the environment subjected to the colorimetry. The shift of the colorimetry results due to the difference between the print medium, on which an image for acquiring the colorimetry results of the compensation target is formed, and the print medium, on which the patches used for obtaining the reference colorimetry results are formed, may be compensated together with the shift of the colorimetry results due to the difference between the colorimetry environments. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color misregistration compensation device, a color measurement device, a print control device, a color correction data creation device, a color misregistration compensation method, and a color misregistration compensation program.

  Conventionally, a print control apparatus refers to a color conversion LUT (color conversion table) and converts image data composed of gradation values for RGB (red, green, blue) for each CMYK (cyan, magenta, yellow, black), for example. Convert the color to image data consisting of gradation values, determine the dot recording rate for each dot size that can be formed by a color printer, and whether or not to form dots for each dot size based on the determined dot recording rate Based on the determination result, each dot is formed on the printing paper (printing medium) by the printer. In order to reproduce the gradation of each color as accurately as possible, an effort has been made to make the weight of ink ejected per unit area as accurate as possible.

In the technology described in Patent Document 1, a color colorimeter is provided in a printer, and correction information based only on the ground color of the medium is created in order to correct the ground color of the medium (printing medium). After the CMYK data representing the used amount is corrected by subtraction of the correction information, it is converted into data representing the dot formation amount for each CMYK, and printing control for the printer is performed. Specifically, the background color of the media is measured with the same color meter to acquire the background color measurement data, and the background color measurement data is obtained for each CMYK by referring to the media profile for the reference media. The input image data is converted to first output image data composed of tone values, and the input image data in which the gradation values for each CMYK are all 0 with reference to the print profile and the media profile for the reference medium is second image data. The correction value is information including gradation values for each CMYK obtained by subtracting the gradation values of the first image data from the gradation values of the second image data. Then, image data composed of gradation values for each CMYK is converted into CMYK data representing the amount of ink used for each CMYK based on the profile information, and correction is performed by subtracting the same correction value from each gradation data.
JP 2003-271327 A

  When the printer is calibrated, a color chart composed of a plurality of patches (color charts) is printed on the print medium by the printer, and the print medium is placed on a sheet-like measurement backing material (color measurement flooring material). The colorimetry is carried out by placing a colorimeter detector on each patch. Some back materials for measurement have a black surface and others have a white surface, and an error has occurred in the color measurement result due to the brightness of the back material. Therefore, it has been desired to improve the color reproducibility with respect to the reference color by eliminating the shift in the color measurement result of the patch due to the difference in the back material.

  The present invention has been made in view of the above problems, and an object thereof is to improve color reproducibility with respect to a reference color.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, the color misregistration compensator of the present invention measures color data of an image formed on a print medium and generates color data representing a color corresponding to the image on the print medium. A color misregistration compensation device that compensates for color misregistration in a generation device, and measures an image on the print medium in a colorimetric environment different from a reference colorimetric environment that is a standard of the environment for colorimetric measurement of the image on the print medium. Color measurement result acquisition means for acquiring a color measurement result of a color to be compensated; a color measurement result of a reference obtained by color measuring an image on the print medium in the standard color measurement environment; and a color measurement of the compensation target And a color correction means for comparing the result and compensating for a shift in the color data due to a difference in the colorimetric environment with respect to the reference colorimetric environment based on the comparison result.

The color measurement result acquisition unit acquires a color measurement result to be compensated by measuring the image on the print medium in a color measurement environment different from the reference color measurement environment. The reference color measurement environment is a reference for an environment for measuring the color of an image on a print medium. Then, the color correction means compares the reference color measurement result with the color measurement result to be compensated, and compensates the deviation of the color data due to the difference in the color measurement environment with respect to the reference color measurement environment from the comparison result. . The reference color measurement result is a reference color measurement result obtained by measuring an image on a print medium in a reference color measurement environment.
As described above, the color data is data in which the color shift generated in the color represented by the color data due to the difference in the color measurement environment with respect to the reference color measurement environment is compensated. As a result, the color represented by the color data is a color in which the color shift due to the difference in the colorimetric environment is compensated. Therefore, it is possible to compensate for the color shift due to the difference in the environment for measuring the color of the image on the print medium, and it is possible to improve the color reproducibility of the color represented by the color data with respect to the reference color.

Here, the color data includes colorimetric values, print data representing a print image, calibration data such as a one-dimensional LUT for calibration, color conversion data such as a color conversion LUT, and dot distribution such as a dot distribution table. Minute data, and so on.
The color data generation device includes a colorimeter, a print control device that controls the printing device, a device that creates calibration data, a device that creates color conversion data, a device that creates dot distribution data, and the like. be able to.
The colorimetric results are the values of the color components L ^* , a ^* , b ^* of the CIE L ^* a ^* b ^* color space defined by the International Commission on Illumination (CIE), the CIE L ^* u ^* v ^* color space. Color components L ^* , u ^* , v ^* , CIE XYZ color space color components X, Y, Z values, RGB color space color components R, G, B values, these color components Secondary values obtained from the respective values, etc. Note that L ^* is an element color representing lightness (brightness), and a ^* , b ^* , u ^* , and v ^* are element colors representing hue and saturation. Hereinafter, “ ^* ” is omitted.
Acquiring the color measurement result obtained by measuring the image by the color measurement result acquisition unit may or may not include color measurement of the image.

In the case where the color data generating device is a device that generates the color data by measuring the image on the printing medium arranged on the surface of the color measuring flooring material, the color correcting means includes a reference color measuring floor. The shift of the color data due to the difference in the colorimetric flooring material with respect to the material may be compensated. The color represented by the color data is compensated for color misregistration due to the difference in the color measuring flooring material. Therefore, it is possible to improve the color reproducibility of the color represented by the color data.
It is particularly preferable that the color data generation apparatuses are of the same model because color misregistration due to a difference in colorimetric flooring material is more accurately compensated.

The color correction means may compensate for a shift in the color data due to a difference in brightness of the colorimetric flooring surface relative to the brightness of the reference colorimetric flooring surface from the comparison result. The color represented by the color data is compensated for color misregistration due to the difference in brightness of the colorimetric flooring surface. Therefore, the color reproducibility of the color represented by the color data is improved.
The brightness can be brightness, brightness, a combination of XYZ in the XYZ color system, darkness, and the like.

  The color correction means, for the color represented by the color data, the compensation amount of the brightness component in the relatively bright first brightness range from the compensation amount of the brightness component in the relatively dark second brightness range. The color data may be corrected so as to increase the value. Then, the deviation of the brightness component generated in the color represented by the color data due to the difference in the colorimetric flooring is appropriately compensated.

  The color correction means obtains a difference in brightness component between the reference color measurement result and the compensation color measurement result, and based on the obtained difference in brightness component, the color saturation represented by the color data is calculated. The color data may be modified to compensate for the deviation of the degree component. The color shift of the saturation component is compensated based only on the difference of the normal saturation component. In the present invention, since the color shift of the saturation component is compensated based also on the difference of the brightness component, the shift of the saturation component generated in the color represented by the color data due to the difference in the colorimetric flooring is appropriate. Will be compensated for.

  The color correction means, for the color represented by the color data, the saturation component compensation amount in the relatively bright first brightness range from the saturation component compensation amount in the relatively dark second brightness range. The color data may be corrected so as to increase the value. Then, the shift of the saturation component that occurs in the color represented by the color data due to the difference in the color measurement flooring material is appropriately compensated.

  The color correction means is configured to determine a saturation component compensation amount in a first saturation range having a relatively high saturation for the color represented by the color data, in a second saturation range having a relatively low saturation. The color data may be corrected so as to be larger than the compensation amount of the degree component. Then, the shift of the saturation component that occurs in the color represented by the color data due to the difference in the color measurement flooring material is appropriately compensated.

  The color correction means may compensate for the color data shift due to a difference in colorimetric environment and the color data shift due to a print medium difference. The color represented by the color data is compensated for the color shift generated in the color represented by the color data due to the difference in the colorimetric environment, and the color shift generated in the color represented by the color data due to the difference in the print medium. Is compensated. Therefore, the color shift represented by the color data is more appropriately compensated. Further, if the amount of light transmitted through the print medium varies, the color represented by the color data is shifted even if the ground color of the print medium is the same. However, the color correction unit compensates for such color shift.

  When the color correction unit compensates for the shift of the color data due to the difference in the print medium, the color component of the saturation component in the first saturation range where the saturation is relatively large for the color represented by the color data. The color data may be modified so that the compensation amount is smaller than the saturation component compensation amount in the second saturation range where the saturation is relatively small. Then, the color shift represented by the color data is more appropriately compensated.

  When the color correction unit compensates for the shift of the color data due to the difference in the print medium, the color correction unit calculates the compensation amount of the saturation component in the relatively bright first brightness range for the color represented by the color data. The color data may be corrected so as to be larger than the compensation amount of the saturation component in the relatively dark second brightness range. Then, the color shift represented by the color data is more appropriately compensated.

  The color correction means corrects the color data only when the color represented by the color data is less than or less than a predetermined saturation when compensating for the shift of the color data due to a difference in print media. Also good. When the color represented by the color data is greater than or equal to a predetermined saturation, the print image is formed at a high density on the print medium, and is not easily affected by the difference in the print medium. Therefore, the processing for compensating for the color shift represented by the color data is accelerated.

By the way, a color measurement device that measures the color of an image formed on a print medium and generates a color measurement result, a print control device that controls a print device that forms a print image corresponding to print data on the print medium, Even in the color correction data creating apparatus that creates color correction data that defines the correspondence before and after the correction of the print data in order to compensate for color misregistration in the printing apparatus that forms the print image corresponding to the print data on the print medium, The same operations and effects as those obtained by the color misregistration compensation apparatus can be obtained.
The color correction data can be calibration data, color conversion data, dot distribution data, and the like.

