JP2014078900A - Color output device, color correction device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color output device, color correction device, and program for appropriately performing color correction so that a person whose color sense is deteriorated by aging or a color blind person can sense color as well as a young person or a healthy person.SOLUTION: X, Y, and Z of color output (displayed, projected, or printed) by a predetermined device are color-corrected to be X, Y, and Zby using 9 correction coefficients c(i=1, 2, and 3; j=1, 2, and 3). The correction coefficients care determined so that the X, Y, and Zafter the correction minimize color difference between color sensed by an old person (a color blind person) and original color. Expression in which influence of reduction in crystalline lens transmittance or reduction in a pupil diameter is reflected is used in calculating the color sensed by the old person (the color blind person).

Description

  The present invention relates to a color output device, a color correction device, and a program.

  As is well known, elderly people usually have various physical functions that are lower than younger ones, among which there is a reduction in color vision. Specifically, it is considered that the color becomes darker or yellowish as it gets older, which may cause trouble in daily life. With the progress of an aging society, it can be said that the problem of declining color vision due to aging is becoming a larger social problem. Of course, in addition to the decrease in color vision due to aging, some people have color vision abnormalities (congenital or acquired).

  Therefore, if various products that use color are equipped with a function that enables color perception to be similar to that of young people and healthy people, even if there is a decline or abnormal color vision, It is desirable to be able to respond to the demands of society aiming to coexist with the disabled and disabled. Of course, it can be said that it has even greater significance in occupations that require accurate color perception. There have been several proposals for these technologies. For example, Patent Document 1 below discloses an image processing apparatus that corrects displayed colors according to age.

Japanese Patent No. 3552413

  In Patent Document 1, color correction is performed by a method of correcting the R, G, and B values of the color according to the lens transmittance at the age. However, when the inventor tried to color-correct a large number of images using the method of Patent Document 1, there was an example in which the so-called white-out, in which the brightness of the color became too high and became white, was observed. In the case of overexposure, it is unlikely that the elderly will perceive the same color as the young.

  The reason for this is that the method of correcting the R, G, and B values of the color produces only a result of simply increasing (amplifying) the R, G, and B values as the age increases, and is therefore appropriate. It is possible that this is not a correction. Therefore, development of a method other than simply correcting the R, G, and B values is desired. In addition, there is an accumulation of scientific (medical) knowledge other than that related to the lens transmittance regarding the decrease in color vision due to aging (or abnormal color vision), and these should also be used appropriately. .

  Therefore, in view of the above, the problem to be solved by the present invention is to appropriately perform color correction so that a person whose color vision has deteriorated due to aging or a person with color vision abnormality can perceive color in the same way as a young person or a healthy person. A color output device, a color correction device, and a program are provided.

  In order to solve the above problems, a color output device according to the present invention has an output means for outputting a color, and a user who perceives the color output by the output means has a color sense different from that of a young healthy person. An XYZ color system so that the perception by the user of the color output from the output means approaches the perception of a young healthy person in accordance with the input received by the input means Correction means for correcting the color output from the output means by adjusting the contribution of R, G, and B in the RGB color system in each of X, Y, and Z. . Thus, for example, the elderly and color blind persons can be compared with young healthy individuals by a novel method of adjusting the contribution of R, G, B in the RGB color system in each of X, Y, Z of the XYZ color system. A color output device that performs color correction so that similar colors can be perceived can be realized.

  The input means is age input means for receiving information on the age of the user, and the correction means is based on the age information received by the age input means in accordance with X, Y, Z of the XYZ color system. The contributions of R, G, and B in the RGB color system may be adjusted. Accordingly, for example, the elderly or color vision can be detected by a novel method of adjusting the contributions of R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system according to the age of the user. Color correction can be performed so that an abnormal person perceives the same color as a young healthy person.

