JP2017217789A - Color chart for color selection creation method, and color chart for color selection creation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for creating a color chart for color selection in which color patches are efficiently arranged under conditions where the number of color patches and a color chart area are limited.SOLUTION: A color chart for color selection creation method creates a color chart for color selection for selecting a color patch closest to a target color to be associated with input data from a plurality of color patches. The plurality of color patches includes a first color patch and a second color patch adjacent to each other. The color chart for color selection creation method includes: a determination step of determining a degree of a difference between a present color represented by output data obtained from the input data according to a profile set and the target color; and another determination step of determining at least one of a color difference between the first color patch and the second color patch according to determination by the determination step and the number of color patches included in the color chart for color selection.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a color selection color chart generation method and a color selection color chart generation program.

  For example, print document data is generated using an offset printing machine as a target, the print document data is converted by a RIP (Raster Image Processor), and a printed matter is formed by an inkjet printer. While the color reproduction gamut of offset printers is limited, printing colors targeted for offset printing machines have been replaced with more vivid target colors in order to make wide use of the color reproduction gamut of inkjet printers. ing. The color selection color chart in which a plurality of color patches are formed is used, for example, to select the target color described above. In such a color selection color chart, for example, a plurality of color patches whose colors are gradually changed from the central color are arranged. In the color selection method disclosed in Patent Document 1, color comparison conditions in a color chart are designated, and color patches corresponding to different variables of the designated color comparison conditions are provided so as to be adjacent to each other. Image data for printing the first to third color charts is generated.

  When generating a color selection color chart, it is necessary to determine the number of color patches, the color difference between the color patches, and the size of the color area covered by all the color patches. For example, in order to reduce the number of color patches so that the target color can be easily found, it is necessary to increase the color difference between the color patches or reduce the color coverage area of all the color patches. However, when the color difference between the color patches is increased, it is difficult to find a close color when the target color is the color between the color patches. Further, if the cover area of the colors of all color patches is narrowed, it is difficult to find a close color if the target color does not fall within that area. Thus, there is a trade-off relationship between the number of color patches, the color difference between the color patches, and the size of the cover area.

  When searching for a target color for replacing the current print color, the user searches for a target color patch from a color selection color chart including a color patch of the current print color. When the color patch of the target color is not in the color range of the color chart for color selection, the user increases the color difference between the patches so that the target color is in the color range of the color chart for color selection. Alternatively, it is necessary to increase the color area covered by the color selection color chart by increasing the number of patches included in the color selection color chart. Conversely, if the difference between the target color and the current print color is small, the user can reduce the number of patches included in the color selection color chart to make the print area smaller or match the color in detail. The color difference between patches is reduced.

JP 2011-77937 A

When the user compares the target color with the current print color, the judgment is often wrong, the target color patch is not found in the color selection color chart, and the color difference between the color patches is increased to reprint the color selection color chart. Or printing an unnecessarily large number of patches. As a result, time and print media are wasted in selecting the target color patch.
The above-mentioned problem is not limited to searching for a target color for a printing color targeted for an offset printing machine, but also exists for searching for a target color for various target colors.

  An object of the present invention is to provide a technique for generating a color selection color chart in which color patches are arranged efficiently.

In order to achieve one of the above objects, the present invention provides a color selection color chart for generating a color selection color chart for selecting a color patch having a color closest to a target color associated with input data from a plurality of color patches. A color chart generation method,
The plurality of color patches include a first color patch and a second color patch adjacent to each other,
A determination step of determining the degree of difference between the current color represented by the output data obtained from the input data according to the set profile and the target color;
A determination step of determining at least one of a color difference between the first color patch and the second color patch and the number of color patches included in the color selection color chart according to the determination by the determination step;
It has an aspect containing.

Further, the present invention is a color selection color chart generation program for generating a color selection color chart for selecting a color patch having a color closest to a target color associated with input data from a plurality of color patches. And
The plurality of color patches include a first color patch and a second color patch adjacent to each other,
A determination function for determining the degree of difference between the current color represented by output data obtained from the input data according to a set profile and the target color;
A determination function for determining at least one of a color difference between the first color patch and the second color patch and the number of color patches included in the color selection color chart according to the determination by the determination function;
A mode in which a computer is realized.

  The above-described aspect can provide a technique for generating a color selection color chart in which color patches are efficiently arranged while the number of color patches and the color chart area are limited.

The figure which shows typically the example of the color management flow from manuscript preparation to printing. The figure which shows the example of the color reproduction range shown by the profile typically. The figure which shows typically the example of the printed matter of the color chart for color selection. FIG. 3 is a block diagram schematically illustrating a configuration example of a color adjustment device. 6 is a flowchart illustrating an example of color adjustment processing. The flowchart which shows the example of the color difference determination process between patches. The figure which shows typically the example of the criteria for determining the possibility of the desaturation at the time of print original data generation. The flowchart which shows another example of the color difference determination process between patches. The flowchart which shows another example of the color difference determination process between patches. The flowchart which shows the example of a patch space | interval number determination process. The flowchart which shows another example of the color difference determination process between patches. FIG. 12A is a diagram schematically illustrating an example of a color difference selection screen between patches, and FIG. 12B is a diagram schematically illustrating an example of a patch number selection screen.

  Embodiments of the present invention will be described below. Of course, the following embodiments are merely examples of the present invention, and all the features shown in the embodiments are not necessarily essential to the means for solving the invention.

(1) Overview of this technology:
First, the outline | summary of the technique included in this invention is demonstrated with reference to the example shown by the figure of this application. In addition, the figure of this application is a figure which shows an example typically, The expansion ratio of each direction shown by these figures may differ, and each figure may not match.

[Aspect 1]
The color selection color chart generation method illustrated in FIGS. 1 to 5 includes a determination step ST1 and a determination step ST2, and the color closest to the target color associated with the input data D1 from among the plurality of color patches PA1. A color selection color chart CH1 for selecting the patch PA1 is generated. As illustrated in FIG. 3, the plurality of color patches PA1 include a first color patch P1 and a second color patch P2 that are adjacent to each other. In the determination step ST1, according to the set profile 520, the current color represented by the output data D2 obtained from the input data D1 (for example, a color represented by equation (7) described later) and the target color (for example, described later). And the degree of difference between the color and the color represented by equation (11). In the determination step ST2, according to the determination in the determination step ST1, the color difference d between the first color patch P1 and the second color patch P2, the number N of color patches PA1 included in the color selection color chart CH1, and , At least one of them is determined.

  In the first aspect, the color difference d between the first color patch P1 and the second color patch P2 and the number N of color patches PA1 included in the color selection color chart CH1 according to the degree of difference between the current color and the target color. Are determined, and a color selection color chart CH1 is generated. As a result, the color range of the color selection color chart CH1 can be set in accordance with the degree of difference between the current color and the target color. Therefore, the above-described aspect 1 can provide a method for generating a color selection color chart in which color patches are efficiently arranged while the number of color patches and the color chart area are limited.

Here, the color selection color chart may be formed on a medium such as a print substrate or may be displayed on a display device.
The color difference widely includes a color difference in a uniform color space such as a CIE (International Lighting Commission) L ^* a ^* b ^* color space, and includes a color difference according to the color difference formulas CIEDE2000, CMC, CIEDE94, and the like.
To determine the degree of difference between the current color and the target color, the estimation difference between the current color and the target color is obtained and a determination is made based on the estimation difference, and the estimation between the current color and the target color is performed. Both are determined by different methods without obtaining the difference.

[Aspect 2]
By the way, in the determination step ST1, the difference between the current color and the target color (for example, color difference components ΔL _sim , Δa _sim , Δb _sim represented by equations (12) to (14) described later) is estimated. Good. In the determination step ST1, based on the estimated difference, a degree of difference between the current color and the target color is determined so that the target color is included in the color range of the color selection color chart CH1. (For example, step S240 in FIG. 6). When at least one of the color difference d between the first color patch P1 and the second color patch P2 and the number N of color patches PA1 included in the color selection color chart CH1 is determined according to this determination, the color difference is generated. The target color is included in the color range of the color selection color chart CH1. From this color selection color chart CH1, the user can select a color patch PA1 of the target color. Therefore, this aspect can provide a suitable example in which color patches are efficiently arranged on the color selection color chart.