The color misregistration compensation device, the color measurement device, the print control device, and the color correction data creation device described above include various modes such as being implemented together with other methods in a state of being incorporated in a certain device. For example, the present invention can be applied as a printing system including a printing unit. In addition, since it is possible to proceed with processing according to a predetermined procedure corresponding to the configuration of these devices, the present invention is also applicable as a control method, and the invention according to claim 15 has the same operation, There is an effect. Furthermore, since the control program may be executed by these devices, the present invention can also be applied as the control program or a computer-readable recording medium on which the program is recorded. Produces the same actions and effects.
Of course, the configurations described in claims 2 to 13 can be applied to the above method, system, program and recording medium.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of a printing system having a color misregistration compensation device:
(2) Calibration data creation process:
(3) Modification:

(1) Configuration of a printing system having a color misregistration compensation device:
FIG. 1 is a diagram schematically illustrating a configuration of a color misregistration compensation apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram illustrating a schematic configuration of a printing system 100 including the color misregistration compensation apparatus. The printing system 100 includes a reference printing system 100a that obtains a reference colorimetric result by measuring an image on a print medium in a reference colorimetry environment that is a reference of an environment for measuring an image on the print medium. And a compensation printing system 100b that compensates for color misregistration by measuring an image on a print medium in a color measurement environment different from the color environment. Here, the printing system 100b includes a personal computer (PC) 10, an ink jet printer 20 connected to the PC, a color colorimeter 40, and the like. The printing system 100b includes a PC 60, an ink jet printer 70 connected to the PC, a color colorimeter 90, and the like. The PCs 10 and 60 are connected to each other by communication I / Fs 17d and 67d via a communication line 98 such as a LAN or the Internet network. Of course, the computer used in the present invention is not limited to a PC.

FIG. 3 shows the configuration of the printing system 100b. Although not shown, the reference printing system has the same configuration.
In the PC 10, the CPU 11 controls the entire PC via the system bus 10a. Connected to the bus 10a are a ROM 12, a RAM 13 which is a semiconductor memory capable of rewriting data, a CD-ROM drive 15, a flexible disk (FD) drive 16, various interfaces (I / F) 17a to 17e, etc. A hard disk (HD) 14 that is a magnetic disk is also connected via the. The HD 14 stores the color misregistration compensation program 14a of the present invention, which is transferred to the RAM 13 by the CPU 11 and executed at the time of execution. The HD 14 is a predetermined storage area (data recording area) that stores (records) the reference color measurement result 14b, the compensation color measurement result 14c, and the like. The RAM 13 temporarily stores a reference color measurement result 13a, a color measurement result 13b to be compensated, a color measurement result 13c after compensation, and the like.

A known color measuring device 40 is connected to the I / F 17a (for example, USB I / F). The color measuring device 40 and the color measuring device 90 are also called colorimeters, and a plurality of color components based on the Lab color system in the CIE (1976) standard by directing the color detection units 40a and 90a to the object to be measured. It is possible to detect color component amounts of L, a, and b and generate colorimetric values (colorimetric results) L, a, and b corresponding to the detected amounts. The colorimeters 40 and 90 can output the generated colorimetric values L, a, and b to the PCs 10 and 60. Here, the CIE Lab color space (predetermined color space) is a uniform color space that does not depend on a device having a plurality of color components L, a, and b as color component amounts. Note that L represents lightness (brightness), and a and b are color coordinates representing hue and saturation. Of course, the color space for color measurement may be a CIE XYZ color space, a CIE Luv color space, an RGB color space, or the like.
When the printer 20 is calibrated, the print medium M2 on which the color chart is printed is placed on a sheet-like colorimetric back material (colorimetric flooring material) B2, and the colorimeter is placed on each patch P2. The color measurement is performed by applying the detection unit 40a of 40, and the colorimeter 40 is caused to generate a colorimetric value. In the colorimeter 90, the print medium M1 on which the color chart is printed is placed on a sheet-like reference colorimetric back material (reference colorimetric flooring material) B1, and colorimetry is performed on each patch P1. The color is measured by applying the detection unit 90a of the machine 90. The backing material used as the underlay of the printing medium has an achromatic color with various brightness (brightness) such as black, white, and gray on the surface.
It is preferable that the colorimeter 40 and the colorimeter 90 are the same model because a shift in the color measurement result due to a difference in the color measurement flooring material can be more accurately compensated.
A display 18a for displaying an image corresponding to the data based on color image data is connected to the CRTI / F 17b. A keyboard 18b and a mouse 18c are connected to the input I / F 17c as operation input devices, and a printer I / F 17e. For example, the printer 20 is connected via a serial I / F cable.

The printer 20 serving as a printing apparatus (printing unit) includes six inks filled in six ink cartridges 28 respectively corresponding to CMYRVK (cyan, magenta, yellow, red, violet, and black) colors. (Recording material) is ejected from the print head, and ink is attached to a print medium such as print paper to form dots, thereby forming a print image corresponding to print data representing a color image. Of course, the printer 20 includes a printer that uses light cyan, light magenta, light black, dark yellow, non-colored ink, etc., a printer that does not use any of CMYRVK ink, and generates ink in the ink passage by generating bubbles. A bubble type printer that discharges, a laser printer that forms a printed image on a print medium using toner ink, and the like can also be employed. The ink used by the printing device may be liquid or solid. Each ink of the present embodiment is an ink in which a coloring material composed of a fine pigment is mixed in an aqueous solvent, but may be an ink in which a coloring material composed of a dye is mixed, or an ink using an oil-based solvent.
In the printer 20, a CPU 21, a ROM 22, a RAM 23, a communication I / O 24, a control IC 25, an ASIC 26, an I / F 27, and the like are connected via a bus 20 a, and the CPU 21 controls each unit according to a program written in the ROM 22.

A carriage that reciprocates in the main scanning direction by the carriage mechanism 27a is provided with a cartridge holder 32 on which each ink cartridge 28 can be mounted at a predetermined mounting location, and a print head unit 29 is mounted. . In the holder 32 of the present embodiment, six mounting locations corresponding to each of all six types of ink are formed. Each cartridge 28 is formed with a predetermined filling chamber capable of being filled with ink of a corresponding color, and is detachably attached to each attachment portion of the holder 32.
The print head unit 29 includes print heads 29a to 29f provided for each of six types of CMYRVK inks and a semiconductor memory 31 such as an EEPROM. Each of the print heads 29a to 29f installed in the printer can eject ink of a corresponding color and adhere to the print paper, and the printer 20 uses the corresponding print head 29a to f for each type of ink. Then, dots are formed on the print medium to print the image.
Each cartridge 28 is also provided with a semiconductor memory 28a such as an EEPROM, for example, and each memory 28a is electrically connected to the control IC 25.

  The communication I / O 24 is connected to the printer I / F 17e of the PC. The printer 20 can receive color-specific raster data transmitted from the PC 10 via the communication I / O 24 and output various types of information to the PC 10. The ASIC 26 outputs applied voltage data corresponding to the raster data to the head driving unit 26a while transmitting / receiving a predetermined signal to / from the CPU 21. The head drive unit 26a generates an applied voltage pattern to the piezo elements incorporated in the print heads 29a to 29f from the applied voltage data, and causes the print heads 29a to 29f to eject six colors of ink in dot units. The carriage mechanism 27a and the paper feed mechanism 27b connected to the I / F 27 cause the print head unit 29 to perform main scanning, and sequentially feed print sheets while performing a page break operation as appropriate, thereby performing sub-scanning.

A plurality of inkjet nozzles are provided for each color in the print heads 29a to 29f, and piezoelectric elements are arranged corresponding to the respective nozzles. As described in Japanese Patent Laid-Open No. 2003-182120 (particularly, paragraphs 0024-0025) and Japanese Patent Laid-Open No. 2003-291327, the larger the voltage difference in the drive waveform of the voltage applied to the piezo element, the larger the dot. Become. The printer 20 can form a plurality of dots (large, medium, and small dots) having different ink weights on a print medium, and ejects ink of different levels of ink from the same print head for each color. A dot having a size corresponding to the ink amount is formed. The raster data transmitted from the PC to the printer is added with identification information for identifying the type of dot, and the printer forms a type of dot corresponding to the identification information. When raster data composed of dot data representing the type of dot is input for each raster, the printer forms a plurality of types of dots having different ink amounts on the print medium in accordance with the raster data.
Examples of the print medium include a coated paper print medium including glossy paper and the like, and a non-coated paper print medium including plain paper and recycled paper. Since the coated paper is easier to improve the color accuracy than the non-coated paper, it is particularly preferable to apply the present invention.

  The color misregistration compensation program may be configured by any of an operating system (OS), an application program (APL), and OS and APL. In addition to the HD 14, the medium storing the program may be a CD-ROM, FD 16a, semiconductor memory, or the like. Further, the communication I / F 17d may be connected to the Internet network, and the program of the present invention may be downloaded from a predetermined server and executed.

  As shown in FIG. 1, the color misregistration compensation apparatus includes the units U1 and U2 provided in the printing system 100b. A color shift in a color data generation device that generates color data representing a corresponding color is compensated. In this embodiment, the color data generation device is a color measurement device, and the color data is a color measurement result. The color measuring device includes a PC 10 and a color measuring device 40. Note that the color misregistration compensation apparatus may further include a reference color measurement result acquisition unit U11 provided in the printing system 100a.

The reference color measurement result acquisition unit (reference color measurement result acquisition unit) U11 prints a color chart including a plurality of patches (images) P1 with a recording material on the print medium M1 as necessary, and displays an image on the print medium. The color of the patch P1 on the print medium M1 is measured in the reference color measurement environment that is the reference of the environment for color measurement, and the reference color measurement result DA1 is acquired.
The color measurement result acquisition unit (color measurement result acquisition means) U1 prints a color chart composed of a plurality of patches (images) P2 with a recording material on the print medium M2 as necessary, and performs a measurement different from the reference color measurement environment. The color of the patch P2 on the print medium M2 is measured in the color environment, and the color measurement result DA2 to be compensated is acquired.
The color correction unit (color correction means) U2 compares the reference color measurement result DA1 and the color measurement result DA2 to be compensated, and the color measurement result (color) based on the difference between the comparison result and the reference color measurement environment. Compensation for data deviation.