  In addition, the correction means may cancel R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system so as to cancel the influence of the decrease in the lens transmittance of the user according to age. The contribution may be adjusted. Thereby, depending on the age of the user, the contribution of R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system so as to cancel the influence of the decrease in the lens transmittance of the user By a novel method of adjusting the degree, color correction can be performed so that, for example, an elderly person or a color blind person can perceive the same color as a young healthy person.

  In addition, the correction means cancels the influence of the reduction of the pupil diameter of the user according to the age, and the RGB color system R, G, B in the X, Y, Z of the XYZ color system, respectively. The contribution may be adjusted. Thereby, according to the age of the user, the contribution of R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system so as to cancel the influence of the reduction of the diameter of the pupil of the user By a novel method of adjusting the degree, color correction can be performed so that, for example, an elderly person or a color blind person can perceive the same color as a young healthy person.

  Further, the input means is a type input means for receiving information on the type of color vision abnormality of the user, and the correction means is an XYZ color system according to the information on the type of color vision abnormality received by the type input means. The contributions of R, G, and B in the RGB color system in each of X, Y, and Z may be adjusted. Thus, according to the novel method of adjusting the contribution of R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system according to the type of color blindness of the user, for example, Color correction can be performed so that a person or a person with color blindness can perceive the same color as a young healthy person.

  The output means may be a display means for displaying a color. Thus, the display means for displaying colors can be used, for example, by using a new method of adjusting the contribution of R, G, and B in the RGB color system in each of X, Y, and Z in the XYZ color system. Color correction can be performed so that a person or a person with color blindness can perceive the same color as a young healthy person.

  The output means may be a projection means for projecting colors. Thus, the projection means for projecting the color, for example, by the new method of adjusting the contributions of R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system, Color correction can be performed so that a person or a person with color blindness can perceive the same color as a young healthy person.

  The output means may be a printing means for printing a color. Thus, the printing means for printing the color can be applied, for example, by the new method of adjusting the contributions of R, G, and B in the RGB color system in each of X, Y, and Z in the XYZ color system. Color correction can be performed so that a person or a person with color blindness can perceive the same color as a young healthy person.

  The color correction apparatus according to the present invention is a color correction apparatus provided in a color output apparatus including an output means for outputting a color, and the output means received by the input means provided in the color output apparatus. Acquisition means for acquiring an input indicating that a user who perceives the color output by the user has color vision different from that of a young healthy person, and output from the output means according to the input acquired by the acquisition means By adjusting the contribution of R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system so that the perception of the color by the user approaches that of a young healthy person, Correction means for correcting the color output from the output means. Thus, for example, the elderly and color blind persons can be compared with young healthy individuals by a novel method of adjusting the contribution of R, G, B in the RGB color system in each of X, Y, Z of the XYZ color system. A color correction apparatus that performs color correction so that similar colors are perceived can be realized.

  Further, the program according to the present invention provides a computer provided in a color output device including an output unit that outputs a color, and the color output by the output unit received by the input unit provided in the color output device. Acquisition means for acquiring an input indicating that a user who perceives a color sense different from that of a young healthy person, and the user of the color output from the output means according to the input acquired by the acquisition means Output from the output means by adjusting the contribution of R, G, B of the RGB color system in each of X, Y, Z of the XYZ color system so that the perception of And functioning as a correcting means for correcting the color to be generated. Thus, for example, the elderly and color blind persons can be compared with young healthy individuals by a novel method of adjusting the contribution of R, G, B in the RGB color system in each of X, Y, Z of the XYZ color system. A program for color correction can be realized so that similar colors are perceived.