[Aspect 3]
In the determination step ST2, a plurality of settings for the color difference d between the first color patch P1 and the second color patch P2 may be prepared. As illustrated in FIG. 9, in the determination step ST2, when there are a plurality of settings according to the determination in the determination step ST1 among these settings, the color difference having the smallest color difference among the plurality of settings is set. Alternatively, the color difference d between the first color patch P1 and the second color patch P2 may be determined. As a result, the generated color selection color chart CH1 includes the color patch of the target color, while suppressing the color difference between the first color patch P1 and the second color patch P2 from becoming too large. Therefore, this aspect can provide a more preferable example in which color patches are efficiently arranged on the color selection color chart.

[Aspect 4]
In the determination step ST2, a plurality of settings for the number N of color patches PA1 included in the color selection color chart CH1 may be prepared. As illustrated in FIG. 10, in the determination step ST2, when there are a plurality of settings according to the determination in the determination step ST1 among these settings, the number of the settings with the smallest number among the plurality of settings is set. Alternatively, the number N of color patches PA1 included in the color selection color chart CH1 may be determined. Thus, while the target color patch CH1 is included in the generated color selection color chart CH1, it is suppressed that the number N of color patches PA1 included in the color selection color chart CH1 is too large. Therefore, this aspect can also provide a more preferable example in which color patches are efficiently arranged on the color selection color chart.

[Aspect 5]
In the determination step ST1, in accordance with the set profile 520, a first coordinate value (for example, an expression (4) described later) of the device independent color space (for example, L ^* a ^* b ^* color space) is determined from the input data D1. (L _in , a _in , b _in )) may be obtained. In the determination step ST1, the second coordinate value of the device independent color space (for example, the expression (15) to be described later is expressed from the input data D1 according to the reference profile 511 used to generate the input data D1 ( L _m , a _m , b _m )) may be obtained. Further, in the determination step ST1, based on the difference between the first coordinate value and the second coordinate value (for example, color difference components ΔL _sim , Δa _sim , Δb _sim represented by the equations (16) to (18)). The degree of difference between the current color and the target color may be determined. This aspect can provide a suitable example in which color patches are efficiently arranged in the color chart for color selection when the set profile 520 and the reference profile 511 for generating input data may be different.
Here, the device-independent color space includes CIE L ^* a ^* b ^* color space, CIE L ^* u ^* v ^* color space, and the like, and includes an improved uniform color space based on the color difference formulas CIEDE2000, CMC, CIDEDE94, and the like. .

[Aspect 6]
As illustrated in FIG. 8, in the determination step ST1, it is determined whether or not the input profile 521 included in the set profile 520 is a reference profile 511 used for generating the input data D1. Good. This determination is also included in determining the degree of difference between the current color and the target color. In the determination step ST2, (a) the input difference is more than the color difference d (for example, 1.0) between the first color patch P1 and the second color patch P2 when the input profile 521 is the reference profile 511. When the profile 521 is not the reference profile 511, the color difference d (for example, 2.0) between the first color patch P1 and the second color patch P2 may be increased. In the determination step ST2, (b) the number N (for example, 9 × 9 × 9) of color patches PA1 included in the color selection color chart CH1 when the input profile 521 is the reference profile 511. The number N (for example, 17 × 17 × 17) of color patches PA1 included in the color selection color chart CH1 when the input profile 521 is not the reference profile 511 may be increased.

  When the input profile 521 is the reference profile 511, the difference between the current color and the target color is likely to be relatively small. On the other hand, when the input profile 521 is not the reference profile 511, the difference between the current color and the target color may be relatively large. When at least one of the components (a) and (b) is performed, the color range of the color selection color chart CH1 is relatively large when the difference between the current color and the target color may be relatively large. Become wider. Therefore, this aspect can provide a suitable example in which color patches are efficiently arranged on the color selection color chart.

[Aspect 7]
The input data D1 may include data representing usage amounts (for example, process colors CMYK _in ) of a plurality of color materials used in the target device (for example, the target printing machine 580). In the determination step ST1, the degree of difference between the current color and the target color may be determined based on the usage amounts of a plurality of color materials represented by the input data D1 (for example, step S220 in FIG. 6). ). This aspect can also provide a suitable example in which color patches are efficiently arranged on the color selection color chart.

Here, the target device includes an offset printing machine, a gravure printing machine, a flexographic printing machine, and the like.
The plurality of color materials to be determined in the determination step may be all color materials used in the target device, or may be some color materials selected from all color materials used in the target device. For example, when C (cyan), M (magenta), Y (yellow), and K (black) color materials are used in the target device, the use amount of the K color material is not used in the determination process. The degree of difference between the current color and the target color may be determined based on the usage amounts of the three primary colors C, M, and Y.

[Aspect 8]
As illustrated in FIGS. 11 and 12, in the determination step ST2, (c) a plurality of settings for the color difference d between the first color patch P1 and the second color patch P2 are prepared, and the determination in the determination step ST1 is performed. The setting according to this may be displayed, and any selection operation from among the plurality of settings may be accepted, and the color difference d between the first color patch P1 and the second color patch P2 may be set to the accepted setting. In the determination step ST2, (d) a plurality of settings for the number N of color patches PA1 included in the color selection color chart CH1 are prepared, and the settings according to the determination in the determination step ST1 are displayed. Any selection operation from the plurality of settings may be accepted, and the number N of color patches PA1 included in the color selection color chart CH1 may be set to the accepted setting.

  When at least one of the components (c) and (d) is performed, the color selection color chart CH1 can be generated with a setting different from the setting according to the determination in the determination step ST1. Therefore, this aspect can provide a technique capable of improving user convenience.

[Aspect 9]
The color selection color chart generation program PR1 exemplified in FIGS. 1 and 4 to 11 selects a color for selecting a color patch PA1 having a color closest to the target color associated with the input data D1 from the plurality of color patches PA1. In order to generate the color chart CH1, the determination function FU1 and the determination function FU2 are realized by a computer. The determination function FU1 includes a current color (for example, a color represented by Expression (7) described later) represented by output data D2 obtained from the input data D1 according to a set profile 520, and the target color (for example, described later). And the degree of difference between the color and the color represented by equation (11). The determination function FU2 determines the color difference d between the first color patch P1 and the second color patch P2 and the number N of color patches PA1 included in the color selection color chart CH1 according to the determination by the determination function FU1. , At least one of them is determined. This aspect can provide a program for generating a color selection color chart in which color patches are arranged efficiently while the number of color patches and the color chart area are limited.

  Furthermore, the present technology records an apparatus for generating a color chart for color selection, a composite apparatus including the apparatus, a control method for these apparatuses, a control program for these apparatuses, a color chart generation program for color selection, and the control program. The present invention can be applied to a computer-readable medium. The aforementioned apparatus may be composed of a plurality of distributed parts.

(2) Specific examples of color management systems:
First, an example of a color management system to which the present technology can be applied will be described with reference to FIG.
A color management system 500 shown in FIG. 1 generates print original data 512 (an example of input data D1) by a print original creation application 501 and converts it into output data D2 by a RIP 502 to form a printed matter 504 on an inkjet printer 503. For example, Adobe (registered trademark) Illustrator (registered trademark) or the like can be used as the print document creation application 501. The ink jet printer 503 uses at least CMYK (cyan, magenta, yellow, and black) ink (coloring material).

Print document data 512 is data representing the process colors CMYK _in for reproducing the color C _t of the CMYK ink in the target printer 580 is an example of color matching of a target device (coloring material) targeted. The target printing machine 580 is an offset printing machine, but may be a gravure printing machine, a flexographic printing machine, or the like. The target color C _t is _expressed by, for example, coordinate values (L _t , a _t , b _t ) of the CIE L ^* a ^* b ^* color space (an example of a device independent color space). The process color CMYK _in corresponds to the amount of CMYK ink used in the target printer 580 and represents the coordinates of the CMYK color space depending on the target printer 580. Print document creation application 501, with reference to the reference profile 511 used for generating the print document data 512 converts the color C _t to process colors CMYK _in. In FIG. 1, the reference profile 511 is expressed as “OffsetProfile”. The reference profile 511 is a file describing the color characteristics of the ink used in the target printing machine 580. For example, a data format called an ICC (International Color Consortium) profile can be used. Specifically, for example, a JapanColor (registered trademark) ICC profile or the like can be used as the reference profile 511.