  The colorimeter 40 measures the color of the patch P2 on the print medium M2 disposed on the surface B2a of the colorimetric back material (colorimetric flooring material) B2, and generates a colorimetric result DA2. Since the surface of the color measurement back material has various brightness, the brightness of the surface B1a of the color measurement back material B1 used when generating the reference color measurement result DA1 and the color measurement result DA2 to be compensated are obtained. The brightness of the surface B2a of the colorimetric back material B2 used for generation may be different.

  FIG. 4 shows a result of measuring each patch color by arranging a printing medium on which patches of recording density of a plurality of stages are printed with Y pigment ink on the surface of a different colorimetric back material. As shown in the figure, the color measurement result of each patch placed on the black surface backing material (upper side of the figure) is the color measurement result of each patch placed on the white surface backing material (lower side of the figure) ), L (lightness) is small, b (saturation) is small, and as b increases, b tends to become smaller (b difference becomes larger).

FIG. 5 shows the relationship between the lightness L and the lightness difference ΔL of each patch placed on the black surface back material, and the black surface back, with respect to the colorimetric value shift due to the lightness difference on the color measurement back material surface. Relationship between saturation C = (a ² + b ² ) ^{1/2 of} each patch placed on the material and saturation difference ΔC, lightness L and saturation of each patch placed on the black surface backing material The relationship with the difference ΔC is shown. Here, if the colorimetric result of the patch placed on the black surface backing material is L1, a1, b1, and the colorimetric result of the patch placed on the white surface backing material is L2, a2, b2, ΔL = L2−L1, ΔC = (a2 ² + b2 ² ) ^1/2 − (a1 ² + b1 ² ) ^1/2 The difference in lightness component means the absolute value of ΔL (| ΔL |), and the difference in saturation component means the absolute value of ΔC (| ΔC |).
Hereinafter, the shift of the color measurement result due to the difference in the backing material will be described.

In the chromatic color ink, the lightness L is smaller and the saturation C is smaller on the black surface, and as shown in the L-ΔL graph in the figure, the lightness difference ΔL tends to increase as the lightness L increases. In the achromatic color ink, L is smaller on the black surface, and as shown in the L-ΔL graph of the figure, there is a tendency that as L increases, ΔL increases. The print medium is a thin sheet, and the black color can be seen through the print medium placed on a black surface. For this reason, the lightness of the patch is considered to be smaller on the black surface. Further, in the print medium, the black color is more transparent as the patch brightness increases. Therefore, it is considered that the brightness difference between patches increases as the patch brightness increases.
In the chromatic color ink, as shown in the C-ΔC graph in the figure, the saturation difference ΔC tends to increase as the saturation C increases. In print media placed on a black surface, it is considered that the saturation of the patch decreases as the black color passes through, and the saturation between the patches increases as the saturation of the patch increases due to the influence of the black color. The degree difference is considered to be large.
In the chromatic color ink, as shown in the L-ΔC graph in the figure, the “saturation difference ΔC” tends to increase as the “lightness L” increases. In a print medium placed on a black surface, it is considered that the saturation of the patch is reduced due to the black transparency, and it is considered that the saturation difference between patches increases as the brightness of the patch increases due to the influence of the black.

  Therefore, by measuring the ground color of the print medium and subtracting the color measurement result from the color data to be calibrated, the color measurement back material surface color differs from the color of the reference color measurement back material surface. Color misregistration cannot be compensated. In the present embodiment, in consideration of the difference in the colorimetric environment of the colorimetric back material, the color data shift is appropriately compensated to improve the reproducibility of the color represented by the color data.

  That is, the reference color measurement result acquisition unit U11 is on the print medium M1 arranged on the surface B1a of the reference color measurement back material B1 used as a reference of the color measurement back material used for color measurement of the patch on the print medium. The color of the patch P1 is measured to obtain a reference color measurement result DA1. Further, the color measurement result acquisition unit U1 measures the color of the patch P2 on the print medium M2 arranged on the surface B2a of the color measurement back material B2 different from the reference color measurement back material B1, and performs the color measurement to be compensated. Obtain the result DA2. Here, it is assumed that the surfaces B1a and B2a of the backing materials B1 and B2 have achromatic colors with different brightness. The color correcting unit U2 compares the colorimetric results DA1 and DA2, and based on the comparison result, the difference in lightness (brightness) of the colorimetric back material surface B2a with respect to the lightness (brightness) of the reference colorimetric back material surface B1a. Compensates for shifts in color data due to.

  FIG. 6 shows the relationship between the saturation C and the saturation difference ΔC of each patch placed on the black surface backing material and the color measurement value shift due to the difference in the printing medium, placed on the black surface backing material. The relationship between the lightness L of each patch and the saturation difference ΔC is shown. Note that the following description is about misalignment of color measurement results due to differences in print media.

In the chromatic ink, as shown in the C-ΔC graph in the figure, the saturation difference ΔC decreases as the saturation C increases, and the saturation difference tends to become zero at a certain saturation Cm or higher. This is presumably because if the saturation of the patch is small, it is easily affected by the background color of the print medium, but if the saturation of the patch is large, it is difficult to be influenced by the background color of the print medium. Also, the reason why the saturation difference disappears at a certain saturation Cm or more is considered to be because the recording material covers the print medium.
In the chromatic color ink, as shown in the L-ΔC graph in the figure, the “saturation difference ΔC” tends to increase as the “lightness L” increases. This is considered to be because if the lightness of the patch is small, it is difficult to be influenced by the ground color of the print medium, but if the lightness of the patch is large, it is easily affected by the ground color of the printing medium.

  Therefore, the color correction unit U2 compares the colorimetric results DA1 and DA2, and the image obtained from the comparison result is a color data shift due to a difference in the colorimetric environment with respect to the reference colorimetric environment, and an image obtained as a reference colorimetric result The color data shift due to the difference in the print medium M1 on which the patch for obtaining the color measurement result to be compensated for the formed print medium M1 is compensated is compensated. Thereby, the color shift represented by the color data is more appropriately compensated.

FIG. 7 is a diagram schematically showing the data structure of calibration data (color correction data) DA4 created using the colorimetry results with the offset compensated, and FIG. 8 is a diagram illustrating calibration using the data DA4. 6 is a flowchart illustrating a print control process for performing print control while performing the print control. FIG. 9 is a diagram schematically illustrating the print control process. This print control process is performed by the PC 10. Note that the processing of steps S105 to S115 and S125 to S140 can also be executed by the PC 60. Hereinafter, the description of “step” is omitted.
When the print control process is started, the type of printer that performs printing and various printing conditions are acquired (S105). When the type of printer is specified, the type of recording material used for printing is also specified. Printing conditions include the type of print medium, paper size, resolution, and the like.

  First, the PC 10 receives image data composed of gradation data corresponding to a plurality of element colors for each pixel, and RGB data D1 in a wide-range RGB color space in which an image is represented by a plurality of pixels for each RGB. (S110). Inputting image data includes partially reading data, passing a pointer representing a buffer area used for data transfer, and the like. The input image data is data in which an image is expressed in gradation by a large number (predetermined number) of pixels in the form of a dot matrix. The image data is composed of RGB defined in the sRGB color space, or in the YUV color system. Image data composed of YUV, and the like. Since each component of the image data has various gradation numbers, the image data is converted into RGB data D1 of 256 gradations of RGB in a wide RGB color space in accordance with definitions such as sRGB and YUV color system. The RGB data is image data (a type of print data) in which an image is expressed by gradation data for each element color RGB for each pixel.

Next, the RGB data D2 is used by the printer by referring to the color conversion LUT (color conversion table) while sequentially moving the target pixel using the gradation data of each pixel constituting the RGB data D1 as the conversion target. Color conversion is performed to CMYRVK data D2 expressed by gradation data for each CMYRVK corresponding to the ink color (S115). The color conversion LUT is an information table that defines the correspondence between the gradation data for each RGB and the gradation data in which the amount of ink used in the printer is represented for each CMYRVK for a plurality of reference points. If the data that matches the input gradation data for each RGB is not stored in the color conversion LUT, the gradation data for each CMYRVK corresponding to the gradation data for each RGB that is close to the gradation data for each RGB is obtained. A plurality of sets are acquired and converted into gradation data for each CMYRVK corresponding to the gradation data for each RGB input by interpolation such as volume interpolation. Like the RGB data, the CMYRVK data D2 is image data (a kind of print data) in which an image is expressed in gradation for each element color CMYRVK with a large number (predetermined number) of pixels in a dot matrix. It is assumed that the data is CMYRVK 256 gradation data representing the amount of ink used by the printer 20 ejected from the print head.
Even if the printer performs printing using the CMYRVK data at this stage, there may be a slight error in the color of the image printed on the print medium. This is due to a deviation in the weight of ink ejected from each print nozzle row. Therefore, CMYRVK data is corrected so as to compensate for such color variations.

Thereafter, the CMYRVK data D3 is corrected by correcting the CMYRVK data D2 by referring to the calibration data DA4 while sequentially moving the target pixel with the gradation data of each pixel constituting the CMYRVK data D2 as the correction target. Is generated (S120). As shown in FIG. 7, the calibration data DA4 can be a one-dimensional information table showing the correspondence before and after the correction of CMYRVK data for compensating for color misregistration. For example, the calibration data DA4 indicates, for each color, the correspondence between the input gradation value Ai (i is an integer from 0 to 255) and the output gradation value, and each gradation (all gradations) of the input gradation value Ai. The information table is defined as When the gradation value of the CMYRVK data before correction is Ai, in the example of the figure, the output gradation value ACi corresponding to the input gradation value Ai is read from the calibration data DA4 and corrected CMYRVK data. Gradation value.
The PC that performs the process of S120 constitutes a color correction unit that compensates for a shift in CMYRVK data (print data) due to a difference in the color measurement environment with respect to the reference color measurement environment.