The figure which shows the display apparatus as 1st Embodiment of the color output device of this invention. The figure which shows the projector as 2nd Embodiment of the color output device of this invention. The figure which shows the printing apparatus as 3rd Embodiment of the color output device of this invention. The flowchart which shows the example of the process sequence in this invention. The figure which shows the conversion from RGB color system to XYZ color system. The figure which shows the example of the lens transmittance | permeability for every age. The figure which shows the example of the miosis rate for every age. The figure which shows the change of XYZ by aging. The figure which shows the example of the color correction type | formula in this invention. The figure which shows the example of the determination method of a correction coefficient. The figure which shows the example of the color difference in a proposal method and the conventional method.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram conceptually showing the internal structure of a display device 1a as a first example of the color output device of the present invention. The display device 1a is, for example, a television receiver, a computer (personal computer), a mobile phone, a smartphone, or a tablet terminal, and includes a control unit 2, an input unit 3, and a display unit 4 as internal configurations.

  The control unit 2 is a part that controls the overall control of the display device 1. The input unit 3 has a known structure such as a button, a numeric keypad, and a mouse, and is a part that receives input from the user. The input content input to the input unit 3 is sent to the control unit 2. The display unit 4 includes, for example, a liquid crystal display, and is a part that displays display contents (images and characters, as well as moving images and still images) commanded from the control unit 2. The display unit 4 is a display unit that can display a color image.

  The control unit 2 has the same configuration as that of a normal computer, and is necessary for information processing in the CPU 20 that controls various information processing such as calculations and commands, a RAM 21 as a volatile storage unit as a work area of the CPU 20, and the CPU 20. A ROM 22 is provided as a nonvolatile storage unit for storing data and programs. The ROM 22 may be a rewritable memory such as an EEPROM or a hard disk.

  The ROM 22 stores an image output program 23 and a color correction program 24 relating to the present invention. The image output program 23 is a program for calculating display contents (for example, display images) to be displayed on the display unit 4 (for example, from data acquired by a not-shown receiving unit or external storage device). The color correction program 24 is a main part of the present invention, and when the display contents are calculated by the image output program 23, the color-blind person and the color-blind person (congenital or acquired) due to aging are displayed on the display unit 4. This is a program for correcting the displayed color so that a color similar to the color perceived by young people or healthy persons is perceived when the displayed color is viewed.

  The color correction program 24 may be stored in the ROM 22 from the beginning. For example, the color correction program 24 may be stored in the storage medium 10 and stored (installed) in the ROM 24 later.

  Next, FIG. 2 is a diagram conceptually showing the internal configuration of the projector 1b as a second example of the color output apparatus of the present invention. In FIG. 2 and FIG. 3 to be described later, the parts having the same reference numerals as those in other figures are the same parts, and the duplicated explanation is omitted. The projector 1b in FIG. 2 is a device that projects a movie in a movie theater, for example, and includes a projection unit 5 and a display unit 6. The projection unit 5 projects the projection contents (color images and characters, as well as still images and moving images) on a predetermined projection plane according to a command from the control unit 2 according to a known structure. The display unit 6 is a part that displays information related to the control of the projector 1 b, and the operator looks at the display content displayed on the display unit 6 and makes an appropriate input through the input unit 3.

  FIG. 3 is a diagram conceptually showing the internal configuration of a printing apparatus 1c as a third example of the color output apparatus of the present invention. The printing apparatus 1 is a printer having a known structure such as an ink jet printer or a laser printer, and includes an ink supply unit 7 and a printing unit 8. In accordance with a command from the control unit 2, the ink supply unit 7 supplies the color ink to the printing unit 8 at the commanded ratio, and the printing unit 8 uses the print head to supply the color ink supplied from the ink supply unit 7 to a predetermined amount. Print on the target of printing (such as printing paper). In these examples, the control unit 2 is an embodiment of the color correction apparatus of the present invention.

  An example of a processing procedure in the color output device (and color correction device) illustrated in FIGS. 1 to 3 is shown in FIG. In the processing procedure of FIG. 4, processing other than manual processing by the user is processing described in the image output program 23 and the color correction program 24, and the CPU 20 may call these programs to the RAM 21 and automatically process them. .