  Further, the print original creation application 501 may embed the reference profile 511 in the print original data 512. Further, when the color name 531 of the color library is designated, the print original creation application 501 sets the color name 531 in the print original data 512. For example, a Pantone (registered trademark) color library or the like can be used as the color library.

The RIP 502 has a set profile 520 and a color library 532. The profile 520 is set, process colors CMYK _in the L ^* a ^* b ^* color space input profile 521 for converting the color Lab _in, and a color Lab _in the L ^* a ^* b ^* color space There is a printer profile 522 for converting the print color cmyk _p representing the coordinates of the CMYK color space depending on the ink jet printer 503. In FIG. 1, the input profile 521 is expressed as “InputProfile”, and the printer profile 522 is expressed as “PrinterProfile”. For both profiles 521 and 522, for example, the data format of the ICC profile can be used. The printer profile 522 is a file describing the color characteristics of ink used in the ink jet printer 503. In the input profile 521, a reference profile 511 is set in terms of reproducing the color of the target printer 580, but an optional profile 523 different from the reference profile 511 may be set by the user. In FIG. 1, the profile 523 is described as “OptionalProfile”. When the reference profile 511 is embedded in the print document data 512, the RIP 502 may use the reference profile 511 as the set input profile 521.

FIG. 2 schematically illustrates the color gamut R1 indicated by the reference profile 511 and the color gamut R2 indicated by the optional profile 523. In FIG. 2, the horizontal axis represents saturation, the vertical axis represents lightness L ^* , “K100%” represents a black point of 100% black in the color reproduction regions R1 and R2, and “W100%” represents the color reproduction regions R1 and R2. "C100%" indicates the 100% cyan point in the color gamut R1 and R2, and "M100%" indicates the magenta 100% point in the color gamut R1 and R2. Yes. In FIG. 2, the color reproduction region R1 is a region surrounded by a thick line, and the color reproduction region R2 is a region surrounded by a thin line. When the color gamut of the inkjet printer 503 is wider than the color gamut of the target printer 580, as shown in FIG. 2, the color gamut R2 used in the profile 523 rather than the color gamut R1 used in the reference profile 511. Can be widened and printed vividly. For example, when the original color C _t is outside the color gamut R1 but within the color gamut R2 (for example, the point CO1), it is clipped within the color gamut R1 according to the reference profile 511. According to the profile 523, there is no need for a clip. Further, if the original color C _t is outside (eg, point CO2) of the color reproduction gamut R2, the amount of clip is relatively large According to the reference profile 511, the amount of clip is relatively small According to the profile 523. By using such an optional profile 523 as the input profile 521, a color gamut wider than the color gamut of the target printer 580 can be used.

The profile is a color attribute file that defines the correspondence between input colors and output colors. The printer profile changes the color correspondence according to the use conditions such as the printer model, the type of substrate, the observation light source, etc., so the printer profile is different for each printer model, each type of substrate, each observation light source, etc. Prepared for each use condition. In addition, since the color correspondence may change depending on the lot of the color material, the usage period of the printer, etc., the printer profile may be prepared according to these usage conditions. When the printer uses CMYK color materials, for example, color values (L ^* value, a ^* value, and b ^* value) in the L ^* a ^* b ^* color space are defined as input colors, and CMYK as output colors. Values (C value, M value, Y value, and K value) representing the amount of color material used are defined.

The process color CMYK _in of the print original data 512 is converted into the color Lab _{in the} L ^* a ^* b ^* color space according to the input profile 521 and is converted into the print color cmyk _p according to the printer profile 522. When the ink jet printer 503 uses a total of four colors of CMYK inks, the print color cmyk _p is output to the ink jet printer 503 and reproduced on the printed matter 504. When the printer 503 also uses inks such as Lc (light cyan), Lm (light magenta), Dy (dark yellow), Lk (light black), etc., the RIP 502 or the printer 503 separates the print color cmyk _p into dark and light colors. When printing is performed, the printer 503 can reproduce the print color cmyk _p on the printed matter 504. Of course, the printing color itself is not limited to the total of four colors of CMYK.
When the color name 531 is set in the print original data 512, the RIP 502 may convert the color name 531 into the color Lab _{in the} L ^* a ^* b ^* color space with reference to the color library 532. .
In addition to the process color CMYK _in , the RIP 502 is a process color (referred to as CMY _in ) that represents the usage amount of only the three primary colors CMY that are subtractive colors, and the three primary colors R (red) and G (additive colors). It also has an input profile for converting the process color (RGB _in ) representing the intensity of B) and B (blue), etc., and the coordinate values of the L ^* a ^* b ^* color space. Therefore, RIP502 the process colors CMY _in and process colors RGB _in like can also be converted to print color cmyk _p via the L ^* a ^* b ^* color space. In addition, the RIP 502 can also input the color Lab _in the L ^* a ^* b ^* color space and convert it to the print color cmyk _p .

Print color cmyk _p reproduced by the inkjet printer 503 is basically a color that is expected to reproduce the original color C _t. However, the factors such as the following, not to color the printing color cmyk _p expected, it may be necessary to adjust the print color.
(Factor 1) because of the limited color gamut of the target printer 580, the saturation is reduced when converting color C _t to process colors CMYK _in.
A reference profile 511 used during (factor 2) print document data generating an input profile 521 used when converting the process colors CMYK _in the color Lab _in the L ^* a ^* b ^* color space in RIP502, are different.
(Factor 3) The conversion accuracy of the profiles 511 and 520 is not sufficient.
(Factor 4) There is a difference between the color coordinate values L _t , a _t , b _t and the actual color chip color.
(Factor 5) When printing with the inkjet printer 503, it did not match the user's preference.
(Factor 6) Since the inkjet printer 503 also has a limited color gamut, the original color _Ct cannot be reproduced.

Accordingly, the RIP 502 has a function of replacing the print color cmyk _p with a set color (referred to as cmyk _{p ′} ) when a process color CMYK _{in at} a certain point in the color space is input. This replacement is referred to as color replacement 540. The print color cmyk _p before color replacement is the current color represented by the output data D2 obtained from the print document data 512 according to the set profile 520.

(3) Specific examples of color chart for color selection:
FIG. 3 shows, as an example of a color selection color chart for performing color replacement, a printed matter PT1 of a color selection color chart CH1 for selecting a color patch having a color closest to the target color from among a plurality of color patches PA1. Is schematically shown. The patch is also called a color chart. The plurality of color patches PA1 shown in FIG. 3 are arranged vertically and horizontally so that the color difference ΔE in the L ^* a ^* b ^* color space is equal to the printing object M1. The general expression of the color difference ΔE is, for example, ΔE = {(ΔL) ² + (Δa) ² + (ΔL, the difference of the lightness L ^* , the difference of the color coordinate a ^* is Δa, and the difference of the color coordinate b ^* is Δb. Δb) ² } ^1/2

For convenience, identification numbers 11 to 55 are assigned to the patches PA1 shown in FIG. The color selection color chart CH1 formed on the substrate M1 includes a plurality of patches whose colors are gradually changed from the color C _p (see FIG. 1) of the center patch (identification number 33) representing the current color (identification number 33). PA1 is arranged. Each printed matter PT1 shown in FIG. 3 changes the color coordinates a ^* and b ^* representing the hue and saturation at the same lightness. In the schematic example shown in FIG. 3, 5 × 5 (the number of patch intervals from the central patch PA1a) so that the lightness L ^* increases from the lower printed matter toward the upper printed matter by the lightness difference ΔL1 (ΔL1> 0). n = 2 and the number of patches N = (2n + 1) ³ ) are arranged, and for each printed matter PT1, the patch is such that the color coordinate a ^* increases from left to right by the saturation difference Δa1 (Δa1> 0). PA1 is arranged, and the patch PA1 is arranged so that the color coordinate b ^* increases by the saturation difference Δb1 (Δb1> 0) from the bottom to the top. That is, the patches PA1 are arranged at intervals of the color difference ΔL1 for each printed matter, the patches PA1 are arranged at intervals of the color difference Δa1 in the horizontal direction, and the patches PA1 are arranged at intervals of the color difference Δb1 in the vertical direction. In this specific example, d = ΔL1 = Δa1 = Δb1 where d is the color difference between patches, but the present technology also includes a case where ΔL1 = Δa1 = Δb1.

