JP2008182651A - Color mixture simulation apparatus, color mixture simulation method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color mixture simulation apparatus which can exhibit a sufficient performance for performing an interactive processing while maintaining the precision of color reproduction, and simulates the color mixture of ink. <P>SOLUTION: While referring to a colorimetric information database 21, a color difference between inputted first-order color information and a first-order color of colorimetric information is calculated and colorimetric information with a minimum sum of color differences is extracted as most approximate information. Next, while assuming the Lambert-Beer law, second-order, third-order color information is estimated from the first-order color information. Interpolation arithmetic is then performed on the most approximate information using the first-order to third-order color information based on the thinking of the Neugebauer's expression, and color mixture information is estimated. Color information of each of pixels in a target image is then determined from the result of the estimation and the image is displayed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a color mixing simulation apparatus, a color mixing simulation method, and a program for simulating color mixing using ink.

  Printing of building materials and the like is generally performed by a gravure printing method. Here, in gravure printing for magazines and the like, it is common to use four colors of ink called process colors such as cyan, magenta, yellow, and black. In gravure printing for building materials, etc., ink suitable for the purpose and application is used. Used. This is because it uses colors that match the required physical properties (adhesiveness, weather resistance, etc.), but also because it produces colors that are difficult to express with process colors. Therefore, in the printing work for building materials and the like, the process of determining the color of ink is important.

In such operations, for example, digital output having a color tone similar to a printed matter by gravure printing or the like may be required. In such a case, the retouching operation is generally performed by adjusting the color tone while comparing the target printed matter with the computer screen. However, the retouching work must be performed by a skilled person and is a heavy work. Even if the color tone can be adjusted, when performing gravure printing with the same color tone, it is necessary to reversely adjust the color tone of the printed matter by gravure printing or the like to the digital output. On the other hand, as another method, by creating a profile based on the colorimetric values collected from the target printed matter and using the profile, a digital output with high consistency with the printed matter can be obtained. Here, the profile is information corresponding to a dictionary in color conversion. In particular, an ICC (International Color Consortium) standard compliant profile is called an ICC profile. As disclosed in Patent Document 1, the present inventors have proposed a mechanism for reducing the burden of color determination work using a profile. According to the invention disclosed in Patent Document 1, the burden of color determination work is greatly reduced.
JP 2006-187964 A

However, even with the invention disclosed in Patent Document 1, it is necessary to perform a retouching operation for ink for which a profile has not been created.
For this reason, attempts have been made to simulate color mixing for inks for which no profile has been created, but the subtractive color calculation method is a complex model, so interactive processing can be performed while maintaining color reproduction accuracy. The performance which can be endured was not able to be demonstrated.

  The present invention has been made in view of the above-described problems, and the object thereof is a color mixing simulation for simulating ink color mixing that can exhibit sufficient performance for interactive processing while maintaining the accuracy of color reproduction. Is to provide a device.

In order to achieve the above-described object, the first invention estimates color mixing information using colorimetric information holding means for holding colorimetric information which is a colorimetric result of a printed matter and arbitrarily selected primary color information. Colorimetric information search means for searching for the colorimetric information that is an interpolation calculation target, high-order color information estimation means for estimating high-order color information for the primary color information, the primary color information, and the A color mixing simulation apparatus comprising: color mixing information estimation means for estimating color mixing information by performing interpolation on the retrieved color measurement information using high-order color information.
Further, the colorimetric information search means may search for the colorimetric information including a primary color that is closest to the arbitrarily selected primary color information.
Furthermore, it is desirable to include first color information determination means for determining color information of each pixel of an arbitrary image using the color mixture information estimated by the color mixture information estimation means.

The color mixture information estimated by the color mixture information estimation unit may be a combination of gradations necessary for creating a profile.
It is desirable to further comprise profile creating means for creating the profile, and second color information determining means for determining color information of each pixel of an arbitrary image using the created profile.