  In the processing procedure of FIG. 4, first, a user (or an operator) inputs user information using the input unit 3 in S <b> 10. Here, the user refers to a person who views a color (image) output (displayed, projected, or printed) by the display device 1a, the projector 1b, and the printing device 1c. The user information is information related to the user's color vision, such as the age of the user, the degree or type of color vision abnormality of the user, and the like.

  Next, in S20, the control unit 2 performs color correction based on the user information input in S10 so that the color can be perceived in the same manner as a young person or a healthy person when the user is an elderly person or a color blind person. A correction coefficient is calculated. In addition, suppose that an elderly person points out all persons whose age is 20 years old as a young person, for example. Details of the correction coefficient and color correction using the correction coefficient will be described later.

  Next, in S <b> 30, the control unit 2 acquires image (color image) data, for example, in the RAM 21 using, for example, a not-shown receiving unit or external storage device. Characters, CG and illustrations may be used instead of images. Subsequently, in S40, the control unit 2 corrects (color correction) the color of the image or character formed in S30 using the correction coefficient calculated in S20. Details of this processing will also be described later.

  In step S50, the control unit 2 outputs an image (color) reflecting the color correction in step S40. In S60, when there are a plurality of images to be output (including moving images), it is determined whether or not output of all images has been completed (whether the moving images have been completed). If all the images have been output (S60: YES), the process of FIG. The above is the processing procedure of FIG.

  An example of specific processing contents in the determination of the correction coefficient in S20 and the color correction in S40 will be described below. In the following, an example will be described in which the color output device is the display device 1a and the color vision is lowered due to aging of the user. In this case, it is necessary to perform color correction in consideration of a decrease in color vision due to aging.

First, as is well known, in a color expression on a display device or the like, an RGB color system or an XYZ color system is used as a representative color system. FIG. 5 shows a conversion formula from the RGB color system to the XYZ color system in the form of a block diagram. That is, conversion from R (red), G (green), and B (blue) to X, Y, and Z is expressed by the following equations (E1) to (E3).
X = a ₁₁ R + a ₁₂ G + a ₁₃ B (E1)
Y = a ₂₁ R + a ₂₂ G + a ₂₃ B (E2)
Z = a ₃₁ R + a ₃₂ G + a ₃₃ B (E3)

The coefficients a ₁₁ , a ₁₂ , a ₁₃ , a ₂₁ , a ₂₂ , a ₂₃ , a ₃₁ , a ₃₂ , and a ₃₃ are the contribution of R to X, the contribution of G to X, and the contribution of B to X, respectively. Contribution, R contribution to Y, G contribution to Y, B contribution to Y, R contribution to Z, G contribution to Z, B contribution to Z It is considered that it is the quantity which shows. The nine parameters a ₁₁ to a ₃₃ are known constants. For example, a ₁₁ = 0.4124, a ₁₂ = 0.3576, a ₁₃ = 0.1805, a ₂₁ = 0.2126, a _{22 = 0.7152, a 23 = 0.0722,} a 31 = 0.0193, a 32 = 0.1192, is defined as a 33 = 0.9505.

Here, X _R , X _G , X _B , Y _R , Y _G , Y _B , Z _R , Z _G , and Z _B are defined by the following formulas (E4) to (E6). Further, when these are used, equations (E7) to (E9) are obtained.
X _R = a ₁₁ R, X _G = a ₁₂ G, X _B = a ₁₃ B (E4)
Y _R = a ₂₁ R, Y _G = a ₂₂ G, Y _B = a ₂₃ B (E5)
Z _R = a ₃₁ R, Z _G = a ₃₂ G, Z _B = a ₃₃ B (E6)
X = X _R + X _G + X _B (E7)
_{Y = Y R + Y G +} Y B (E8)
_{Z = Z R + Z G +} Z B (E9)

  Next, let us consider how the decrease in color vision due to aging is expressed by an expression. In this embodiment, attention is paid to the yellowing of the lens (decrease in transmittance) and the reduction of the pupil as factors for the decrease in color vision due to aging.