  In this specific example, the first color patch P1 and the second color patch P2 may be adjacent to each other in the plurality of color patches PA1 arranged in the color selection color chart CH1, and are adjacent in the horizontal direction. Alternatively, they may be adjacent in the vertical direction. For example, when the patch PA1 with the identification number 23 is applied to the first color patch P1, the patch PA1 with the identification number 24 on the right is applied to the second color patch P2. If the three patches PA1 that are continuous in the horizontal direction are sequentially designated as the first color patch P1, the second color patch P2, and the third color patch P3, the patch PA1 with the identification number 25 applies to the third color patch P3. In this case, the color difference between the patches P1 and P2 and the color difference between the patches P2 and P3 are the same Δa1. For example, when the patch PA1 having the identification number 52 is applied to the first color patch P1, the patch PA1 having the identification number 42 that is one above is applied to the second color patch P2. Further, if three patches PA1 continuous in the vertical direction are sequentially designated as the first color patch P1, the second color patch P2, and the third color patch P3, the patch PA1 with the identification number 32 is applied to the third color patch P3. In this case, the color difference between the patches P1 and P2 and the color difference between the patches P2 and P3 are the same Δb1.

When the number of color patches in the color selection color chart is fixed, if the color difference d between the color patches is small, the color range of the color selection color chart is narrow and the target color for color replacement is the color selection color chart. The possibility of not falling within the color range of is increased. On the other hand, when the color difference d between the color patches is large, there is a high possibility that the target color for color replacement falls within the color range of the color selection color chart, but when the target color is a color between color patches. It becomes difficult to find a close color. When the user sets the color difference d between the color patches, the judgment is often wrong, and the target color patch cannot be found in the color selection color chart, and the color difference d between the color patches is increased and the color selection color chart is restarted. You will have to print or unnecessarily print many patches.
Therefore, in this specific example, the degree of the color difference (referred to as ΔE _sim ) between the current color and the target color is determined, and the color difference d between the color patches is set according to this determination.

(4) Estimation example of difference between current color and target color:
Next, an example in which the RIP 502 estimates the color difference ΔE _sim between the current color and the target color will be described.
First, a function f _ICC is defined for color conversion using a profile.
(L, a, b) = f _ICC (Profile, A2B, (C, M, Y, K))… (1)
(C, M, Y, K) = f _ICC (Profile, B2A, (L, a, b))… (2)
However, L is L ^* a ^* b ^* lightness color space L ^*, a the L ^* a ^* b ^* color coordinates of a color space a ^*, b are L ^* a ^* b ^* color coordinates of the color space b ^*, C Is the C coordinate in the device-dependent CMYK color space, M is the M coordinate in the device-dependent CMYK color space, Y is the Y coordinate in the device-dependent CMYK color space, and K is the K coordinate in the device-dependent CMYK color space Represents.
The function f _ICC is a function that performs color conversion with reference to the profile. Expression (1) shows an example of converting C, M, Y, and K values into L, a, and b values, and Expression (2) shows L , a, b values are converted into C, M, Y, K values.
The first argument means the profile to be referenced. The second argument indicates the color conversion direction, “A2B” means that C, M, Y, K values are converted to L, a, b values, and “B2A” means L, a, b values are C , M, Y, K value conversion. The third argument means the input color value.

As shown in FIG. 1, the current color C _p represented in the printed material 504 corresponds to the print color cmyk _p represented by the output data D2 when color replacement is not performed. The coordinate values (L in — _p , a in — _p , b in — _p ) of the L ^* a ^* b ^* color space corresponding to the current color C _p can be obtained from Equation (1) as follows.
(L _{in_p} , a _{in_p} , b _{in_p} ) = f _ICC (PrinterProfile, A2B, cmyk _p )… (3)
Here, the first argument “PrinterProfile” means that color conversion is performed with reference to the printer profile 522.

The print color cmyk _p is a color resulting from color conversion of the process color CMYK _in represented by the print document data 512 using the setting profile 520. The L, a, b values (L _in , a _in , b _in ) obtained from the process color CMYK _in according to the input profile 521 can be obtained from the equation (1) as follows.
(L _in , a _in , b _in ) = f _ICC (InputProfile, A2B, CMYK _in )… (4)
Here, the first argument “InputProfile” means that color conversion is performed with reference to the input profile 521.

Further, the print color cmyk _p obtained from the L, a, b values (L _in , a _in , b _in ) according to the printer profile 522 can be obtained from the equation (2) as follows.
cmyk _p = f _ICC (PrinterProfile, B2A, (L _in , a _in , b _in ))… (5)
Substituting equation (4) into equation (5) yields the following equation:
cmyk _p = f _ICC (PrinterProfile, B2A, f _ICC (InputProfile, A2B, CMYK _in ))… (6)

従って、現在色Ｃ_pのL,a,b値は、プロセスカラーＣＭＹＫ_inから式(7)により求めることができる。 From the above, when equation (6) is substituted into equation (3), the following equation is obtained.

Therefore, the L, a, and b values of the current color C _p can be obtained from the process color CMYK _in by equation (7).

ここで、第一引数の「OptionalProfile」は、プロファイル５２３を参照して色変換を行うことを意味している。
また、この場合の目標色ｃｍｙｋ_{t_p}に対応するＬ^*ａ^*ｂ^*色空間の座標値(L_{t_p},a_{t_p},b_{t_p})は、以下の式で表される。
(L_{t_p},a_{t_p},b_{t_p})＝ｆ_ICC(PrinterProfile,A2B,cmyk_{t_p}) …(9) Here, it is assumed that the current color C _p is not an expected color due to the factors 1 to 6 described above. As an example, it is assumed that print document data 512 is generated according to the reference profile 511, and a profile 523 that is vividly printed using a wide color gamut is set as the input profile 521. In this case, when the color reproduced by the target printing machine 580 is targeted, the color is reproduced more vividly than the target color and deviates. _Assuming that the print color at this time is cmyk _{v_p} , the coordinate values (L _{v_p} , a _{v_p} , b _{v_p} ) of the L ^* a ^* b ^* color space corresponding to the print color cmyk _{v_p} can be expressed by the following equations.

Here, “OptionalProfile” as the first argument means that color conversion is performed with reference to the profile 523.
In this case, the coordinate values (L _{t_p} , a _{t_p} , b _{t_p} ) of the L ^* a ^* b ^* color space corresponding to the target color cmyk _{t_p} are expressed by the following equations.
(L _{t_p} , a _{t_p} , b _{t_p} ) = f _ICC (PrinterProfile, A2B, cmyk _{t_p} ) (9)

The target color cmyk _{t_p} is obtained by converting the process color CMYK _in represented by the print document data 512 according to the reference profile 511 and further according to the printer profile 522.
cmyk _{t_p} = f _ICC (PrinterProfile, B2A, f _ICC (OffsetProfile, A2B, CMYK _in ))… (10)
Here, the first argument “OffsetProfile” means that color conversion is performed with reference to the reference profile 511.

従って、目標色ｃｍｙｋ_{t_p}のL,a,b値は、プロセスカラーＣＭＹＫ_inから式(11)により推定することができる。 From the above, when equation (10) is substituted into equation (9), the following equation is obtained.

Therefore, the L, a, and b values of the target color cmyk _{t_p} can be estimated from the process color CMYK _in by the equation (11).

Here, of the estimated color difference ΔE _sim between the current color and the target color, the L ^* component is ΔL _sim , the a ^* component is Δa _sim , and the b ^* component is Δb _sim . The color difference components ΔL _sim , Δa _sim , and Δb _sim are L, a, b values (L in — _p , a in — _p , b in — _p ) of the current color in Equation (7) and L, a, b in the target color of Equation (11). Using the values (L _{t — p} , a _{t — p} , b _{t — p} ), the following equation can be used.
ΔL _sim = | L _{t_p} −L _{in_p} | (12)
Δa _sim = | a _{t_p} −a _{in_p} | (13)
Δb _sim = | b _{t_p} −b _{in_p} | (14)

Therefore, when the color difference d between the color patches is set so that the color patch of the target color is included in the color range of the color selection color chart CH1 using the color difference components ΔL _sim , Δa _sim , and Δb _sim , the target is efficiently obtained. A color patch of a color can be selected.