According to a second aspect of the present invention, there is provided a step of holding colorimetric information which is a colorimetric result of a printed matter, and the colorimetric information which is an interpolation calculation target when estimating color mixture information using arbitrarily selected primary color information A step of estimating high-order color information for the primary color information, and using the primary color information and the high-order color information, performing an interpolation operation on the searched colorimetric information, And a step of estimating the color mixture information.
The step of searching for colorimetric information may search for the colorimetric information including a primary color that is closest to the arbitrarily selected primary color information.
Furthermore, it is desirable to include a step of determining color information of each pixel of an arbitrary image using the color mixture information estimated by the step of estimating the color mixture information.

Further, the color mixture information estimated by the step of estimating the color mixture information may be a combination of gradations necessary for creating a profile.
Preferably, the method further includes a step of creating the profile and a step of determining color information of each pixel of an arbitrary image using the created profile.

  A third invention is a program for causing a computer to function as the color mixing simulation apparatus according to any one of claims 1 to 5.

  According to the present invention, it is possible to provide a color mixing simulation apparatus that performs color mixing simulation that can exhibit sufficient performance to perform interactive processing while maintaining color reproduction accuracy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The first embodiment will be described in detail.
FIG. 1 is a hardware configuration diagram of a computer that realizes a color mixing simulation apparatus 1 according to the present embodiment.
In the color mixing simulation apparatus 1, a control unit 3, a storage unit 5, a media input / output unit 7, a communication control unit 9, an input unit 11, a display unit 13, a peripheral device I / F unit 15 and the like are connected via a bus 17. The

  The control unit 3 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

The CPU calls a program stored in the storage unit 5, ROM, recording medium, etc. to a work memory area on the RAM, executes it, drives and controls each device connected via the bus 17, and the color mixing simulation device 1 The processing to be described later (see FIG. 5) is realized.
The ROM is a non-volatile memory and permanently holds a computer boot program, a program such as BIOS, data, and the like.
The RAM is a volatile memory, and temporarily stores programs, data, and the like loaded from the storage unit 5, ROM, recording medium, and the like, and includes a work area used by the control unit 3 for performing various processes.

The storage unit 5 is an HDD (hard disk drive), and stores a program executed by the control unit 3, data necessary for program execution, an OS (operating system), and the like. As for the program, a control program corresponding to an OS (operating system) and an application program corresponding to processing described later are stored.
Each of these program codes is read by the control unit 3 as necessary, transferred to the RAM, read by the CPU, and executed as various means.

  The media input / output unit 7 (drive device) performs data input / output. For example, a floppy (registered trademark) disk drive, a CD drive (-ROM, -R, RW, etc.), a DVD drive (-ROM, -R, -RW etc.) and media input / output devices such as MO drives.

  The communication control unit 9 includes a communication control device, a communication port, and the like, and is a communication interface that mediates communication between the computer and the network 19, and performs communication control between other computers via the network 19.

The input unit 11 inputs data and includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad.
An operation instruction, an operation instruction, data input, and the like can be performed on the computer via the input unit 11.

  The display unit 13 includes a display device such as a CRT monitor and a liquid crystal panel, and a logic circuit (such as a video adapter) for realizing a video function of the computer in cooperation with the display device.

  The peripheral device I / F (interface) unit 15 is a port for connecting a peripheral device to the computer, and the computer transmits and receives data to and from the peripheral device via the peripheral device I / F unit 15. The peripheral device I / F unit 15 is configured by USB, IEEE 1394, RS-232C, or the like, and usually has a plurality of peripheral devices I / F. The connection form with the peripheral device may be wired or wireless.

  The bus 17 is a path that mediates transmission / reception of control signals, data signals, and the like between the devices.

Next, the configuration of the color mixing simulation apparatus 1 will be described with reference to FIG.
FIG. 2 is a schematic configuration diagram of the color mixing simulation apparatus 1.

  The color mixing simulation apparatus 1 includes a colorimetric information database 21, a primary color information input screen display unit 23, a primary color information input unit 25, a colorimetric information search unit 27, a high-order color information estimation unit 29, and a color mixing information estimation unit 31. , First color information determination means 33, image output means 35, and the like.