First, the yellowing of the lens due to aging is described. In the case of not considering color vision reduction due to aging, the above-mentioned X _j , Y _j , Z _j (j = R, G, B) are expressed by the following formulas (E10) to (E12) according to the spectral distribution of the display device 1a. Is done.
X _j = kΣS (iΔλ) x (iΔλ) f _j (iΔλ) Δλ (E10)
Y _j = kΣS (iΔλ) y (iΔλ) f _j (iΔλ) Δλ (E11)
Z _j = kΣS (iΔλ) z (iΔλ) f _j (iΔλ) Δλ (E12)

In the above equation, Δλ is an appropriately set step size relating to the wavelength, S (iΔλ) is the spectral distribution of the D65 white point with respect to the wavelength iΔλ, and x (iΔλ), y (iΔλ), and z (iΔλ) are the wavelengths iΔλ, respectively. X, Y, and Z color matching functions, f _R (iΔλ), f _G (iΔλ), and f _B (iΔλ) represent the red, green, and blue spectral distributions in the display unit 4, respectively. Also, Σ is a sum related to the integer i. When the range of the sum in Σ is i = i ₁ to i = i ₂ , if i ₁ and i ₂ are determined so that the entire visible light wavelength range is included in the range from i ₁ Δλ to i ₂ Δλ. Good. As can be easily understood, the above equation is a difference approximation in increments of Δλ. k may be an appropriate constant.

The above is a case of a young healthy person, but this changes as follows with aging. According to the well-known research of Pokorny et al., The light transmittance F of the lens of an A ₂ year old human (however, A ₂ should be A ₁ or more) relative to the A ₁ year old human lens is expressed by the following equation (E13 ). Here, ^ is a power and L is the optical density of the crystalline lens.
F (λ, A ₂ , A ₁ ) = 10 ^ {L (λ, A ₁ ) −L (λ, A ₂ )} (E13)

The optical density L of the crystalline lens is expressed by the following equation (E14) when A is greater than 20 and 60 or less, and when A is larger than 60, the optical density L of the lens is expressed by equation (E15). T _L1 and T _L2 are appropriate constants. An example of a plot of the lens transmittance F for each age is shown in FIG.
L (λ, A) = T _L1 (1 + 0.02 (A−32)) + T _L2 (E14)
L (λ, A) = T _L1 (1.56 + 0.0667 (A−60)) + T _L2 (E15)

When F is used, the equations (E10) to (E12) change from the following equations (E16) to (E18) with aging.
X ′ _j = kΣS (iΔλ) x (iΔλ) f _j (iΔλ) ΔλF (iΔλ, A ₂ , A ₁ ) (E16)
Y ′ _j = kΣS (iΔλ) y (iΔλ) f _j (iΔλ) ΔλF (iΔλ, A ₂ , A ₁ ) (E17)
Z ′ _j = kΣS (iΔλ) z (iΔλ) f _j (iΔλ) ΔλF (iΔλ, A ₂ , A ₁ ) (E18)

In the above formulas (E10) to (E12), X _j , Y _j , Z _j (j = R, G, B) of young people, X ′ _j , Y ′ _j of elderly people (E16) to (E18) , Z ′ _j (j = R, G, B) is defined as an effective component ratio. That is, the effective component ratio is defined by the following equations (E19) to (E21).
K _j ^(X) = X ′ _j / X _j (E19)
K _j ^(Y) = Y ′ _j / Y _j (E20)
K _j ^(Z) = Z ′ _j / Z _j (E21)

Next, pupil reduction due to aging will be described. According to the well-known study of Winn et al., The pupil reduction rate S is described by the following equation (E22). Here, M (A) is the diameter of the pupil at age A. By aging from A ₁ year old to A ₂ year old, all of the tristimulus values of X, Y, and Z decrease at this S ratio. An example of a plot of S is shown in FIG.
S = M (A ₂ ) / M (A ₁ ) (E22)

FIG. 8 is obtained by combining the above. FIG. 8 is a diagram showing a color vision reproduction in an elderly person in the form of a block diagram. Specifically, A tristimulus values X, Y, and Z perceived by a _one- year-old person (young person). from more a _2-year-old human elderly perceive when viewing the same color tristimulus values X ', Y', shows the expression to obtain Z '.