(5) Specific examples of the color adjusting device:
FIG. 4 schematically shows an example of the configuration of a color adjustment apparatus that implements the color selection color chart generation method. 4 includes a central processing unit (CPU) 111, a read only memory (ROM) 112, a random access memory (RAM) 113, a storage device 114, a display device 115, an input device 116, and a communication I / F. (Interface) 118, etc. are connected so that information can be input and output with each other. The storage device 114 stores a color adjustment program PR0, profiles 511, 522, 523, and the like. As the storage device 114, a non-volatile semiconductor memory such as a flash memory, a magnetic storage device such as a hard disk, or the like can be used. A liquid crystal display panel or the like can be used for the display device 115. As the input device 116, a pointing device, a hard key including a keyboard, a touch panel attached to the surface of the display panel, or the like can be used. The communication I / F 118 is connected to the communication I / F 210 of the printer 503 and inputs / outputs information to / from the printer 503. USB (Universal Serial Bus), near field communication standard, etc. can be used for the standard of communication I / F 118,210. Communication of the communication I / Fs 118 and 210 may be wired, wireless, or network communication such as a LAN (Local Area Network) or the Internet.

The color adjustment apparatus 100 includes a computer such as a personal computer (including a tablet terminal). The color adjustment apparatus 100 may have all the constituent elements 111 to 118 in one housing, but may be composed of a plurality of apparatuses that are divided so as to communicate with each other. Further, the present technology can be implemented even if the printer is in the color adjustment apparatus 100, and the printer itself having a printing function may perform the color adjustment processing of the present technology.
The printer 503 obtains print data based on the output image generated by the color adjustment apparatus 100, and forms a print image corresponding to the output image on the printing material based on the print data. In addition to inkjet printers, the printer 503 includes electrophotographic printers such as laser printers, and also includes copiers, facsimiles, and multifunction machines having these functions.

  The color adjustment program PR0 shown in FIG. 4 includes a color selection color chart generation program PR1 that causes the color adjustment apparatus 100 to realize the determination function FU1 and the determination function FU2.

(6) Specific example of color adjustment processing:
FIG. 5 shows an example of color adjustment processing performed by the color adjustment apparatus 100 shown in FIG. In this example, the color difference determination process between patches in step S120 is performed by the color selection color chart generation program PR1. Hereinafter, the description of “step” is omitted.

When the process is started, the color adjustment apparatus 100 receives an input for specifying the current color to be replaced (S110). The process of S110 can be, for example, a process of acquiring information representing the current color according to the operation when the user operates the input device 116, and from among a plurality of colors displayed on the display device 115. A process for accepting an operation for selecting one color, a process for accepting an operation for inputting L, a, and b values can be performed. In the color management system 500 shown in FIG. 1, the print color cmyk _p before color replacement is the current color C _p , and the print color cmyk _p has L, a, b values (L in — _p , a in — _p , b in — _p ), and Process color CMYK _in is supported. The information representing the current color may be any of output data D2 representing the print color cmyk _p , L, a, b values (L in — _p , a in — _p , b in — _p ), and input data D1 representing the process color CMYK _in .

  After the process of S110, the color adjustment apparatus 100 performs a color difference determination process between patches for determining the color difference d between the color patches (S120). The process of S120 will be described later.

After the processing of S120, the color adjustment apparatus 100 determines the color chart for color selection CH1 (see FIG. 5) based on the color difference d = ΔL1 = Δa1 = Δb1 between the color patches and the patch interval number n = 4 from the central patch PA1a. 3) is printed by the printer 503 (S130). Here, the color adjusting apparatus 100 determines the lightness L ^* by the lightness difference ΔL1 for the N = (2n + 1) ³ color patches PA1 with the color patch _PA1a of the current color (L _{in_p} , a _{in_p} , b _{in_p} ) as the center. The color coordinate a ^* is increased or decreased by a saturation difference Δa1, and the color coordinate b ^* is increased or decreased by a saturation difference Δb1. As a result, a printed material PT1 of the color selection color chart CH1 in which N color patches PA1 are printed on the printing material M1 is obtained.

  Thereafter, although not essential to the present technology, the process is branched depending on whether or not the condition is changed and the color selection color chart CH1 is reprinted (S140). This branching process can be, for example, a process of displaying a reprint button and a color selection button on the display device 115 and branching the process according to the button operation. In this case, when the operation of the reprint button is accepted by the input device 116, the color adjustment apparatus 100 changes the condition and returns the process to S130, and when the operation of the color selection button is accepted by the input device 116, the process proceeds to S150. The change of the condition includes a change of the color difference d between the color patches, a change of the number N of patches, and the like.

When reprinting is not performed, the color adjustment apparatus 100 accepts selection of the color patch closest to the target color cmyk _{t_p} from among the plurality of color patches PA1 included in the color selection color chart CH1, and _performs color replacement 540. (S150), the color adjustment process is terminated. The color patch selection processing includes, for example, processing for accepting an operation input of an identification number associated with each patch PA1 in the input device 116, and displaying a display patch corresponding to each patch PA1 on the display device 115 to display a plurality of display patches. For example, the input device 116 may accept an operation for selecting one display patch from among the processes. In addition, the color adjusting apparatus 100 converts the process color CMYK _in directly into the target color cmyk _{t_p} when the print original data 512 representing the process color CMYK _in corresponding to the print color cmyk _p before color replacement is input to the _{RIP 502.} Set to

(7) Specific example of color difference determination process between patches:
Next, an example in which at least one of the color difference d between the color patches and the number of patches N = (2n + 1) ³ is determined in the inter-patch color difference determination process performed in S120 of FIG. As an easy-to-understand example, the color difference d is determined by fixing the patch interval number n from the center to 4 and switching the color difference between color patches d = ΔL1 = Δa1 = Δb1 between 1.0 and 2.0. The algorithm will be described. FIG. 6 shows an example of the inter-patch color difference determination process including this algorithm. In this example, S210 to S240 correspond to the determination step ST1 and the determination function FU1, and S250 and S260 correspond to the determination step ST2 and the determination function FU2.

When the processing is started, the color adjustment apparatus 100 determines whether or not the input data D1 designates a device color (for example, cmykin _in or cmy _in ) including at least CMY (S210). When the input data D1 specifies a device color other than at least CMY, such as L ^* a ^* b ^* or RGB, the color reproduction range of the input device is relatively wide and sufficient for the color reproduction range of the special color ink Has a wide color gamut. Therefore, the saturation decreases hardly occurs when the color C _t was converted into L ^* a ^* b ^* and RGB in the print document generating application 501, the difference between the original color C _t and the print color cmyk _p does not increase. Therefore, even if the inter-patch color difference d is set to 1.0 which is the smaller one, the probability that the target color cmyk _{t_p} falls within the color range of the color selection color chart CH1 is high. The resolution of the selection color chart CH1 is also increased. Therefore, when the input data D1 specifies L ^* a ^* b ^* , RGB, or the like, the color adjustment apparatus 100 advances the process to S250, determines the inter-patch color difference d to 1.0, and determines the inter-patch color difference. The decision process is terminated.

When the input data D1 specifies a device color including at least CMY, since the color reproduction range of the input device is relatively narrow, the color C _{t is changed} to a device color (for example, cmyk _in or cmy _in ) by the print document creation application 501. There is a possibility that the saturation is relatively lowered when converted. If the saturation drops greatly during this conversion, the difference between the original color C _t and the print color cmyk _p increases, and when the inter-patch color difference d is set to 1.0 which is the smaller one, the target color cmyk _{t_p} is the color chart for color selection. The probability of going out of the color range of CH1 increases. Therefore, in the process of S210, the degree of difference between the current color and the target color is determined.