  The color measurement information database 21 as color measurement information holding means holds color measurement information which is a color measurement result of a printed matter. The colorimetric information database 21 holds the original name of printing, the ink name, the printing plate conditions of each ink unit, the combination of gradation values, and the colorimetric value when the combination is printed. Here, the colorimetric values are assumed to be expressed in a standard color space (L * a * b *). The color space (L * a * b *) is a chromaticity diagram called CIE 1976 L * a * b * proposed in 1976 by the CIE (Commission Internationale de L'eclairage). Hue is expressed by two parameters, a * axis (red to green) and b * axis (blue to yellow), and a color is defined by adding a parameter of lightness L * axis. The colorimetric information database 21 holds all colorimetric values for paper color, primary color, high-order color, and mixed color to be estimated, which will be described later.

The primary color information input screen display means 23 displays a primary color information input screen which is a primary color input screen. The primary color refers to the color of the ink, and the multiplication of the primary colors is a mixed color. The number of primary colors is usually three or four, but in order to avoid confusion, the following description will be made assuming that the primary colors are three.
It is to be noted that an object of the present invention is to select a color that is not included in the primary color of the color measurement information held in the color measurement information database 21 and perform a color mixture simulation. Therefore, in the following description, the input primary color is different from the primary color of the color measurement information held in the color measurement information database 21. However, when colorimetric information that completely matches the input primary color information is stored in the colorimetric information database 21, an arbitrary image may be displayed using the colorimetric information.
On the primary color information input screen, a text box for inputting each parameter of the color space (L * a * b *) may be arranged, or a color picker may be arranged. Here, the color picker refers to a screen item that allows an arbitrary color to be selected by a color chart (color chart) or the like.

  The primary color information input unit 25 inputs primary color information. Data is input by interactive processing via the input unit 11. As for the paper color of the printed matter, predetermined L *, a *, and b * values may be held in the storage unit 5 or may be input together with primary color information.

ただし、△Ｅ：色差、Ｌ１：選択された１次色情報のＬ*値、ａ１：選択された１次色情報のａ*値、ｂ１：選択された１次色情報のｂ*値、Ｌ２：測色情報の１次色情報のＬ*値、ａ２：測色情報の１次色情報のａ*値、ｂ２：測色情報の１次色情報のｂ*値である。
尚、検索した最近似情報は、ＲＡＭ上のワークメモリ領域に保持する。 The colorimetric information search unit 27 searches for colorimetric information that is an interpolation calculation target when estimating color mixture information using arbitrarily selected primary color information. For example, the most approximate information that is colorimetric information including a primary color that is closest to the arbitrarily selected primary color information is searched. Specifically, the color difference is calculated for each primary color information of the three colors, and the colorimetric information that minimizes the sum of the color differences is the closest approximation information. Here, the color difference means a difference between two colors expressed in the color space (L * a * b *) described above, and is calculated by the following equation.

Where ΔE: color difference, L1: L * value of the selected primary color information, a1: a * value of the selected primary color information, b1: b * value of the selected primary color information, L2 : L * value of primary color information of colorimetric information, a2: a * value of primary color information of colorimetric information, b2: b * value of primary color information of colorimetric information.
The searched approximate information is held in a work memory area on the RAM.

Higher order color information estimation means 29 estimates higher order color information for the primary color information. Here, the higher order color refers to a secondary color or higher. The secondary color is a color obtained by multiplying the two primary colors, and the tertiary color is a color obtained by multiplying the three primary colors. These are defined as secondary colors and tertiary colors, and are used separately from mixed colors.
The higher-order color is estimated on the assumption that the Lambert = Beer law is satisfied, for example.