The conversion formula from X, Y, and Z shown in FIG. 8 to X ′, Y ′, and Z ′ is a formula that shows changes in tristimulus values due to aging. Comparing FIG. 5 and FIG. 8 using formulas (E4) to (E6), X, Y, Z perceived by young people and X perceived by older people when looking at the same color It can be seen that the contributions of R, G, and B change with aging (for example, the contribution of R to X is a ₁₁ whereas that of X, to X ' The contribution of _R is K _R ^(X) a ₁₁ , etc.).

In the present embodiment, based on the knowledge that the contribution of RGB in XYZ changes as a result of aging as described above, an expression for color correction for causing an older person to perceive the same X, Y, and Z as a younger person As shown in FIG. In FIG. 9, c _ij (i = 1, 2, 3; j = 1, 2, 3) is a correction coefficient.

Next, how the correction coefficient c _ij (i = 1, 2, 3; j = 1, 2, 3) is specifically determined will be described. FIG. 10 is an outline of a method for determining the correction coefficient c _ij (i = 1, 2, 3; j = 1, 2, 3).

In order to determine the correction coefficient c _ij , n sample colors are used. Respective X, Y, and Z are expressed as X (i), Y (i), and Z (i) (i = 1, 2,..., N).

The result of correcting (color correction) the n sample colors X (i), Y (i), Z (i) (i = 1, 2,..., N) with the above-described equation of FIG. , X _a (i), Y _a (i), Z _a (i) (i = 1, 2,..., N). Of course, X _a (i), Y _a (i), Z _a (i) (i = 1, 2,..., N) are c _ij (i = 1, 2, 3; j = 1, 2, It is a numerical value that changes depending on how to decide in 3).

These X _a (i), Y _a (i), Z _a (i) (i = 1, 2,..., N) are perceived by the elderly X, Y, Z (color vision reproduction of the elderly) Are set as X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,..., N). That is, X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,..., N) is expressed as X _a (i), Y _a (i), Z _a. (I) It is obtained from FIG. 8 from (i = 1, 2,..., N). At that time, the age of a young person (young healthy person) is, for example, 20 years old, and the age of a more elderly person is a variable. For each elderly person age, X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,..., n) is obtained.

X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,..., N) thus obtained, and sample colors X (i), Y before correction C _ij (i = 1, 2, 3; j = 1, 2, so as to minimize the color difference between (i), Z (i) (i = 1, 2,..., N). 3) is determined. At that time, as described above, the age of the young person is set to 20 years old, for example, and the age of the older person is set as a variable, and the color difference is minimized for each elderly person age c _ij (i = 1, 2, 3; j = 1, 2, 3) is obtained. By obtaining the correction coefficient based on such a concept, a correction coefficient that cancels the influence of the above-described decrease in lens transmittance and pupil diameter due to aging can be obtained.

Specifically, X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,..., N) and X (i), Y (i), Z ( i) The color difference between (i = 1, 2,..., n) is obtained by converting each into a Lab (or L ^* a ^* b ^* ) color space. That is, the Lab (or L ^* a ^* b ^* ) value of X (i), Y (i), Z (i) (i = 1, 2,..., N) is set to L (i), a ( i), b (i) (i = 1, 2,..., n), and X _a ′ (i), Y _a ′ (i), Z _a ′ (i) (i = 1, 2,. .., N) Lab (or L ^* a ^* b ^* ) values are changed to L ′ (i), a ′ (i), b ′ (i) (i = 1, 2,..., N) In this case, the color difference may be, for example, the following formula (E23).
ΔE (i) = {(L (i) −L ′ (i)) ^ 2+ (a (i) −a ′ (i)) ^ 2+ (b (i) −b ′ (i)) ^ 2} ^ (1/2) (E23)