Referring to FIG. 2, is clipped to the gamut R1 when converted into the device color if there is original color C _t outside the color gamut R1 shown in the reference profile 511, the saturation is reduced. Therefore, the device color CMYK _{in at} or near the boundary of the color gamut R1 is likely to have a relatively large reduction in saturation. For example, in the device color CMYK _in , the amount of C is 0% (minimum value) or 100% (maximum value), the amount of M is 0% or 100%, or the amount of Y is 0% or 100 If it is in%, there is a high possibility that the saturation is reduced when the print document data is generated. On the other hand, a sufficiently inner portion in the color reproduction range R1 is unlikely to have a reduced saturation when generating print document data. Therefore, the color adjustment apparatus 100 determines the possibility of saturation reduction during print document data generation based on the device color CMYK _in representing the usage amounts of a plurality of inks used in the target printing machine (S220). This determination process also determines the degree of difference between the current color and the target color.

FIG. 7 schematically illustrates an example of a determination criterion for determining the possibility of a decrease in saturation when generating print document data. Here, the amount of C is simply expressed as C (0% ≦ C ≦ 100%), the amount of M is simply expressed as M (0% ≦ M ≦ 100%), and the amount of Y is simply expressed as Y (0% ≦ Y ≦ Y). ≦ 100%).
As described above, in the device color CMYK _in ,
(Criteria 1) C = 0%, C = 100%, M = 0%, M = 100%, Y = 0%, or Y = 100%
If this is the case, there is a high possibility that the saturation is reduced when the print document data is generated. In these cases, the color saturation d between patches is determined to be 2.0, which is larger, assuming that the saturation reduction at the time of generating the print document data is large.

The threshold for the amount of C is TLc, THc (0% <TLc <50% <THc <100%), and the threshold for the amount of M is TLm, THm (0% <TLm <50% <THm <100%). And the threshold for the amount of Y is TLy, THy (0% <TLy <50% <THy <100%).
(Criteria 2) TLc ≦ C ≦ THc, TLm ≦ M ≦ THm, and TLy ≦ Y ≦ THy
If it is, the device color CMYK _in is sufficiently inner portion in the color reproduction range R1, to be determined but are likely desaturation is small at the time of printing document data generating. In this case, it is determined whether the inter-patch color difference d is set to 1.0 or 2.0 in the processing of S230 to S240 described later. The color difference d is expressed as “provisionally determined” to 1.0 which is smaller. The lower thresholds TLc, TLm, and TLy may be about 0 to 10%. The upper thresholds THc, THm, THy may be about 90 to 100%.
It should be noted that a range that does not meet both the determination criteria 1 and 2 includes a boundary between the case where the inter-patch color difference d = 2.0 is determined and the case where the inter-patch color difference d = 1.0 is temporarily determined. .

When the condition for determining the inter-patch color difference d to 2.0 is satisfied, such as the determination criterion 1 is satisfied, the color adjusting apparatus 100 proceeds to S260, determines the inter-patch color difference d to 2.0, and determines the inter-patch color difference d. The color difference determination process is terminated.
The determination criteria 1 and 2 can be changed as appropriate. For example, Y is excluded from the determination criteria 1 and 2, the determination criterion 1 is “C = 0%, C = 100%, M = 0%, or M = 100%”, and the determination criterion 2 is “TLc ≦ C ≦ THc and TLm ≦ M ≦ THm ”. Alternatively, Y = 100% may be excluded from the criterion 1 while leaving Y = 0%.

On the other hand, if the condition for temporarily determining the inter-patch color difference d to 1.0, such as the criteria 2 is met is met, the color adjustment device 100 estimates the target color cmyk _{t_p,} target color cmyk _{t_p} the current color and the estimated Differences ΔL _sim , Δa _sim , Δb _sim from (print color cmyk _p that has not undergone color replacement) are obtained (S230). As described above, L for the current color C _p, a, b values _L in_p, a in_p, b in_p can be obtained from process colors CMYK _in simulating the equation (7). _Further, the L, a, and b values (L _{t_p} , a _{t_p} , b _{t_p} ) of the target color cmyk _{t_p} can be simulated from the process color CMYK _in by the equation (11). From these L, a, and b values, ΔL _sim = | L _t — _p −L in _—p | (Expression (12)), Δa _sim = | a _{t —p} −a _{in_p} | (Expression (13)), and Δb _sim = | b _t — _p −b in — _p | (Expression (14)) can be estimated.

Further, the differences ΔL _sim , Δa _sim , Δb _sim between the current color and the target color may be estimated by a simple method described below.
As described above, the L, a, b values (L _in , a _in , b _in ) obtained from the process color CMYK _in are (L _in , a _in , b _in ) = f _ICC (InputProfile, A2B, CMYK _in ) (Equation (4)). L, a, b values (L _in , a _in , b _in ) are examples of first coordinate values.
Further, according to the reference profile 511 used for generating the print document data 512, the L, a, b values (L _m , a _m , b _m ) obtained from the process color CMYK _in can be obtained as follows. it can.
(L _m , a _m , b _m ) = f _ICC (OffsetProfile, A2B, CMYK _in )… (15)
L, a, b values (L _m , a _m , b _m ) are examples of second coordinate values.

The color difference components ΔL _sim , Δa _sim , and Δb _sim are the L, a, b values (L _in , a _in , b _in ) of the equation (4) corresponding to the current color and the equation (15) corresponding to the target color. Using the L, a, b value (L _m , a _m , b _m ), it can be obtained by the following equation.
ΔL _sim = | L _m −L _in | (16)
Δa _sim = | a _m −a _in ｜… (17)
Δb _sim = | b _m −b _in | (18)

After the process of S230, the color adjusting apparatus 100 branches the process based on the differences ΔL _sim , Δa _sim , Δb _sim between the current color and the target color (S240). This determination is based on whether or not the target color is included in the color range of the color selection color chart CH1. In the example shown in FIG. 6, the maximum value Max (ΔL _sim , Δa _sim , Δb _sim ) of the color difference components ΔL _sim , Δa _sim , Δb _sim and the color range (d × n = 1.0 × 4).
When the value Max (ΔL _sim , Δa _sim , Δb _sim ) is less than 1.0 × 4, there is a relatively high possibility that the target color is included in the color range of the color selection color chart CH1. In this case, the color adjustment apparatus 100 determines the inter-patch color difference d to be the smaller 1.0 (S250), and ends the inter-patch color difference determination process.
When the value Max (ΔL _sim , Δa _sim , Δb _sim ) is 1.0 × 4 or more, there is a relatively high possibility that the target color does not fall within the color range of the color selection color chart CH1. In this case, the color adjustment apparatus 100 determines the inter-patch color difference d to be the larger 2.0 (S260), and ends the inter-patch color difference determination process.
Therefore, the determination process in S240 determines the degree of difference between the current color and the target color.

After that, in S130 of FIG. 5, the color selection color chart CH1 having the color patch PA1 of the number N of patches with the inter-patch color difference d = (2n + 1) ³ is printed. The color range (d × n) of the color selection color chart CH1 is a range according to the degree of difference between the current color and the target color. Therefore, in this specific example, the inter-patch color difference d and the patch number N can be appropriately set automatically while the number of color patches and the color chart area are limited, and the number of print patches and the number of prints can be reduced. Color adjustment time and printing cost can be reduced.

In the determination process of S240, it may be determined whether or not the value Max (ΔL _sim , Δa _sim , Δb _sim ) is 1.0 × 4 or less.
Also, the current color due to the above-mentioned factor 3 (accuracy of profile conversion is not sufficient) or factor 4 (the color coordinate values L _t , a _t , b _t are different from the actual color chip color). Assuming that there is a difference between the target color and the target color, the error Ec (0 <Ec <d) may be considered. In this case, in S240, the value {Max (ΔL _sim , Δa _sim , Δb _sim ) + Ec} is compared with 1.0 × 4. For example, when the color difference is less than 1.0 × 4, the inter-patch color difference d is set to 1. The color difference d between patches may be determined to be 2.0 when it is 1.0 × 4 or more.

Further, the inter-patch color difference d is not limited to 1.0 and 2.0, but can be various values. Setting the color difference d between patches to two types is merely an example, and may be set to three or more types.
Furthermore, instead of performing the process of S240, the inter-patch color difference d may be calculated based on the differences ΔL _sim , Δa _sim , Δb _sim between the current color and the target color. For example, the color adjusting apparatus 100 may determine the inter-patch color difference d as Max (ΔL _sim , Δa _sim , Δb _sim ) / 4 or {Max (ΔL _sim , Δa _sim , Δb _sim ) + Ec} / 4. Good.