  Further, the gradation data of each CMYRVK color constituting the CMYRVK data is obtained by referring to the dot allocation table DA5 while sequentially moving the target pixel using the gradation data of each pixel constituting the CMYRVK data D3 as a conversion target. Then, a dot distribution process for converting a plurality of types of dot formation amounts with different ink amounts into dot amount data D4 to D6 representing the same type is performed (S125). The dot amount data is composed of dot amount data D4 for small dots, dot amount data D5 for medium dots, and dot amount data D6 for large dots for each color. Similar to the CMYRVK data, these dot amount data are data in which the image is expressed in gradation for each element color CMYRVK with a large number (predetermined number) of pixels in the form of a dot matrix. It is assumed that the data is CMYRVK 256-gradation data representing the ink usage amount of each dot ejected from.

  Thereafter, for each pixel constituting the dot amount data D4 to D6, predetermined halftone processing such as an error diffusion method, a dither method, and a density pattern method is performed on the dot amount data for each dot size to obtain CMYRVK data. CMYRVK-specific halftone data having the same number of pixels as D3 is generated (S130). The halftone data is data representing the dot formation status as the presence / absence of dot formation. For example, the gradation value “1” is binarized by corresponding to dot formation and the gradation value “0” corresponding to no dot formation. Two-level binary data can be obtained. Of course, it is good also as data of 4 gradations.

The generated halftone data is subjected to predetermined rasterization processing and rearranged in the order used by the printer to generate raster data for each CMYRVK (S135) and output to the printer 20 (S140). End the flow. Then, the printer 20 obtains raster data representing an image, drives the print head based on these data, ejects ink, and deposits it on the print medium M3, and print image I1 corresponding to the RGB data D1. Form. Since the raster data is data that compensates (reduces) the color shift of the print image due to the difference in the color measurement back material (color measurement environment), the print image I1 corresponds to the reference color measurement back material (reference color measurement environment). An image in which color shift due to a difference in colorimetric back material (colorimetric environment) is compensated is obtained.
The PC that performs the processes of S125 to S140 constitutes a print control unit that performs control for causing the printing apparatus to print a print image corresponding to the print data in which the deviation is compensated.
If the printer can execute halftone processing, it is only necessary to send multi-tone dot amount data to the printer and execute printing based on the dot amount data.

(2) Calibration data creation process:
FIG. 10 is a flowchart showing a reference color measurement result generation process performed by the PC 60, and FIGS. 11 to 13 are flowcharts showing a calibration data creation process performed by the PC 10. In the present embodiment, the PC 60 that performs the processing of FIG. 10 constitutes a reference color measurement result acquisition unit, the PC 10 that performs the processing of S305 to S320 constitutes a color measurement result acquisition unit, and the PC 10 that performs the processing of S325 to S335. It constitutes color correction means.
First, the PC 60 accepts a selection input of a target printer for obtaining a reference color measurement result from a mouse or a keyboard (S205). Next, a printing and colorimetric condition selection process is performed for the selected printer (S210). This process can be performed according to the flow shown in FIG. That is, in S402, a model selection column is displayed or the like, and a selection input of a colorimeter model (type) is received from a mouse or the like, and information representing the selected model is stored in the RAM. In S404, an input for selecting the type of print medium to be colorimetrically received, such as by displaying a print medium selection field, is received from the mouse or the like, and information indicating the type of the selected print medium is stored in the RAM. In step S406, a print quality selection field is displayed, for example, and a patch print quality selection input is received from a mouse or the like, and information indicating the selected print quality is stored in the RAM. In S408, an operation input of the environmental temperature to be measured by displaying a temperature input column or the like is received from a keyboard or the like, and information indicating the input environmental temperature is stored in the RAM. In S410, an operation input of environmental humidity to be measured by displaying a humidity input column or the like is received from a keyboard or the like, information indicating the input environmental humidity is stored in the RAM, and the flow is terminated. Note that the types of print media include glossy paper, plain paper, and recycled paper. Print quality includes high quality, standard quality, and the like.
When the printing and colorimetric condition selection processing is completed, control is performed to cause the printer that has received the selection input to print a color chart corresponding to the type of print medium that has received the selection input and the selected print quality (S215). .

  FIG. 14 shows an example of a color chart printed on the print medium M4. The color chart CH is composed of a plurality of patches P4 arranged in a matrix with no gaps in the vertical and horizontal directions. In the color chart CH, a plurality of empty patches P4a in which no ink is ejected and the surface of the printing medium M4 appears as it is are provided. In the HD of the PC 60, chart data representing the color chart CH (for example, CMYRVK data) is stored for each type of print medium and each print quality. In S215, the chart data corresponding to the type of print medium and the print quality is stored. Then, the processing of S125 to S140 is performed to send the raster data to the printer. Then, the printer ejects ink based on the input raster data to form ink dots on the print medium M4, and prints the color chart CH represented by the chart data on the print medium M4.

Thereafter, a print medium on which a plurality of patches are formed is placed on the surface of the reference colorimetric back material, and each patch on the print medium is measured in the Lab color space (predetermined color space) using the colorimeter 90. In the PC 60, the color component amounts L, a, and b for each patch are used as reference colorimetric results LSi, aSi, bSi (i = 1 to n, n is a positive integer representing the patch number) from the colorimeter 90. Obtained and stored in the RAM (S220). For example, a button for confirming that the color measurement operation for the patch has been completed is displayed on the display, and when a mouse operation for the button is accepted, a signal for outputting the color measurement result to the colorimeter is transmitted and transmitted. It is possible to obtain a color measurement result output from the color measuring device later. The same applies to the following.
The color component amounts L, a, and b are the L amount, a amount, and b amount, which are color values that define the CIE (1976) Lab color space defined in JIS Z8105. The same applies to the following. The colorimetric data obtained here is a standard colorimetric result obtained by measuring the color of a patch on a print medium with a standard colorimetric back material (standard colorimetric environment).

  After completion of S220, the reference colorimetry results LSi, aSi, bSi and the various incidental information input in S210 are associated with each other and stored in the HD (S225). Then, the reference colorimetry results LSi, aSi, bSi are associated with the various accompanying information and output to the outside (S230), and the reference colorimetry result generation process is terminated. The process of S230 is a process of outputting a reference color measurement result and accompanying information to the PC 10 via the communication line 98, and a reference color measurement for a device that writes data to a computer-readable recording medium such as a CD-ROM. A process of outputting the result and accompanying information can be performed.

In the PC 10 that performs calibration data creation processing, the reference colorimetry result and the various kinds of information are obtained in advance by acquiring the reference colorimetry results LSi, aSi, bSi and the various accompanying information via the communication line 98 or the like. Assume that the accompanying information is stored in the HD 14 in association with it.
First, the PC 10 receives a selection input of a target printer from which a color measurement result is acquired from a mouse or a keyboard (S305). Next, the printing and colorimetric condition selection processing shown in FIG. 12 is performed for the selected printer (S310). Further, control is performed to cause the printer that has received the selection input to print a color chart corresponding to the type of print medium that has received the selection input and the selected print quality (S315). Chart data (for example, CMYRVK data) 14d representing the color chart CH is also stored in the HD 14 of the PC 10 for each type of print medium and each print quality. In S215, chart data 14d corresponding to the type of print medium and the print quality is stored. On the other hand, the processing of S125 to S140 is performed to send the raster data to the printer. Then, the printer prints the same color chart CH as the color chart printed by the reference printing system 100a on the print medium M4.

After that, the print medium on which a plurality of patches are formed is placed on the surface of the colorimetric back material (different from the reference colorimetric back material), and each color on the print medium is labeled Lab color using the colorimeter 40. Color measurement is performed in space, and the PC 10 uses the color component amounts L, a, and b for each patch as the color measurement results LMi, aMi, bMi to be compensated (i = 1 to n, n is a positive integer representing the patch number). Is acquired from the colorimeter 40 and stored in the RAM (S320). The colorimetric data obtained here is a colorimetric result of a compensation object obtained by measuring the color of the patch on the print medium with a colorimetric back material (colorimetric environment) different from the reference colorimetric back material.
After S320 ends, colorimetric result correction processing is performed (S325).

In the colorimetric result correction process shown in FIG. 13, first, ground colorimetric values LM0, aM0, and bM0 in the compensation printing system 100b are calculated from the colorimetric results LMi, aMi, and bMi to be compensated. The result is calculated (S502). As shown in FIG. 14, the color chart CH is provided with a plurality of empty patches P4a. In this embodiment, the colorimetric results of these empty patches P4a are averaged by, for example, arithmetic averaging to obtain LM0, aM0, and bM0.
Next, the ground color measurement values LS0, aS0, bS0 in the reference printing system 100a are calculated from the standard color measurement results LSi, aSi, bSi as the standard ground color measurement results (S504). In the present embodiment, LS0, aS0, and bS0 are obtained by averaging the colorimetric results of a plurality of empty patches by, for example, arithmetic averaging.

Further, for a plurality of patches excluding all the empty patches from the color chart, the brightness component difference dLi, the a value difference dai, and the b value difference dbi are calculated for each patch (S506). here,
dLi = LSi-LMi (1)
dai = aSi-aMi (2)
dbi = bSi−bMi (3)
LSi is the brightness component of the reference color measurement result, LMi is the brightness component of the color measurement result to be compensated, aSi, bSi are the saturation components of the reference color measurement result, aMi, bMi ... the color measurement result of the compensation target Is the saturation component. Thereby, the difference dLi, dai, dbi of the color measurement results is obtained for each color measurement result LMi, aMi, bMi of the patch.

Thereafter, in order to sequentially correct the color measurement results to be compensated, the color measurement results LMi, aMi, and bMi to be corrected are set (S508). For example, the color measurement result to be corrected is set from among the plurality of color measurement results by updating the value of the pointer storing the numerical value i corresponding to each of the plurality of color measurement results LMi, aMi, and bMi. .
Then, the compensation color measurement results LMi, aMi, bMi, the compensation color measurement results LM0, aM0, bM0, the standard color measurement results LS0, aS0, bS0, the difference dLi of the color measurement results , dai, dbi, etc., and the compensated colorimetric results LCi, aCi, bCi are calculated (S510). Here, when the correction values for LMi, aMi, and bMi are expressed by ΔLi, Δai, and Δbi, LCi, aCi, and bCi are obtained by the following equations.
LCi = LMi + ΔLi (4)
aCi = aMi + Δai (5)
bCi = bMi + Δbi (6)
Hereinafter, how the correction is performed will be described in detail.