An evaluation function (objective function) that is minimized in order to obtain c _ij (i = 1, 2, 3; j = 1, 2, 3) is, for example, an average of color differences or a standard deviation (variance). Good. That is, in the case of an average, the evaluation function may be the equation (E24), and in the case of standard deviation, the evaluation function may be the equation (E25). Here, Σ is a sum related to i, and may be a sum from i = 1 to i = n, for example.
J ₁ = (1 / n) ΣΔE (i) (E24)
J ₂ = {(1 / n) Σ (ΔE (i) −J ₁ ) ^ 2} ^ (1/2) (E25)

In the optimization, for example, c _ij (i = 1, 2, 3; j = 1, 2, 3) is set so as to optimize (minimize) one of the evaluation functions of J ₁ and J _2. You may ask for it. Alternatively, c _ij (i = 1, 2, 3; j = 1, 2, 3) is obtained as a solution of a so-called multi-objective optimization problem that optimizes (minimizes) both the evaluation functions of J ₁ and J _2. May be.

J ₁ or J ₂ optimization problem has no solved easily properties such as convexity. Accordingly, for example, a well-known evolution algorithm may be used as a solution that can solve the non-convex optimization problem and the multi-objective optimization problem. The present inventors have a new finding that the multi-objective optimization of J ₁ and J ₂ described above is Pareto optimization (that is, minimization in which minimization of J ₁ and minimization of J ₂ are a trade-off). It has gained. In the present invention, it is not necessary to obtain a strict optimum solution (minimum solution). For example, a solution that converges sufficiently (within a predetermined error) in the iterative calculation may be used.

FIG. 11 shows the above-described color correction method (proposed method) proposed in the present invention and the color correction method (conventional method) disclosed in Patent Document 1 for a sample color (or sample image). It is the figure which applied and showed the color difference obtained as a result. In the proposed method, color correction is performed according to FIG. 9 using the optimum c _ij (i = 1, 2, 3; j = 1, 2, 3) obtained by the above method. On the other hand, in the conventional method, color correction is performed by the method described in Patent Document 1.

  In FIG. 11, color difference 1 is the color difference between the original color (before color correction) and the color after color correction. The color difference 2 is a color difference between the original color and a color obtained by applying the above-mentioned color reproduction for elderly people (FIG. 8) to the color after color correction. (Furthermore, both the color differences 1 and 2 are the sum of i = 1 to i = n in the above formula (E23).)

  As shown in FIG. 11, regarding the color difference 2, the proposed method obtained a smaller color difference than the conventional method at all ages. This result regarding color difference 2 shows that the color correction that makes the proposed method perceive a color closer to the color perceived by young people than the conventional method can be realized for elderly people of any age. . Incidentally, the color difference 1 is also a large color difference in the conventional method. According to the analysis by the present inventor, this numerical value is considered to reflect that color correction is performed only by increasing the numerical values of R, G, and B in the conventional method.

  On the other hand, in the proposed method, the color difference 1 is relatively small, and the color difference 2 is also small. Therefore, if color correction that changes the contribution of RGB in the proposed method is used, the perceptual difference between the elderly and the young can be reduced without significant color correction. The color correction is more appropriate and effective than the above correction.

  In the above embodiment, the display device 1a has been described. However, the projector 1b and the printing device 1c can be similarly implemented. In the case of the projector 1b, it is only necessary to replace the display unit 4 with the projection unit 5 in the above description. In the case of the printing apparatus 1c, R, G, and B may be replaced with magenta (M), yellow (Y), and cyan (S).