ただし、Ｉ０：入射光の強度、Ｉ：透過光の強度、ｋ：定数、ｃ：吸収物質の濃度、ｄ：吸収媒体の厚さである。
ここで、Ｄ＝ｋ×ｃ×ｄは、吸光度または光学濃度と呼ばれる。 Here, with reference to FIG. 3, estimation of higher-order color information when it is assumed that the Lambert-Beer law is established will be described.
The Lambert-Beer law means that the logarithm of light attenuation is proportional to the concentration of the absorbing material and the thickness of the absorbing medium, and is expressed by the following equation.

Here, I0: intensity of incident light, I: intensity of transmitted light, k: constant, c: concentration of absorbing material, d: thickness of absorbing medium.
Here, D = k × c × d is called absorbance or optical density.

ここで、Ｘ、Ｙ、Ｚ：対象とする物体の三刺激値、Ｘｎ、Ｙｎ、Ｚｎ：完全拡散反射面の三刺激値であり、Ｙｎ＝１００と規格化する。
ただし、関数ｆは、例えば、ｆ（Ｘ／Ｘｎ）で、次式のとおりである。

関数ｆ（Ｙ／Ｙｎ）、ｆ（Ｚ／Ｚｎ）も同様である。 First, estimation of secondary color information will be described.
FIG. 3 is a schematic diagram showing estimation of secondary color information.
Here, since the printed matter is an object, the transmitted light of the above formula 2 is replaced with reflected light.
45 indicates the intensity I1 of the reflected light with respect to the U1 ink 41, 47 indicates the intensity I2 of the reflected light with respect to the U2 ink 43, and 49 indicates the intensity I12 of the reflected light when the U1 ink 41 and the U2 ink 43 are multiplied by 100%. ing.
Assuming that the optical density of the U1 ink 41 is D1, the optical density of the U2 ink 43 is D2, and the optical density obtained by multiplying the U1 ink 41 and the U2 ink 43 by 100% is D12, it is assumed that D12 = D1 + D2. From the Lambert-Beer law and the logarithmic nature, the relation I12 = I1 × I2 ÷ I0 can be derived. By applying this relational expression to the tristimulus values X, Y, and Z, tristimulus values X12, Y12, and Z12 obtained by multiplying the ink amounts of the U1 ink 41 and the U2 ink 43 by 100% can be obtained. Further, from the tristimulus values X12, Y12, and Z12, L *, a *, and b * values obtained by multiplying the U1 ink 41 and the U2 ink 43 by an ink amount of 100% can be calculated.
The values of L *, a *, and b * are calculated using the following formula.

Here, X, Y, Z: Tristimulus values of the target object, Xn, Yn, Zn: Tristimulus values of the completely diffusive reflecting surface, and normalized as Yn = 100.
However, the function f is, for example, f (X / Xn) as shown in the following equation.

The same applies to the functions f (Y / Yn) and f (Z / Zn).

Next, estimation of tertiary color information will be described.
The optical density of U1 ink 41 is D1, the optical density of U2 ink 43 is D2, the optical density of U3 ink is D3, and the optical density of U1 ink 41, U2 ink 43 and U3 ink multiplied by 100% is D123. Assuming that the intensity of the reflected light of the 100% ink amount of U1 ink 41, U2 ink 43, and U3 ink is I123, assuming that D123 = D1 + D2 + D3, the relationship from the Lambert-Beer law and the logarithmic nature The expression I123 = I1 × I2 × I3 ÷ I0 ^ 2 (x ^ y represents x to the power of y) can be derived. By applying this relational expression to the tristimulus values X, Y, and Z, tristimulus values X123, Y123, and Z123 obtained by multiplying the ink amounts of the U1 ink 41, the U2 ink 43, and the U3 ink by 100% can be obtained. . Further, from the tristimulus values X123, Y123, and Z123, L *, a *, and b * values obtained by multiplying the U1 ink 41, the U2 ink 43, and the U3 ink by an ink amount of 100% can be calculated.
The calculation of the values of L *, a *, and b * is the same as the estimation of secondary color information.