FIGS. 15 and 16 are diagrams for explaining colorimetric value deviation compensation due to the difference in the colorimetric back material.
From the L-ΔL graph of FIG. 5, if the lightness of the colorimetric back material surface is different, the lightness component difference | ΔL | increases as the lightness L increases. Therefore, as shown in the upper part of FIG. 15, in the above correction, the compensation amount | ΔLi _bLL | of the lightness component in the relatively bright first brightness range R1 is compared for the color represented by the color measurement result. The lightness component LMi of the colorimetric result is corrected so as to be larger than the compensation amount | ΔLi _bLL | of the lightness component in the second dark brightness range R2. The compensation amount | ΔLi _bLL | is an absolute value of the correction value ΔLi _bLL for the deviation of the lightness component of the colorimetric result due to the difference in lightness of the colorimetric back material surface.
Here, the first brightness range R1 is set as a range (bright range) whose brightness is larger than the second brightness range R2, in other words, the second brightness range R2 is the first brightness range R1. Is set as a range having a lower brightness (dark range). For example, assuming that the maximum value of lightness L in the Lab color space is Lmax, color measurement is performed when 0 ≦ LMi <Lth using a predetermined lightness threshold value Lth (0 <Lth <Lmax, for example, Lth = Lmax / 2). When the result is in the second brightness range R2 and Lth ≦ LMi ≦ Lmax, the color measurement result can be assumed to be in the first brightness range R1. Of course, 0 ≦ LMi ≦ Lmax / 3 may be set as the second brightness range, Lmax × 2/3 ≦ LMi ≦ Lmax may be set as the first brightness range, and the like. In this embodiment,
ΔLi _bLL = dLi × (LMi / LS0) (7)
Thus, the above correction is performed. That is, for the color represented by the color measurement result, the brightness component LMi of the color measurement result is corrected so that the compensation amount of the brightness component increases as the brightness increases. Here, as the brightness increases, the compensation amount of the brightness component may be increased linearly and proportionally, but as the brightness increases, the compensation amount of the brightness component may be increased stepwise or in a curve.
As described above, it is possible to appropriately compensate for the deviation of the brightness component generated in the color represented by the color measurement result due to the difference in the color measurement flooring material.

From the C-ΔC graph of FIG. 5, if the lightness of the colorimetric back material surface is different, the saturation component difference | ΔC | increases as the saturation C increases. Therefore, as shown in the middle and lower parts of FIG. 15, in the above correction, the saturation components of the first saturation range R3, R5 having a relatively large saturation for the color represented by the color measurement result. The compensation amounts | Δai _bCC | and | Δbi _bCC | are made larger than the compensation amounts | Δai _bCC | and | Δbi _bCC | for the saturation components in the second saturation ranges R4 and R6 where the saturation is relatively small. Correct the saturation components aMi and bMi of the colorimetry result. The compensation amounts | Δai _bCC | and | Δbi _bCC | are the absolute values of the correction values Δai _bCC and Δbi _bCC with respect to the shift of the saturation component of the color measurement result due to the difference in lightness of the color measurement back material surface.
Here, the first saturation range R3, R5 is set as a range in which the saturation is larger than the second saturation range R4, R6, in other words, the second saturation range R4, R6 is the first saturation range. It is set as a range in which the saturation is smaller than the degree ranges R3 and R5. For example, the maximum value of the a and b values in the Lab color space is set to amax and bmax, and threshold values ath (0 <ath <amax. For example, ath = amax / 2) and bth (0 <bth <bmax. bth = bmax / 2), and when 0 ≦ aMi <ath, 0 ≦ bMi <bth, the colorimetric result is in the second saturation range R4, R6, and ath ≦ aMi ≦ amax, bth ≦ bMi It can be assumed that the colorimetric result is in the first saturation range R3, R5 when ≦ bmax. Of course, 0 ≦ aMi ≦ amax / 3, 0 ≦ bMi ≦ bmax / 3 is the second saturation range, amax × 2/3 ≦ aMi ≦ amax, bmax × 2/3 ≦ bMi ≦ bmax is the first saturation It is good also as a range. In the present embodiment, ak and bk are set as predetermined constants other than 0, and the above correction is performed in the following relationship.
Δai _bCC = dLi × (aMi / ak) (8)
Δbi _bCC = dLi × (bMi / bk) (9)

Here, the predetermined constants ak and bk are measured by using a color measuring back material having a black surface and a color measuring back material having a white surface and changing only the color measuring back material in the reference printing system 100a. The color machine 90 can measure the color of a patch on the same print medium, and can determine the color using the obtained color measurement value. As a very simple method, Lb, ab, and bb are the colorimetric results of the patch when using a colorimetric back with a black surface, and the colorimetric of a patch when using a colorimetric back with a white surface. If the result is Lw, aw, bw,
ak = (aw−ab) / ab or ak = (aw−ab) / aw (10)
bk = (bw−bb) / bb or bk = (bw−bb) / bw (11)
It can be. In addition, the colorimetric result of the patch when using the colorimetric back material with the black surface is Lbi, abi, bbi, and the colorimetric result of the patch when using the colorimetric back material with the white surface is Lwi, As awi and bwi, ak and bk may be determined using a least square method. For ak, a correlation equation of y = Ax + B can be obtained by a least square method with abi or awi as a variable x and (awi-abi) as a variable y, and 1 / A can be ak. For bk, bbi or bwi is a variable x, (bwi−bbi) is a variable y, a correlation equation y = Ax + B is obtained by the least square method, and 1 / A can be bk.
As described above, the saturation components aMi and bMi of the color measurement result are corrected so that the saturation amount of the color represented by the color measurement result increases as the saturation increases. Here, not only the saturation component compensation amount increases linearly and proportionally as the saturation increases, but also the saturation component compensation amount increases stepwise or in a curve as the saturation increases. Good.
As described above, it is possible to appropriately compensate for the shift of the saturation component that occurs in the color represented by the color measurement result due to the difference in the color measurement flooring material.

Note that even if the surface of the colorimetric back material or the reference colorimetric back material is gray, the brightness difference dLi increases or decreases depending on the gray level, so the above equations (8) and (9) are used as they are. Can do. That is, if the difference in lightness of the surface between the colorimetric back material and the reference colorimetric back material is dLs, the difference in lightness is dLs when the surface of one back material is black and the surface of the other back material is white. Is the maximum dLsmax. When the surface of one of the backing materials becomes gray, the difference in brightness dLs becomes smaller than the maximum dLsmax, but the difference in the saturation component between the standard colorimetric result and the colorimetric result to be compensated also depends on the brightness of the backing material surface. The difference becomes smaller according to the difference dLs, and is roughly proportional to dLs / dLsmax. Therefore, the above equations (8) and (9) are suitable correction equations.
As described above, in the present embodiment, the difference in brightness component (brightness difference dLi) between the reference color measurement result and the compensation color measurement result is obtained, and the color measurement result is calculated based on the obtained brightness component difference. The color measurement result is corrected so as to compensate for the shift of the saturation component. Since the color shift of the saturation component is compensated not only based on the difference in the saturation component but also on the difference in the brightness component, the saturation component generated in the color represented by the color measurement result due to the difference in the colorimetric covering material. The deviation can be compensated appropriately.

From the L-ΔC graph of FIG. 5, if the lightness of the colorimetric back material surface is different, the difference | ΔC | of the saturation component increases as the lightness L increases. Therefore, as shown in FIG. 16, in the correction, the saturation component compensation amount | Δai _bLC |, | Δbi for the color represented by the color measurement result in the relatively bright first brightness range R7. _BLC | relatively dark compensation amount of the second luminance component in the brightness range _{R8 | Δai bLC |, | Δbi} bLC | so as to be larger than, modify the color measurement result saturation component AMI, the Bmi. The compensation amounts | Δai _bLC | and | Δbi _bLC | are the absolute values of the correction values Δai _bLC and Δbi _bLC for the shift of the saturation component of the color measurement result due to the difference in lightness of the color measurement back material surface.
Here, the brightness ranges R7 and R8 are set in the same manner as the brightness ranges R1 and R2. In the present embodiment, the correction values for the deviation of the colorimetric result due to the difference in lightness of the colorimetric back material surface are Δai _b and Δbi _b , from the above formulas (8) and (9),
Δai _b = Δai _bCC × (LMi / LS0)
= DLi x (aMi / ak) x (LMi / LS0) (12)
Δbi _b = Δbi _bCC × (LMi / LS0)
= DLi x (bMi / bk) x (LMi / LS0) (13)
Thus, the above correction is performed. That is, for the color represented by the color measurement result, the saturation components aMi and bMi of the color measurement result are corrected so that the compensation amount of the saturation component increases as the lightness increases. Here, as the lightness increases, the compensation amount of the saturation component may be increased linearly and proportionally, and as the lightness increases, the compensation amount of the saturation component may be increased stepwise or in a curve.
As described above, it is possible to appropriately compensate for the shift of the saturation component that occurs in the color represented by the color measurement result due to the difference in the color measurement flooring material.