Furthermore, instead of changing the inter-patch color difference d, the number of patches N = (2n + 1) ³ may be changed. For example, the inter-patch color difference d is fixed to 1.0, and the patch interval number n from the center is changed to 4 or 8 as shown in parentheses in FIG. 4 may be determined, and the patch interval number n may be determined to be 8 in S260. Since the patch number N is determined when the patch interval number n is determined, determining the patch interval number n is included in determining the patch number N.
Of course, the patch interval number n is not limited to 4 and 8, and can be various. Setting the number of patch intervals n to two types is merely an example, and three or more types may be set.
Further, the patch interval number n may be calculated based on the differences ΔL _sim , Δa _sim , Δb _sim between the current color and the target color.
Furthermore, it is possible to change both the inter-patch color difference d and the patch interval number n. For example, d = 1.0 and n = 4 may be determined in S250, and d = 1.5 and n = 6 may be determined in S260.

Note that without performing the processing of S220～S240, in S210, it performs the processing when the S260 the input data D1 designates at least includes device color of CMY (e.g. cmyk _in) (e.g., d = 2.0), When the condition is not satisfied, the process of S250 (for example, d = 1.0) may be performed.
Further, the processing of S210, S230 to S240 is not performed, and in S220, the criterion 1 (for example, C = 0%, C = 100%, M = 0%, M = 100%, Y = 0%, or Y If the condition for determining the inter-patch color difference d to 2.0 is satisfied, for example, when the condition is not satisfied, the process of S260 is performed (for example, d = 2.0), and the process of S250 is performed when the condition is not satisfied (for example, d = 1.0). ) May be performed.
Further, the processing of S210 to S220 is not performed, and in S240, when Max (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 4, the processing of S250 (for example, d = 1.0) is performed, and the condition When not established, the process of S260 (for example, d = 2.0) may be performed.

(8) Modification:
Various modifications can be considered for the present invention.
For example, the color difference described above may be a color difference based on the color difference formulas CIEDE2000, CMC, CIDEDE94, and the like.
The printer 503 may use color materials other than the colors described above, or may not use some color materials of CMYK.

FIG. 8 shows an example of the inter-patch color difference determination process for determining the degree of difference between the current color and the target color by a simpler method. In FIG. 8, the processing of S230 to S240 shown in FIG. 6 is replaced with the processing of S310.
In S220, if the condition for temporarily determining the inter-patch color difference d to 1.0 is satisfied, such as the determination criterion 2 (TLc ≦ C ≦ THc, TLm ≦ M ≦ THm, and TLy ≦ Y ≦ THy) is satisfied, The color adjustment apparatus 100 determines whether the set input profile 521 is the reference profile 511 (S310).

When the input profile 521 is the reference profile 511, there is a high possibility that the reference profile 511 is used to generate the print document data 512. In this case, the color adjustment apparatus 100 determines the inter-patch color difference d to be the smaller 1.0 (S250), and ends the inter-patch color difference determination process.
When the input profile 521 is not the reference profile 511 such as the profile 523, there is a high possibility that the color gamut indicated by the input profile 521 is different from the color gamut R1 indicated by the reference profile 511. In this case, the color adjustment apparatus 100 determines the inter-patch color difference d to be the larger 2.0 (S260), and ends the inter-patch color difference determination process.
Therefore, the determination process in S310 determines the degree of difference between the current color and the target color.

  As described above, as described in (a) of [Aspect 6], when the input profile 521 is not the reference profile 511, the inter-patch color difference d = 1.0 when the input profile 521 is the reference profile 511. The color difference between patches d = 2.0 is larger.

In the example shown in FIG. 8, the number of patches N = (2n + 1) ³ may be changed instead of changing the color difference d between patches. For example, the color difference d between patches is fixed to 1.0, and the patch interval number n from the center is changed to 4 or 8 as shown in parentheses in FIG. 4 may be determined, and the patch interval number n may be determined to be 8 in S260. In this case, as described in (b) of [Aspect 6], when the input profile 521 is not the reference profile 511, the number of patches N = 9 × 9 × 9 when the input profile 521 is the reference profile 511. The number of patches N = 17 × 17 × 17 is larger.
Of course, it is possible to change both the color difference d between patches and the number n of patch intervals.

FIG. 9 shows an example of the inter-patch color difference determination process in which three types of inter-patch color difference d settings are prepared. For the convenience of illustration, S210 to S220 shown in FIG. 6 are omitted. The same applies to FIGS. 10 and 11 described later. In FIG. 9, the process of S320-S328 is performed after the process of S230. As shown in S324 to S328, the inter-patch color difference d is set to 1.0, 1.5, and 2.0.
After the color difference components ΔL _sim , Δa _sim , and Δb _sim are obtained in S230, the color adjusting apparatus 100 first compares the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) with 1.5 × 4. The process is branched (S320). For example, when MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.5 × 4, the color adjustment apparatus 100 sets the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) and 1.0 × 4. The processing is branched in comparison (S322). For example, when MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 4, the color adjustment apparatus 100 determines the inter-patch color difference d to 1.0 (S324), and the inter-patch color difference determination process End. When 1.0 × 4 ≦ MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.5 × 4, the color adjustment apparatus 100 determines the inter-patch color difference d to 1.5 (S326), and the patch The inter-color difference determination process is terminated. When 1.5 × 4 ≦ MAX (ΔL _sim , Δa _sim , Δb _sim ), the color adjustment apparatus 100 determines the inter-patch color difference d to 2.0 (S 328), and ends the inter-patch color difference determination process. Let

If MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 4, two types of settings of d = 1.0 and d = 1.5 remain in the determination processing in S320. In this case, the inter-patch color difference d is determined by the determination processing in S322 so that d = 1.0 is relatively small. As described above, when there are a plurality of settings according to the determination of S320 in the determination step ST1, the inter-patch color difference d is determined so that the setting having the smallest color difference among the plurality of settings is obtained. As a result, the color patch for target color is included in the generated color chart for color selection CH1, while the color difference d between patches is suppressed from becoming too large.

FIG. 10 shows an example of patch interval number determination processing in which three types of settings of the patch interval number n (patch number N) from the center are prepared. For the convenience of illustration, S210 to S220 shown in FIG. 6 are omitted. In FIG. 10, the process of S330-S338 is performed after the process of S230. As shown in S334 to S338, there are 4, 6, and 8 for setting the patch interval number n.
After the process of S230, the color adjusting apparatus 100 first branches the process by comparing the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) with 1.0 × 6 (S330). For example, when MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 6, the color adjustment apparatus 100 sets the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) and 1.0 × 4. The processing is branched in comparison (S332). For example, when MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 4, the color adjustment apparatus 100 determines the patch interval number n to be 4 (S334), and ends the inter-patch color difference determination processing. Let When 1.0 × 4 ≦ MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 6, the color adjustment apparatus 100 determines the patch interval number n to be 6 (S336), and the color difference between patches The decision process is terminated. When 1.0 × 6 ≦ MAX (ΔL _sim , Δa _sim , Δb _sim ), the color adjustment apparatus 100 determines the patch interval number n as 8 (S 338), and ends the patch interval number determination process.

When MAX (ΔL _sim , Δa _sim , Δb _sim ) <1.0 × 4, two types of settings of n = 4 and n = 6 remain in the determination processing in S330. In this case, the patch interval number n is determined by the determination processing in S332 so that n = 4 is relatively small. As described above, when there are a plurality of settings according to the determination of S330 in the determination step ST1, the patch interval number n, that is, the number of patches N = (2n + 1) is set so that the number of the settings among the plurality of settings is the smallest. ³ is determined. As a result, the generated color selection color chart CH1 includes the color patches of the target color, while suppressing the number N of patches from becoming too large.

By the way, the inter-patch color difference d and the number N of patches may not be set completely automatically, but may be displayed on a user interface having options.
FIG. 11 shows an example of the inter-patch color difference determination process that accepts the selection of the inter-patch color difference d. In FIG. 11, the process of S340-S344 is performed after the process of S230. FIG. 12A schematically illustrates a color difference selection screen 610 between patches displayed on the display device 115 as an example of (c) of [Aspect 8]. In this example, three types of patch color difference d are prepared: 1.0, 1.5, and 2.0.