The color mixture information estimation means 31 estimates the color mixture information by performing an interpolation operation on the retrieved colorimetric information using the primary color information and the high order color information.
The interpolation calculation is performed based on the concept of Neugebauer's formula, for example.

ただし、Ｒ、Ｇ、Ｂ：反射率、Ｒｘ、Ｇｘ、Ｂｘ：ｘ部分の反射率、ｃ、ｍ、ｙ：網点面積率である。 Here, the Neugebauer equation will be described with reference to FIG.
The Neugebauer equation is an equation representing the relationship between the reflectance and the dot area ratio, and is represented by the following equation.

However, R, G, B: reflectance, Rx, Gx, Bx: reflectance of x portion, c, m, y: halftone dot area ratio.

FIG. 4 is a schematic diagram showing the multiplication of the three color ink units. The ink unit is illustrated by a region surrounded by a circle, and the crossing of the ink units is illustrated by a region where two or more regions overlap.
51 is a primary color of W (paper white), 53 is a primary color of only C (cyan), 55 is a primary color of only M (magenta), 57 is a primary color of only Y (yellow), and 59 is C (cyan) · M ( Magenta) 100% multiplied secondary color, 61 is M (magenta) Y (yellow) 100% multiplied secondary color, 63 is C (cyan) Y (yellow) A secondary color 65 multiplied by 100% of ink and 65 represents a tertiary color multiplied by 100% of C (cyan), M (magenta), and Y (yellow). These eight colors coincide with the symbols w, c, m, y, cm, my, yc, and cym used in Equation 4.
C (cyan), M (magenta), and Y (yellow) are examples of colors of primary color information input by the primary color information input means 25, and are naturally limited to these colors. is not. The same applies to the following description.

  In the interpolation calculation based on the concept of Neugebauer's formula, first, one color mixture X to be simulated is determined. Next, the halftone dot area ratio shown in FIG. 4 when the ink amount corresponding to the mixed color X is reproduced is obtained. Then, the value obtained by multiplying the difference between the L *, a *, and b * values of the eight colors of the most approximate information and the L *, a *, and b * values of the input or estimated eight colors by the halftone dot area ratio Is added to the values of L *, a *, and b * of the color mixture X of the closest approximation information.

As an example, a description will be given of the estimation of the mixed color mixture X when the ink amount is (Xc, Xm, Xy) = (70%, 70%, 0%).
First, the halftone dot area ratio of 8 colors is obtained.
The halftone dot area ratio of W is (1−Xc) × (1−Xm) × (1−Xy) = 0.3 × 0.3 × 1 = 0.09.
The halftone dot area ratio of C is Xc × (1−Xm) × (1−Xy) = 0.7 × 0.3 × 1 = 0.21.
The halftone dot area ratio of M is (1−Xc) × Xm × (1−Xy) = 0.3 × 0.7 × 1 = 0.21.
The halftone dot area ratio of Y is (1−Xc) × (1−Xm) × Xy = 0.3 × 0.3 × 0 = 0.
The dot area ratio of C · M is Xc × Xm × (1−Xy) = 0.7 × 0.7 × 1 = 0.49.
The dot area ratio of M · Y is (1−Xc) × Xm × Xy = 0.3 × 0.7 × 0 = 0.
The dot area ratio of C · Y is Xc × (1−Xm) × Xy = 0.7 × 0.3 × 0 = 0.
The dot area ratio of C, M, and Y is Xc × Xm × Xy = 0.7 × 0.7 × 0 = 0.