FIGS. 17 and 18 are diagrams for explaining colorimetric value deviation compensation due to a difference in print media.
From the C-ΔC graph of FIG. 6, when the printing medium on which the patch is printed is different, the saturation component difference | ΔC | decreases as the saturation C increases, and the saturation component difference is 0 at a certain saturation Cm or higher. become. Therefore, as shown in FIG. 17, when compensating for the shift in the color measurement result due to the difference in the printing medium, the first saturation range R9, where the saturation of the color represented by the color measurement result is relatively large. compensation amount of the saturation component in the _{R11 | Δai mCC |, | Δbi} mCC | saturation is relatively small second chroma range R10, compensation amount of the saturation component in the _{R12 | Δai mCC |, | Δbi} mCC | than The saturation components aMi and bMi of the colorimetry result are corrected so that the value is also reduced. The compensation amounts | Δai _mCC | and | Δbi _mCC | are the absolute values of the correction values Δai _mCC and Δbi _mCC for the shift of the saturation component of the colorimetric result due to the difference in the print medium on which the patch is formed.
Here, the first saturation ranges R9 and R11 are set in the same manner as the first saturation ranges R3 and R5, and the second saturation ranges R10 and R12 are the same as the second saturation ranges R4 and R6. Is set.
In the present embodiment, am and bm are set as positive predetermined constants, and the above correction is performed in the following relationship.
When the saturation component | aMi | is greater than or equal to the predetermined saturation | am |
Δai _mCC = 0
When the saturation component | aMi | is less than or equal to the predetermined saturation | am |
Δai _mCC = dai × {(am− | aMi |) / am} (14)
When the saturation component | bMi | is greater than or equal to the predetermined saturation | bm |
Δbi _mCC = 0
When the saturation component | bMi | is less than or equal to the predetermined saturation | bm |
Δbi _mCC = dbi × {(bm− | bMi |) / bm} (15)

Here, the predetermined constants am and bm are the reference colorimetry by the colorimeter 90 using a plurality of printing media having different saturation components of the ground color and changing only the printing medium on which the patch is formed in the reference printing system 100a. It is possible to measure the color of the patch on each print medium arranged on the surface of the back material and determine the color using the obtained color measurement value. As a very simple method, if the same color chart is formed on print media having different background color saturation components and the colorimetric results obtained by the colorimeter 90 are LM1i, aM1i, bM1i, LM2i, aM2i, bM2i, respectively, aM1i The minimum aM1i where = M2i can be set as am, and the minimum bM1i where bM1i = bM2i can be set as bm.
Also, am and bm may be determined using the method of least squares. As for am, it is possible to obtain a correlation equation y = Ax + B by the method of least squares with aM1i or aM2i as a variable x and | aM1i−aM2i | as a variable y, and | 1 / A | can be set as am. For bm, bM1i or bM2i is a variable x, | bM1i−bM2i | is a variable y, a correlation equation y = Ax + B is obtained by the least square method, and | 1 / A | can be bm.
As described above, when compensating for the shift in the color measurement result due to the difference in the print medium on which the patch is formed, the saturation of the color represented by the color measurement result increases as the saturation is within a predetermined saturation. The saturation components aMi and bMi of the color measurement result are corrected so as to reduce the component compensation amount. Here, not only the saturation component compensation amount decreases linearly as the saturation increases, but also the saturation component compensation amount may decrease stepwise or in a curve as the saturation increases.
As described above, it is possible to more appropriately compensate for the shift of the saturation component that occurs in the color represented by the color measurement result due to the difference in the print medium.

  In addition, when compensating for deviations in colorimetric results due to differences in print media on which patches are formed, the colorimetric results only when the color represented by the colorimetric results is less than or less than a predetermined saturation am, bm To correct. Thereby, the process which corrects a colorimetric result can be sped up.

From the L-ΔC graph of FIG. 6, if the printing medium on which the patch is printed is different, the difference | ΔC | of the saturation component increases as the lightness L increases. Therefore, as shown in FIG. 18, when compensating for the shift in the color measurement result due to the difference in the print medium, the saturation component in the relatively bright first brightness range R13 for the color represented by the color measurement result. the compensation amount _{| Δai mLC |, | Δbi mLC} | a relatively dark compensation amount of the second luminance component in the brightness range _{R14 | Δai mLC |, | Δbi} mLC | so as to be larger than, colorimetry results Correct saturation components aMi and bMi. The compensation amounts | Δai _mLC | and | Δbi _mLC | are absolute values of the correction values Δai _mLC and Δbi _mLC with respect to the shift of the saturation component of the color measurement result due to the difference in the print medium.
Here, the brightness ranges R13 and R14 are set in the same manner as the brightness ranges R1 and R2. In the present embodiment, correction values for deviations in colorimetric results due to differences in print media are Δai _m and Δbi _m , from the above equations (14) and (15),
When the saturation component | aMi | is greater than or equal to the predetermined saturation | am |
Δai _m = 0
When the saturation component | aMi | is less than or equal to the predetermined saturation | am |
Δai _m = Δai _mCC × (LMi / LS0)
= Dai × {(am− | aMi |) / am} × (LMi / LS0) (16)
When the saturation component | bMi | is greater than or equal to the predetermined saturation | bm |
Δbi _m = 0
When the saturation component | bMi | is less than or equal to the predetermined saturation | bm |
Δbi _m = Δbi _bCC × (LMi / LS0)
= Dbi × {(bm− | bMi |) / bm} × (LMi / LS0) (17)
Thus, the above correction is performed. That is, when compensating for the shift in the color measurement result due to the difference in the print medium on which the patch is formed, for the color represented by the color measurement result, the compensation amount of the saturation component is increased as the brightness increases. Correct the saturation components aMi and bMi of the colorimetry result. Here, as the lightness increases, the compensation amount of the saturation component may be increased linearly and proportionally, and as the lightness increases, the compensation amount of the saturation component may be increased stepwise or in a curve.
As described above, it is possible to appropriately compensate for the shift of the saturation component that occurs in the color represented by the color measurement result due to the difference in the print medium.

In S510 of FIG. 13, the correction described above is performed collectively.
For the lightness component, the lightness component LCi of the colorimetric result after compensation is obtained from the above equations (4) and (7) using the following equations.
LCi = LMi + ΔLi _bLL
= DLi x (LMi / LS0) (18)
For the a component, the a component aCi of the colorimetric result after compensation is obtained from the above equations (5), (12), and (16) using the following equation.
aCi = aMi + Δai _b + Δai _m
= AMi + dLi x (aMi / ak) x (LMi / LS0)
+ Dai × {(am− | aMi |) / am} × (LMi / LS0) (19)
For the b component, the b component bCi of the colorimetric result after compensation is obtained from the above equations (6), (13), and (17) using the following equations.
bCi = bMi + Δbi _b + Δbi _m
= BMi + dLi x (bMi / bk) x (LMi / LS0)
+ Dbi × {(bm− | bMi |) / bm} × (LMi / LS0) (20)
Of course, in S510, only a part of each correction described above may be performed.

As described above, the reference color measurement result and the color measurement result to be compensated are compared, and based on the comparison result, the difference in the color measurement back material (color measurement environment) with respect to the reference color measurement back material (reference color measurement environment). Deviations in colorimetric results are compensated, and deviations in colorimetric results due to differences in print media are compensated. Accordingly, the color represented by the color measurement result is a color in which the color shift due to the difference in the color measurement back material (color measurement environment) is compensated and the color shift due to the difference in the print medium is compensated.
If print media with the same ground color but different thickness and different transparency are used, the ground color measurement results LM0, aM0, bM0 to be compensated and the reference ground color measurement results LS0, aS0, bS0 are obtained. Therefore, even if the color of the colorimetric flooring surface is the same, the ground color correction alone will cause a difference in the color transmission level of the colorimetric flooring surface due to the difference in the thickness (transmission level) of the print medium. It is not possible to compensate for the resulting colorimetric result deviation. In the above-described correction, even if print media having the same ground color with different degrees of transmission are used, it is possible to compensate for a shift in the color measurement results caused by a difference in the degree of color transmission on the surface of the color measurement flooring.
Of course, the color measurement result to be compensated may be acquired by the color measuring device 40 of the compensation printing system 100b using the printing medium on which the color chart is printed by the printer 70 of the reference printing system 100a. Then, a shift in the color measurement result due to a difference in color on the surface of the color measurement flooring can be compensated with high accuracy.

After completion of S510, it is determined whether or not all the color measurement results have been set (S512). If the condition is not satisfied, S508 to S512 are repeated, and if the condition is satisfied, the color measurement result correction process is terminated.
Thereafter, in S330 of FIG. 11, the color measurement results LS2i, aS2i, and bS2i of the second standard that is used as a color matching standard are acquired. Next, using the reference colorimetric results LS2i, aS2i, bS2i and the compensated colorimetric results LCi, aCi, bCi, the color of the patch that obtained the compensated colorimetric results LCi, aCi, bCi Processing for creating calibration data for correcting to the colors represented by the colorimetry results LS2i, aS2i, bS2i is performed (S335).

FIG. 19 schematically shows a state in which the color measurement result after compensation (black circle) and the second reference color measurement result (white circle) to be matched are associated with C ink as an example. Here, the horizontal axis is the a value defined in the Lab color space, the vertical axis is the b value, and the colorimetric values are projected onto the ab plane. Both colorimetric results are shown connected by curves. The numerical value in the enlarged view A1 indicates the gradation value.
Here, a curve connecting the compensated color measurement results is obtained by a predetermined interpolation calculation, and the color measurement results on this curve are LC, aC, bC, and a curve connecting the second reference color measurement results for matching colors is obtained. The color measurement result obtained by a predetermined interpolation operation is defined as LS2, aS2, bS2, and the color difference between the compensated color measurement result and the reference color measurement result ΔE = {(LC−LS2) ² + (aC− aS2) ² + (bC−bS2) ² } ^1/2
Is correlated with the reference color measurement result and the compensated color measurement result so that calibration data is generated.

Referring to the calibration data DA4 in FIG. 7, the input tone value is a tone value representing the color represented by the color measurement result after compensation, and the output tone value is the second reference measurement value. The calibration data DA4 is created so as to be closest to the gradation value expressing the color represented by the color result. For example, when the gradation value is set to increase the degree of color development of the printed image, the color represented by the color measurement result after compensation is the color represented by the second reference color measurement result. If the degree of color development is smaller than that, the calibration data is created so that the output gradation value is larger than the input gradation value as an overall tendency so as to increase the degree of color development of the printed image. Then, by referring to such calibration data, the CMYRVK data is corrected so that the degree of color development on the print medium is increased. On the other hand, if the color represented by the color measurement result after compensation is higher than the color represented by the color measurement result of the second reference, it is used for calibration so as to reduce the color development degree of the printed image. The data is created so that the output tone value is smaller than the input tone value as a whole trend. By referring to such calibration data, the CMYRVK data is corrected so that the degree of color development on the print medium is reduced.
In the calibration data DA4 created as described above, the color represented by the input gradation value is the color represented by the color measurement result after compensation, and the color represented by the output gradation value is the first color. The information table is a color represented by the color measurement result of the second reference.
As described above, a print image that is color-compensated so as to match the color represented by the second reference color measurement result can be formed on the print medium.
Of course, the calibration data can be created by various methods.