After the process of S230, the color adjusting apparatus 100 first determines a recommended inter-patch color difference based on the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) (S340). For example, the recommended inter-patch color difference can be determined by performing the same determination process as in S320 to S322 of FIG. Next, the color adjustment apparatus 100 displays the inter-patch color difference selection screen 610 shown in FIG. 12A on the display device 115 (S342). Here, the color adjustment apparatus 100 displays all the settings of the inter-patch color difference d on the inter-patch color difference selection screen 610 in a selectable manner, and recommends the recommended inter-patch color difference according to the determination in S342 in the determination step ST1 (FIG. 12A displays 1.5) as an initial setting. Thereafter, the color adjustment apparatus 100 accepts any selection operation from all the settings of the inter-patch color difference d, finally determines the inter-patch color difference d to the accepted setting (S344), and performs the inter-patch color difference determination process. Terminate. Here, when the user operates the enter button 612 without operating the option 611, the color adjustment apparatus 100 sets the inter-patch color difference d to the recommended inter-patch color difference as initially set. When the user operates the option 611 and operates the determination button 612, the color adjustment apparatus 100 sets the inter-patch color difference d to the operated inter-patch color difference.
As described above, the color selection color chart CH1 can be generated with a setting different from the recommended color difference between patches. Therefore, this example can improve user convenience.

Further, as shown in parentheses in FIG. 11, the number of patches N = (2n + 1) ³ may be changed instead of changing the color difference d between patches. FIG. 12B schematically illustrates a patch number selection screen 620 displayed on the display device 115 as an example of (d) of [Aspect 8]. In this example, the number of patches N is set to 9 × 9 × 9 (n = 4), 13 × 13 × 13 (n = 6), and 17 × 17 × 17 (n = 8). Yes.

After the process of S230, the color adjustment apparatus 100 first determines the recommended number of patches based on the maximum value MAX (ΔL _sim , Δa _sim , Δb _sim ) (S340). For example, the recommended number of patches can be determined by performing a determination process similar to S330 to S332 in FIG. Next, the color adjustment apparatus 100 displays the patch number selection screen 620 shown in FIG. 12B on the display device 115 (S342). Here, the color adjustment apparatus 100 displays all the settings of the number of patches N on the inter-patch color difference selection screen 610 in a selectable manner, and recommends the number of patches according to the determination of S342 in the determination step ST1 (in FIG. 12B). 13 × 13 × 13) is displayed as the default setting. Thereafter, the color adjustment apparatus 100 accepts any selection operation from all the settings of the patch number N, finally determines the patch interval number n from the center as the accepted setting (S344), and determines the patch interval number. End the process. Here, when the user operates the enter button 622 without operating the option 621, the color adjustment apparatus 100 sets the patch interval number n to the recommended patch interval number (n = 6 in FIG. 12B) as initially set. When the user operates the selection button 622 by operating the option 621, the color adjustment apparatus 100 sets the patch interval number n to the operated patch interval number.
As described above, the color selection color chart CH1 can be generated with a setting different from the recommended number of patches. Therefore, this example can improve user convenience.

(9) Conclusion:
As described above, according to the present invention, there are provided various techniques for generating a color selection color chart in which color patches are efficiently arranged in a limited number of color patches and a color chart area. Can do. Needless to say, the above-described basic functions and effects can be obtained even with a technique that includes only the constituent elements according to the independent claims.
In addition, the configurations disclosed in the above-described examples are mutually replaced or the combination is changed, the known technology and the configurations disclosed in the above-described examples are mutually replaced or the combinations are changed. The configuration described above can also be implemented. The present invention includes these configurations and the like.

DESCRIPTION OF SYMBOLS 100 ... Color adjustment apparatus, 114 ... Memory | storage device, 115 ... Display apparatus, 116 ... Input device, 500 ... Color management system, 501 ... Print original creation application, 502 ... RIP, 503 ... Printer, 504 ... Printed matter, 511 ... Reference | standard profile 512 ... Print original data, 520 ... Set profile, 521 ... Input profile, 522 ... Printer profile, 523 ... Profile, 540 ... Color replacement, 580 ... Target printer (example of target device), 610 ... Color difference between patches Selection screen, 620 ... patch number selection screen, D1 ... input data, D2 ... output data, CH1 ... color chart for color selection, FU1 ... judgment function, FU2 ... decision function, M1 ... substrate, P1 ... first color patch, P2 ... second color patch, P3 ... third color PA1,... Patch, PA1a ... center patch, PR0 ... color adjustment program, PR1 ... color chart generation program for color selection, PT1 ... printed matter, R1, R2 ... color reproduction area, ST1 ... determination step, ST2 ... determination step .

Claims (9)

A color selection color chart generation method for generating a color selection color chart for selecting a color patch of a color closest to a target color to be associated with input data from a plurality of color patches,
The plurality of color patches include a first color patch and a second color patch adjacent to each other,
A determination step of determining the degree of difference between the current color represented by the output data obtained from the input data according to the set profile and the target color;
A determination step of determining at least one of a color difference between the first color patch and the second color patch and the number of color patches included in the color selection color chart according to the determination by the determination step;
A color chart generation method for color selection, including:   In the determining step, a difference between the current color and the target color is estimated, and based on the estimated difference, the current color is included in the color range of the color selection color chart. The method for generating a color chart for color selection according to claim 1, wherein the degree of difference between the color and the target color is determined.   In the determination step, a plurality of color difference settings between the first color patch and the second color patch are prepared, and when there are a plurality of settings according to the determination by the determination step among these settings, the plurality of settings The color selection color chart generation method according to claim 2, wherein the color difference between the first color patch and the second color patch is determined so that the color difference having the smallest color difference is set.   In the determination step, a plurality of settings for the number of color patches included in the color chart for color selection are prepared, and when there are a plurality of settings according to the determination by the determination step among these settings, The color selection color chart generation method according to claim 2 or 3, wherein the number of color patches included in the color selection color chart is determined so that the number of settings is the smallest.   In the determining step, a first coordinate value of a device independent color space is obtained from the input data according to the set profile, and a first value of the device independent color space is obtained from the input data according to a reference profile used for generating the input data. The two coordinate values are obtained, and the degree of the difference between the current color and the target color is determined based on the difference between the first coordinate value and the second coordinate value. The method for generating a color chart for color selection according to the item. In the determination step, it is determined whether or not an input profile included in the set profile is a reference profile used for generating the input data,
In the determination step,
(A) The first color patch and the second color when the input profile is not the reference profile than the color difference between the first color patch and the second color patch when the input profile is the reference profile. To increase the color difference from the color patch,
(B) Colors included in the color selection color chart when the input profile is not the reference profile, rather than the number of color patches included in the color selection color chart when the input profile is the reference profile Increasing the number of patches,
The color chart generation method for color selection as described in any one of Claims 1-5 which performs at least one of these. The input data includes data representing usage amounts of a plurality of color materials used in the target device,
The degree of difference between the current color and the target color is determined in the determination step based on usage amounts of a plurality of color materials represented by the input data. The method for generating a color chart for color selection according to the item. In the determination step,
(C) preparing a plurality of color difference settings between the first color patch and the second color patch, displaying settings according to the determination by the determination step, and selecting any one of the plurality of settings Receiving an operation, and setting the received color difference between the first color patch and the second color patch;
(D) preparing a plurality of settings for the number of color patches included in the color selection color chart, displaying settings according to the determination in the determination step, and selecting any one of the plurality of settings And setting the received number of color patches included in the color selection color chart,
The color chart generation method for color selection as described in any one of Claims 1-7 which performs at least one of these. A color selection color chart generation program for generating a color selection color chart for selecting a color patch of a color closest to a target color associated with input data from a plurality of color patches,
The plurality of color patches include a first color patch and a second color patch adjacent to each other,
A determination function for determining the degree of difference between the current color represented by the output data obtained from the input data according to a set profile and the target color;
A determination function for determining at least one of a color difference between the first color patch and the second color patch and the number of color patches included in the color selection color chart according to the determination by the determination function;
A color chart generation program for color selection, which makes a computer realize.

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