Next, the value of L * of the mixed color X is obtained. The calculation formula is: L * of X = L * of the most approximate information + W halftone dot area ratio × (L * of the most approximate information W−L * of input W) + C halftone dot area ratio × (recently Similar information C L * −input C L *) + M halftone dot area ratio × (M approximate L * of the approximate information−input M L *) + Y halftone dot area ratio × (most approximate information) L * of Y−L * of input Y + C + M halftone dot area ratio × (C * M L * of the most approximate information−estimated C * M L *) + M * Y halftone dot area Rate × (M · Y L * of the most approximate information−L * of the estimated M · Y) + C • Y halftone dot area ratio × (L * of C · Y of the most approximate information−estimated C · Y L *) + C • M • Y halftone dot area ratio × (C * M • Y L * of the most approximate information−L * of estimated C • M • Y) = L * of the most approximate information X * + 0. 09 × (L * of the most approximate information W−L * of the input W) + 0.21 × (L * of the most approximate information C−the input C L *) + 0.21 × (L * of M of the most approximate information−L * of input M) + 0.49 × (L * of the most approximate information C * M−L * of estimated C • M) is there.
Note that the value of L * of W may be a value held in the storage unit 5.
Similarly, the values of a * and b * of the mixed color X can be obtained.
In the above description, C, M, and Y have been described based on Neugebauer's formula, but in the present invention, they correspond to U1 ink, U2 ink, and U3 ink, respectively.

  The first color information determination unit 33 uses the color mixture information estimated by the color mixture information estimation unit 31 to determine color information of each pixel of an arbitrary image. Here, the color information is determined from a device-independent color space (L *, a *, b *) to a device-dependent color space (for example, an RGB color space used when output to the display unit 13). Including color conversion. Since the mechanism of this color conversion is well known, the description thereof is omitted.

  The image output means 35 outputs an image according to the color information of each pixel determined by the first color information determination means 33.

Next, details of the operation of the color mixing simulation apparatus 1 will be described with reference to FIG.
FIG. 5 is a flowchart showing a processing procedure of the color mixing simulation apparatus 1.

  As shown in FIG. 5, when the display command information of the primary color information input screen is input via the input unit 11, the control unit 3 displays the primary color information input screen (step 101).

  Next, when primary color information is input via the input unit 11 (step 102), the control unit 3 refers to the color measurement information database 21 and primary colors of the primary color information and the color measurement information. Is calculated (step 103). Here, since the color difference is calculated for each primary color information of the three colors, three color differences are calculated. The combination for calculating the color difference is the same unit such as U1 ink of primary color information and U1 ink of primary color of colorimetric information. The color difference is calculated for all colorimetric information of the same original fabric.

Next, the control unit 3 extracts colorimetric information with the smallest sum of color differences as the most approximate information (step 104).
The most approximate information is determined as the colorimetric information having the smallest sum of color differences, but may be other conditions.

  Next, the control unit 3 estimates secondary color and tertiary color information (step 105). That is, assuming the aforementioned Lambert-Beer law, the secondary color and tertiary color information are estimated from the primary color information.

  Next, the control unit 3 estimates the color mixture information from the primary color information and the most approximate information (step 106). That is, based on the concept of the Neugebauer equation described above, the color mixture information is estimated by performing an interpolation operation on the most approximate information extracted in step 104 using the primary to tertiary color information.

  Next, the control unit 3 determines color information of each pixel of the target image from the estimation result (step 107). The determined color information is stored in a work memory area on the RAM, for example.

Next, the control unit 3 displays an image according to the color information determined in step 107 (step 108).
The operator confirms the displayed image, and if it is not the desired color, the operator can repeat from step 101 and display an image using different primary color information.

  As described above in detail, according to the first embodiment, the color difference between the input primary color information and the primary color of the color measurement information is calculated with reference to the color measurement information database 21, Colorimetric information with the smallest sum of color differences is extracted as the most approximate information. Next, assuming the Lambert-Beer law, the secondary color and tertiary color information is estimated from the primary color information. Next, based on the idea of Neugebauer's formula, interpolation calculation is performed on the closest approximation information using primary to tertiary color information, and color mixture information is estimated. Then, the color information of each pixel of the target image is determined from the estimation result, and the image is displayed.

  According to the first embodiment, an operator causes a color mixing simulation to be performed with a sufficiently practical response time in the interactive processing even for a color mixing that is not included in the primary color of the colorimetric information to be held. The image can be confirmed.