After completion of S335, the generated calibration data is stored in the HD 14 (S340), and the calibration data creation process is terminated.
Thereafter, when the print control process shown in FIG. 8 is performed by the PC 10, the printer 20 performs color due to a difference in the color measurement back material (color measurement environment) with respect to the reference color measurement back material (reference color measurement environment). An image in which the deviation is compensated can be formed on the print medium.

  As described above, the color represented by the color measurement result after compensation is a color in which the color shift due to the difference in the color measurement environment is compensated and the color shift due to the difference in the print medium is compensated. Therefore, it is possible to compensate for the color shift due to the difference in the environment for measuring the color of the image on the print medium and the color shift due to the difference in the print medium, and color reproduction with respect to the reference color for the color represented by the color measurement result (color data). It becomes possible to improve the property.

(3) Modification:
By the way, various configurations are possible for the computer and the peripheral device that can be used in carrying out the present invention. For example, the printing apparatus may be integrated with a computer. A printing apparatus that prints only a single color image may be used. Some or all of the above-described flows may be executed by a printing apparatus, a dedicated image processing apparatus, an external server, or the like.
As a colorimetric environment to compensate for color misregistration, environmental temperature, environmental humidity, and the like may be included in addition to the colorimetric back material. Even in these cases, the difference in the color data due to the difference in the colorimetric environment can be compensated by the same process as described above.
In the above-described embodiment, brightness is used as brightness. However, brightness may be brightness, a combination of X value, Y value, and Z value defined in the XYZ color space, darkness such as Lmax-L, and the like.
In the above-described embodiment, the a value and the b value defined in the Lab color space are used as the saturation component. However, the u value and the v value defined in the Luv color space may be used as the saturation component.
In the case of using an automatic colorimeter that automatically and sequentially measures an image on a printing medium arranged on the surface of the color measuring back material as the color measuring devices 40 and 90, the color measuring is performed in S220 of FIG. 10 or S320 of FIG. When acquiring the result, the colorimetry result may be generated from the automatic colorimeter after the process of measuring the color of each patch is performed on the automatic colorimeter to generate the colorimetry result.

  Further, the color data to be compensated for deviation may be, for example, print data representing a print image, a calibration one-dimensional LUT, a color conversion LUT, a dot distribution table, and the like other than the color measurement result.

FIG. 20 is a flowchart illustrating print control processing performed by the color misregistration compensation device according to the modification. In this modification, the color data generation device is a print control device, and the color data is RGB data (print data). Here, the PC 10 that performs the processes of S105 to S110, S115, and S125 to S140 constitutes a print control means, and the PC 10 that performs the processes of S152 to S158 constitutes a color correction means. As a premise of performing this process, the process of FIG. 10 is performed to generate a reference color measurement result, and the processes of S305 to S320 of FIG. 11 and S502 to S506 of FIG. It is assumed that it has been acquired.
First, in S105 to S110, the printer and printing conditions are acquired, and image data is input to generate RGB data. Next, the RGB data is color-converted into Lab data composed of L value, a value, and b value defined in the Lab color space by using a predetermined conversion formula (S152). Further, the L value, a value, and b value of the Lab data are set as LMi, aMi, bMi, and the colorimetric results LMi, aMi, bMi to be compensated associated with each patch i and the reference colorimetric results LSi, aSi, Based on bSi, reference colorimetric results LSi, aSi, bSi corresponding to Lab data are acquired (S154). Then, LCi, aCi, bCi are calculated using the colors (18) to (20), and the calculated values are used as compensated Lab data (S156).

When the Lab data shift is compensated, the compensated Lab data is color-converted into RGB data by using a predetermined conversion formula (S158).
As described above, the reference color measurement result is compared with the color measurement result to be compensated, and the deviation of the print data due to the difference in the color measurement environment with respect to the reference color measurement environment is compensated from the comparison result.
After that, RGB data is color-converted into CMYRVK data in S115, raster data is generated and sent to the printer 20 in S125 to S140, and an image corresponding to the input image data is printed on the print medium. The print image is appropriately compensated for color misregistration due to differences in the colorimetric environment, and the color reproducibility of the color represented by the print data (color data) representing the print image with respect to the reference color can be improved.

FIG. 21 is a flowchart illustrating calibration data creation processing performed by the color misregistration compensation device according to the modification. In this modification, the color data generation device is a calibration data creation device (color correction data creation device), and the color data is the calibration data (color correction data) DA4 shown in FIG. Here, the PC 10 that performs this processing constitutes a color correction means. As a premise of performing this process, the process of FIG. 10 is performed to generate a reference color measurement result, and the processes of S305 to S320 of FIG. 11 and S502 to S506 of FIG. It is assumed that it has been acquired.
First, a selection input of the printer is received (S602), the printing and colorimetry condition selection processing shown in FIG. 12 is performed (S604), the color chart printing control is performed, and the printer 20 prints the color chart on the printing medium. (S606) A colorimetric result for creating calibration data DA4 is obtained by measuring each patch of the color chart with the colorimeter 40 using a predetermined colorimetric back material (S608). . Also, the color measurement results LS2i, aS2i, and bS2i of the second standard, which is a standard for matching colors, are acquired (S610). Next, using the colorimetry results acquired in S608 and S610, the color of the patch obtained in S608 is corrected to the color represented by the second reference colorimetry results LS2i, aS2i, bS2i. A process of creating calibration data is performed (S612). The calibration data created here is data that is not compensated for a shift due to a difference in colorimetric back material (colorimetric environment) or the like, and will be referred to as calibration data to be compensated.

  After that, by using a predetermined conversion formula or the like, input side data composed of input gradation values for each color of calibration data to be compensated is converted into Lab composed of L value, a value, and b value defined in the Lab color space. Color conversion into data is performed (S614). Further, the L value, a value, and b value of the Lab data are set as LMi, aMi, bMi, and the colorimetric results LMi, aMi, bMi to be compensated associated with each patch i and the reference colorimetric results LSi, aSi, Based on bSi, reference colorimetric results LSi, aSi, bSi corresponding to Lab data are acquired (S616). Then, LCi, aCi, bCi are calculated using the colors (18) to (20), and the calculated values are used as compensated Lab data (S618).

When the Lab data shift is compensated, the compensated Lab data is color-converted to input side data by using a predetermined conversion formula or the like (S620).
As described above, the CMYRVK data (printing) is performed so that the reference color measurement result and the color measurement result to be compensated are compared and the deviation of the calibration data due to the difference in the color measurement environment with respect to the reference color measurement environment is compensated from the comparison result. Data) is defined before and after correction.
The created calibration data is stored in the HD 14 (S622), and the calibration data creation process is terminated.
After that, RGB data is color-converted into CMYRVK data in S115, raster data is generated and sent to the printer 20 in S125 to S140, and an image corresponding to the input image data is printed on the print medium. The printed image is properly compensated for color shifts due to differences in the colorimetric environment, etc., and the color reproducibility of the color represented by the calibration data (color data) that defines the correspondence before and after the correction of the print data with respect to the reference color It becomes possible to improve.

  The color correction data that defines the correspondence before and after the correction of print data includes a plurality of correspondences between RGB data (one type of print data) before color conversion and CMYRVK data (one type of print data) after color conversion. The correspondence relationship between the color conversion table (color conversion data) defined by the reference points, CMYRVK data (one type of print data) before dot distribution and each dot amount data (one type of print data) of CMYRVK after dot distribution A prescribed dot distribution table (dot distribution data) DA5, etc. may be used. Even in these cases, color correction data for appropriately compensating for color misregistration can be created by the same processing as that shown in FIG.

The present invention can also be applied to simple colorimetric comparisons such as the following.
Referring to FIG. 2, a scene of remote proof in which reproduced colors are matched in both the first printing system 100a and the second printing system 100b provided at locations remote from each other is applied to the present invention. Is considered. In this case, if the color measurement result obtained by the first printing system 100a is used as the reference color measurement result, the color measurement result obtained by the second printing system 100b is used as the color measurement result to be compensated, and the second printing system. It is possible to compensate so that the color measurement result of 100b matches the reference color measurement result. On the other hand, if the color measurement result obtained by the second printing system 100b is used as the reference color measurement result, the color measurement result obtained by the first printing system 100a is used as the color measurement result to be compensated, and the first printing system 100a. It is possible to compensate so that the colorimetric result is matched with the reference colorimetric result. Further, if, for example, an average (arithmetic average or the like) of the color measurement results obtained by both the printing systems 100a and 100b is used as the reference color measurement result, the color measurement results obtained by both the printing systems 100a and 100b are used as the colorimetry for compensation. As a result, the color measurement results of both printing systems 100a and 100b can be compensated to match the reference color measurement results. The same can be said when a third or higher printing system is provided.

When the first and second printing systems 100a and 100b, which are remote from each other, are provided, first, it is confirmed whether or not the reproduced colors of the printed images are substantially matched (within an allowable range) in both printing systems. For example, the color measurement results of each patch obtained by the first printing system 100a are represented by LP1i, aP1i, bP1i (i is an integer of 1 to n, n is an integer of 1 or more), and each color obtained by the second printing system 100b. If the colorimetric results of the patches are LP2i, aP2i, and bP2i, the color difference between both colorimetric results of each patch ΔEi = {(LP2i−LP1i) ² + (aP2i−aP1i) ² + (bP2i−bP1i) ² } ^1/2
Is calculated, and it is determined whether or not the reproduced color is correct based on ΔEi. In this determination, an average value (arithmetic average value, etc.) ΔE of ΔEi is obtained, and if ΔE is equal to or smaller than ΔEth as a threshold value ΔEth (for example, ΔEth is 1, 2, 3, 4, etc.) for ΔE, the reproduction color May be determined to be almost the same (within the allowable range).