Further, in the above-described embodiment, the decrease in color vision due to aging has been dealt with, but the present invention can cope with color vision abnormalities (congenital and acquired). In the case of color blindness, the above description is changed as follows. First, in the case of color blindness, in S10, the user determines that the type of color blindness is a first color blindness (red cone photoreceptor function decline), a second color blindness (green cone photoreceptor decline function), Enter which of the three-color vision abnormalities (decreased function of blue cone photoreceptors). In the discussion of deriving the conversion equation shown in FIG. 8, for example, the miosis rate S is omitted, and the lens transmittance F (λ, A ₂ , A ₁ ) is set to the sensitivity of the retina F (λ ). The sensitivity F (λ) of the retina is obtained for each of the first, second, and third color vision abnormalities. For example, by such a modification, a conversion equation corresponding to FIG. 8 in the case of color vision abnormality is obtained. Other portions may be performed as described above.

  Further, not only the first, second, and third color vision abnormalities, but also the degree of information may be classified and used in, for example, several stages. In that case, in S10, the user inputs any one of the first, second, and third color vision abnormalities and the degree of information, and obtains the conversion formula of FIG. 8 for each degree of retinal sensitivity. By such a modification, the present invention can correct the color so as to perceive a color similar to that of a healthy person (young healthy person) even for a person with abnormal color vision (congenital or acquired).

  The above-described embodiments may be modified and modified based on the spirit described in the claims. For example, in the above-described embodiment, the lens transmittance and the miosis rate are used as the information on the decrease in color vision due to aging. However, the present invention is not limited thereto, and other information related to the decrease in color vision due to aging such as retinal sensitivity is also available. May be used.

1a Display device (color output device)
1b Projector (color output device)
1c Printing device (color output device)
2 Control unit (color correction device)
24 color correction program (program)

Claims (10)

An output means for outputting a color;
An input means for receiving an input indicating that a user who perceives the color output by the output means has a color sense different from that of a young healthy person;
RGB in each of X, Y, and Z of the XYZ color system so that perception by the user of the color output from the output means approaches the perception of a young healthy person according to the input received by the input means Correcting means for correcting the color output from the output means by adjusting the contribution of R, G, B in the color system;
A color output device comprising: The input means is an age input means for receiving information on the age of the user,
The correction means adjusts contributions of R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system according to the age information received by the age input means. The color output device according to 1.   The correction means contributes to R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system so as to cancel the influence of the decrease in the lens transmittance of the user according to age. The color output device according to claim 2, wherein the color output device is adjusted.   The correction means contributes to R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system so as to cancel the influence of the reduction of the pupil diameter of the user according to age. The color output device according to claim 2, wherein the color output device is adjusted. The input means is a type input means for receiving information on the type of color blindness of the user,
The correction unit adjusts the contributions of R, G, and B of the RGB color system in each of X, Y, and Z of the XYZ color system according to the information on the type of color blindness received by the type input unit. The color output device according to claim 1.   The color output apparatus according to claim 1, wherein the output unit is a display unit that displays a color.   The color output apparatus according to claim 1, wherein the output unit is a projection unit that projects a color.   The color output apparatus according to claim 1, wherein the output unit is a printing unit that prints a color. A color correction device provided in a color output device including output means for outputting a color,
An acquisition means for receiving an input received by an input means provided in the color output device and indicating that a user who perceives the color output by the output means has a color vision different from that of a young healthy person;
RGB in each of X, Y, and Z of the XYZ color system so that perception by the user of the color output from the output means approaches the perception of a young healthy person in accordance with the input acquired by the acquisition means Correcting means for correcting the color output from the output means by adjusting the contribution of R, G, B in the color system;
A color correction apparatus comprising: A computer provided in a color output device having output means for outputting a color,
An acquisition means for receiving an input received by an input means provided in the color output device and indicating that a user who perceives the color output by the output means has a color vision different from that of a young healthy person;
RGB in each of X, Y, and Z of the XYZ color system so that perception by the user of the color output from the output means approaches the perception of a young healthy person in accordance with the input acquired by the acquisition means Correcting means for correcting the color output from the output means by adjusting the contribution of R, G, B in the color system;
A program characterized by making it function.

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