Next, the second embodiment will be described in detail.
FIG. 1 is a hardware configuration diagram of a computer that realizes a color mixing simulation apparatus 1a according to the present embodiment.
Since the hardware configuration is the same as that of the first embodiment, description thereof is omitted.

Next, the configuration of the color mixing simulation apparatus 1a will be described with reference to FIG.
FIG. 6 is a schematic configuration diagram of the color mixing simulation apparatus 1a.
Elements having the same functions as those shown in FIG. 2 are given the same numbers to avoid redundant description.

  The color mixing simulation apparatus 1a includes a colorimetric information database 21, a primary color information input screen display unit 23, a primary color information input unit 25, a colorimetric information search unit 27, a high-order color information estimation unit 29, and a color mixing information estimation unit 31. , A profile creation unit 37, a second color information determination unit 39, an image output unit 35, and the like.

  The profile creation unit 37 creates a profile based on the color mixture information estimated by the color mixture information estimation unit 31. Here, the color mixture information estimated by the color mixture information estimation means 31 is a combination of gradations necessary for creating a profile. For example, when creating an ICC profile, a combination of gradations necessary for creating a profile is determined based on the specifications of the published ICC profile.

  The second color information determination unit 39 uses the profile created by the profile creation unit 37 to determine color information of each pixel of an arbitrary image. Since the mechanism for determining color information using a profile is well known, the description thereof is omitted.

Next, details of the operation of the color mixing simulation apparatus 1a will be described with reference to FIG.
FIG. 7 is a flowchart showing a processing procedure of the color mixing simulation apparatus 1a.

  As shown in FIG. 7, when the display command information for the primary color information input screen is input via the input unit 11, the control unit 3 displays the primary color information input screen (step 201).

  Next, when primary color information is input via the input unit 11 (step 202), the control unit 3 refers to the color measurement information database 21 and primary colors of the primary color information and the color measurement information. (Step 203). Here, since the color difference is calculated for each primary color information of the three colors, three color differences are calculated. The combination for calculating the color difference is the same unit such as U1 ink of primary color information and U1 ink of primary color of colorimetric information. The color difference is calculated for all colorimetric information of the same original fabric.

Next, the control unit 3 extracts colorimetric information with the smallest sum of color differences as the most approximate information (step 204).
The most approximate information is determined as the colorimetric information having the smallest sum of color differences, but may be other conditions.

  Next, the control unit 3 estimates secondary color and tertiary color information (step 205). That is, assuming the aforementioned Lambert-Beer law, the secondary color and tertiary color information are estimated from the primary color information.

  Next, the control unit 3 estimates color mixture information that is a combination of gradations necessary for profile creation from the primary color information and the most approximate information (step 206). That is, based on the concept of Neugebauer's equation described above, color mixing information that is a combination of gradations necessary for profile creation is performed by performing an interpolation operation on the most approximate information extracted in step 204 using primary to tertiary color information. Is estimated.

  Next, the control unit 3 creates a profile from the estimation result (step 207). The created profile is preferably stored in the storage unit 5 by displaying a screen for inputting a file name and allowing the operator to input the file name.

  Next, when profile designation information is input via the input unit 11 (step 208), the control unit 3 applies the profile to the target image and determines color information (step 209). The determined color information is stored in a work memory area on the RAM, for example.

Next, the control unit 3 displays an image according to the color information determined in step 209 (step 210).
The operator checks the displayed image, and if it is not a desired color, the operator can repeat from step 201 and display an image using different primary color information.

  As described above in detail, according to the second embodiment, the color difference between the input primary color information and the primary color of the color measurement information is calculated with reference to the color measurement information database 21, Colorimetric information with the smallest sum of color differences is extracted as the most approximate information. Next, assuming the Lambert-Beer law, the secondary color and tertiary color information is estimated from the primary color information. Next, based on the idea of Neugebauer's formula, interpolation calculation is performed on the most approximate information using primary to tertiary color information, and color mixture information that is a combination of gradations necessary for profile creation is estimated. Then, a profile is created from the estimation result, color information is determined by applying the created profile, and an image is displayed.