Here, there is a possibility that the colorimetric environments are different between the printing systems 100a and 100b, that is, when the surface of the colorimetric back material is black while the other is white, both colorimetric backs are used. If the surface of the material is white, but one is worn out and becomes a little black, the surface of both color measuring back materials is black, but the blackness (brightness) is different, etc. . Even in such a case, by applying the present invention and correcting so as to reduce the difference between the colorimetric results of the two printing systems 100a and 100b, whether or not the reproduced colors match by eliminating the difference in the colorimetric environment. It becomes possible to judge.
As described above, according to the present invention, it is possible to compensate for color misregistration due to a difference in the environment for colorimetric measurement of an image on a print medium according to various aspects, and for the color represented by the color data with respect to the reference color. Color reproducibility can be improved.

The figure which shows typically the structure of a color shift compensation apparatus. 1 is a block diagram showing an outline of the configuration of a printing system. 1 is a block diagram showing a configuration of a printing system. The figure which shows the result of having mounted on the back material for a different color measurement, and having measured each patch. The figure explaining the tendency of the shift | offset | difference of the colorimetric value by the difference in the back material for colorimetry. The figure explaining the tendency of the shift | offset | difference of the colorimetric value by the difference in a print medium. The figure which shows typically the data structure of the data for calibration. 6 is a flowchart showing print control processing. The figure which shows a printing control process typically. 5 is a flowchart showing reference color measurement result generation processing. The flowchart which shows the data creation process for calibration. 5 is a flowchart showing printing and colorimetric condition selection processing. 5 is a flowchart showing colorimetry result correction processing. The figure which shows an example of the color chart printed on a printing medium. FIG. 6 is a diagram for explaining compensation for colorimetric value deviation due to a difference in colorimetric back material. FIG. 6 is a diagram for explaining compensation for colorimetric value deviation due to a difference in colorimetric back material. FIG. 6 is a diagram for explaining colorimetric value deviation compensation due to a difference in print media. FIG. 6 is a diagram for explaining colorimetric value deviation compensation due to a difference in print media. The figure which shows a mode that the colorimetry result after compensation and the reference | standard colorimetry result are matched. 9 is a flowchart illustrating a modification of print control processing. The flowchart which shows the modification of the data creation process for calibration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,60 ... Personal computer, 13a, 14b ... Standard color measurement result, 13b, 14c ... Color measurement result to be compensated, 13c ... Color measurement result after compensation, 14 ... Hard disk, 14a ... Color shift compensation program, 14d ... Chart data 20, 70 ... Inkjet printer, 40, 90 ... Color colorimeter, 40a, 90a ... Detection unit, 100 ... Printing system, B1 ... Standard colorimetric back material (standard colorimetric flooring), B2 ... Color measurement back material (color measurement covering material), CH ... Color chart, DA1 ... Standard color measurement result, DA2 ... Color measurement result to be compensated, DA3 ... Color measurement result after compensation, DA4 ... Calibration Data, DA5 ... dot allocation table, I1 ... print image, M1-M4 ... print medium, P1, P2, P4 ... patch (image), P4a ... empty patch, R1, R7, R 3 ... first brightness range, R2, R8, R14 ... second brightness range, R3, R5, R9, R11 ... first saturation range, R4, R6, R10, R12 ... second saturation Range, U1 ... colorimetry result acquisition unit (colorimetry result acquisition unit), U2 ... color correction unit (color correction unit), U11 ... reference colorimetry result acquisition unit (reference colorimetry result acquisition unit)

Claims (16)

A color misregistration compensator that compensates for color misregistration in a color data generating apparatus that performs colorimetry on an image formed on a print medium and generates color data representing a color corresponding to the image on the print medium,
Color measurement result obtaining means for obtaining a color measurement result of a compensation object obtained by measuring an image on the print medium in a color measurement environment different from a reference color measurement environment used as a standard of an environment for color measurement of the image on the print medium When,
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. A color misregistration compensation device comprising color correction means for compensating for the color data misregistration due to a difference in color environment. The color data generation device is a device that generates the color data by measuring an image on the print medium arranged on the surface of the color measurement flooring, and the color measurement flooring performs the color measurement. Included in the environment,
The color measurement result acquisition means is arranged on the surface of the color measurement flooring material different from the reference color measurement flooring material used as a reference of the color measurement flooring material used for color measurement of the image on the print medium. Obtain the color measurement result of the compensation object that measured the image on the print medium,
The color correction means compares a reference color measurement result obtained by measuring the image on the print medium arranged on the surface of the reference color measurement flooring with a color measurement result to be compensated. The color misregistration compensation apparatus according to claim 1, wherein the color misregistration is compensated for by a difference in the color measuring covering material with respect to the reference color measuring covering material from the comparison result. The surface of the base material for color measurement and the surface of the color measurement material used when obtaining the color measurement result by the color measurement result acquisition means are achromatic colors with different brightness,
The color correction means compensates for a shift in the color data due to a difference in brightness of the surface of the colorimetric covering material relative to the brightness of the surface of the reference colorimetric flooring based on the comparison result. The color misregistration compensation device described in 1.   The color correction means, for the color represented by the color data, the compensation amount of the brightness component in the relatively bright first brightness range from the compensation amount of the brightness component in the relatively dark second brightness range. 4. The color misregistration compensation apparatus according to claim 2, wherein the color data is corrected so as to increase the value.   The color correction means obtains a difference in brightness component between the reference color measurement result and the compensation color measurement result, and based on the obtained difference in brightness component, the color saturation represented by the color data is calculated. 5. The color misregistration compensation apparatus according to claim 2, wherein the color data is corrected so as to compensate for the deviation of the degree component.   The color correction means, for the color represented by the color data, the saturation component compensation amount in the relatively bright first brightness range from the saturation component compensation amount in the relatively dark second brightness range. 6. The color misregistration compensation apparatus according to claim 2, wherein the color data is corrected so as to be larger.   The color correction means is configured to determine a saturation component compensation amount in a first saturation range having a relatively high saturation for the color represented by the color data, in a second saturation range having a relatively low saturation. 7. The color misregistration compensation apparatus according to claim 2, wherein the color data is corrected so as to be larger than the compensation amount of the degree component.   The color correction means compares the reference color measurement result with the color measurement result to be compensated, and the color data shifts due to a difference in the color measurement environment with respect to the reference color measurement environment from the comparison result; and The color data shift due to a difference in a print medium on which an image for obtaining the color measurement result to be compensated for a print medium on which an image obtained from a reference color measurement result is formed is compensated. The color misregistration compensation device according to claim 2.   When the color correction unit compensates for the shift of the color data due to the difference in the print medium on which the image is formed, the first saturation having a relatively large saturation for the color represented by the color data. 9. The color data is corrected so that the compensation amount of the saturation component in the range is made smaller than the compensation amount of the saturation component in the second saturation range where the saturation is relatively small. The described color misregistration compensation device.   When the color correction means compensates for the shift of the color data due to the difference in the print medium on which the image is formed, the color represented by the color data is a color in the relatively bright first brightness range. The color data is corrected so that the compensation amount of the degree component is larger than the compensation amount of the saturation component in the relatively dark second brightness range. Color shift compensation device.   When the color correction means compensates for the shift of the color data due to the difference in the print medium on which the image is formed, the color correction means is only when the color represented by the color data is less than or less than a predetermined saturation. The color misregistration compensation apparatus according to claim 8, wherein the color data is corrected. A color measuring device that generates a color measurement result by measuring a color of an image formed on a print medium,
Color measurement result obtaining means for obtaining a color measurement result of a compensation object obtained by measuring an image on the print medium in a color measurement environment different from a reference color measurement environment used as a standard of an environment for color measurement of the image on the print medium When,
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. A color measurement device comprising color correction means for compensating for a deviation in the color measurement result generated due to a difference in color environment. A print control apparatus that controls a printing apparatus that forms a print image corresponding to print data on a print medium,
Acquire compensation colorimetric results of colorimetric measurement of images formed on the print medium in a colorimetric environment different from the standard colorimetric environment used as the colorimetric environment for the image formed on the print medium. Colorimetric result acquisition means for
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. Color correction means for compensating for the deviation of the print data due to the difference in color environment;
A print control apparatus comprising: a print control unit that performs control for causing the printing apparatus to print a print image corresponding to print data in which the deviation is compensated. A color correction data creation device that creates color correction data that defines a correspondence relationship before and after correction of the print data in order to compensate for color misregistration in a printing device that forms a print image corresponding to the print data on a print medium. ,
Color measurement result obtaining means for obtaining a color measurement result of a compensation object obtained by measuring an image on the print medium in a color measurement environment different from a reference color measurement environment used as a standard of an environment for color measurement of the image on the print medium When,
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. Color correction data comprising color correction means for defining the correspondence before and after the correction of the print data so as to compensate for the deviation of the color correction data due to a difference in color environment and generating the color correction data Creation device. A color misregistration compensation method for compensating for color misregistration in a color data generating device that performs colorimetry on an image formed on a print medium and generates color data representing a color corresponding to the image on the print medium,
A colorimetric result acquisition step of acquiring a colorimetric result of a compensation object obtained by measuring an image on the print medium in a colorimetric environment different from a reference colorimetric environment used as a standard of the colorimetric environment for the image on the print medium When,
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. A color misregistration compensation method comprising: a color correction step of compensating for the color data misregistration due to a difference in color environment. Color misregistration that allows a computer to realize a function of compensating for color misregistration in a color data generating apparatus that generates color data representing a color corresponding to the image on the print medium by measuring the color of an image formed on the print medium A compensation program,
Color measurement result acquisition function for acquiring a color measurement result of a compensation object obtained by measuring an image on the print medium in a color measurement environment different from a reference color measurement environment used as a standard of the environment for measuring the color of the image on the print medium When,
The reference color measurement result obtained by measuring the image on the printing medium in the reference color measurement environment is compared with the color measurement result to be compensated, and the comparison result is used to measure the reference color measurement environment. A color misregistration compensation program for causing a computer to realize a color correction function for compensating for the color data misregistration due to a difference in color environment.

Images