  According to the second embodiment, an operator can perform color mixing simulation with a sufficiently practical response time in interactive processing even for color mixing that is not included in the primary color of the colorimetric information to be held. The image can be confirmed. Furthermore, the simulation result can be saved as a profile and used secondarily.

  5 and 7 may be distributed by being stored in a recording medium such as a CD-ROM or transmitted / received via a communication line.

  The preferred embodiments of the color mixing simulation apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

Hardware configuration diagram of a computer realizing the color mixing simulation apparatus 1 Schematic configuration diagram of the color mixing simulation apparatus 1 Schematic diagram showing estimation of secondary color information Schematic diagram showing the combination of three color ink units The flowchart which shows the process sequence of the color mixing simulation apparatus 1 Schematic configuration diagram of the color mixing simulation apparatus 1a The flowchart which shows the process sequence of the color mixing simulation apparatus 1a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ......... Color-mixing simulation apparatus 3 ......... Control part 5 ......... Storage part 7 ......... Media input / output part 9 ......... Communication control part 11 ......... Input part 13 ......... Display part 15 ......... Peripheral device I / F unit 17 ......... Bus 19 ......... Network unit 21 ......... Color measurement information database 41 ......... U1 ink 43 ......... U2 ink 45 ......... Intensity of reflected light I1 against U1 ink 41
47 .... Intensity of reflected light I2 with respect to U2 ink 43
49... Reflected light intensity I12 with respect to the multiplication of 100% ink amount of U1 ink 41 and U2 ink 43
51 ... W
53 ... …… C
55 ... …… M
57 ......... Y
59 ……… CM
61 ……… MY
63 ......... CY
65 ……… CMY

Claims (11)

Colorimetric information holding means for holding colorimetric information which is a colorimetric result of the printed matter;
Colorimetric information search means for searching for the colorimetric information that is an interpolation calculation target when estimating color mixture information using arbitrarily selected primary color information;
High-order color information estimation means for estimating high-order color information for the primary color information;
Using the primary color information and the high-order color information, interpolating the retrieved colorimetric information to estimate color mixture information;
A color mixing simulation apparatus comprising:   2. The color mixing simulation apparatus according to claim 1, wherein the colorimetric information search unit searches the colorimetric information including a primary color that is closest to the arbitrarily selected primary color information.   The first color information determination unit that determines color information of each pixel of an arbitrary image using the color mixture information estimated by the color mixture information estimation unit. Color mixing simulation device. The color mixture information estimated by the color mixture information estimation means is:
The color mixing simulation apparatus according to claim 1, wherein the color combination is a combination of gradations necessary for creating a profile. Profile creation means for creating the profile;
Second color information determining means for determining color information of each pixel of an arbitrary image using the created profile;
The color mixing simulation apparatus according to claim 4, further comprising: A step of holding colorimetric information which is a colorimetric result of the printed matter;
Searching the colorimetric information which is an interpolation calculation target when estimating color mixture information using arbitrarily selected primary color information;
Estimating high-order color information for the primary color information;
Using the primary color information and the high-order color information, performing an interpolation operation on the searched colorimetric information, and estimating color mixture information;
A color mixing simulation method comprising:   The color mixing simulation method according to claim 6, wherein the step of searching for the colorimetric information includes searching for the colorimetric information including a primary color that is closest to the arbitrarily selected primary color information.   The color mixing simulation method according to claim 6, further comprising: determining color information of each pixel of an arbitrary image using the color mixing information estimated by the step of estimating the color mixing information. The color mixture information estimated by the step of estimating the color mixture information is:
The color mixing simulation method according to claim 6, wherein a combination of gradations necessary for creating a profile is used. Creating the profile;
Determining color information of each pixel of an arbitrary image using the created profile;
The color mixing simulation method according to claim 9, further comprising:   A program that causes a computer to function as the color mixing simulation apparatus according to any one of claims 1 to 5.

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