JP3434814B2 - Color conversion device and color conversion method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to full-color printing-related equipment such as printers, video printers and scanners, image processing equipment for producing computer graphics images, and data processing used for display devices such as monitors. The present invention relates to a color conversion device and method for performing color conversion processing on image data represented by three colors of red / green / blue in accordance with a device to be used.

[0002]

2. Description of the Related Art Color conversion in printing is an indispensable technique for correcting a deterioration in image quality caused by color mixing and non-linearity of printing due to the fact that ink is not a pure color, and outputting a printed image with good color reproducibility. Is. Also, when displaying an input color signal, a display device such as a monitor outputs (displays) an image having desired color reproducibility in accordance with usage conditions.
Therefore, the color conversion process is performed.

Conventionally, there are two types of color conversion methods in the above case, a table conversion method and a matrix operation method.

The table conversion method uses red, green, and blue (hereinafter,
Image data represented by “R, G, B”) is input, and R, G, B stored in a memory such as a ROM in advance.
Image data or complementary color data of yellow, magenta, and cyan (hereinafter referred to as “Y, M, C”). Since any conversion characteristics can be adopted, color conversion with excellent color reproducibility is performed. There are advantages.

However, with a simple structure in which data is stored for each combination of image data, a large capacity memory of about 400 Mbit is obtained. For example, Japanese Patent Application No. Sho 6 3 - To 227181 discloses (Patent No. 2,105,859) discloses a method of compressing the memory capacity, but still is about 5 Mbit.
Therefore, this method requires a large-capacity memory for each conversion characteristic, which makes it difficult to form an LSI and has a problem that it cannot flexibly deal with changing conditions such as use.

On the other hand, the matrix calculation method is, for example, R,
When obtaining Y, M, and C print data from G and B image data, the following equation (27) is a basic arithmetic equation.

[0007]

[Equation 1]

Here, i = 1 to 3 and j = 1 to 3.

However, the simple linear operation of the equation (27) cannot realize good conversion characteristics due to the non-linearity of the printing.

A method in which the above conversion characteristic is improved is disclosed in the color correction arithmetic unit of Japanese Patent Publication No. 2-30226, and the following matrix arithmetic formula (28) is adopted.

[0011]

[Equation 2]

Here, N is a constant, i = 1 to 3, j = 1 to 1.
It is 10.

The above equation (28) directly uses image data in which an achromatic color component and a color component are mixed, so that mutual interference of calculation occurs. That is, if one coefficient is changed, there is a problem in that it affects not only the component or the hue of interest but also a good conversion characteristic cannot be realized.

Further, Japanese Patent Laid- Open No. 7-170404 (Patent
No. 3128429) color conversion method discloses this solution. FIG. 29 shows the print data C, M, and R, G, B image data in JP-A- 7-170404 .
It is a block circuit diagram showing a color conversion method for converting to Y,
100 is a complement calculator, 101 is an αβ calculator, 102 is a hue data calculator, 103 is a polynomial calculator, 104 is a matrix calculator, 105 is a coefficient generator, and 106 is a combiner.

Next, the operation will be described. Complement device 100
Image data R, G, B are input, and complementary color data Ci, Mi, Yi subjected to 1's complement processing are output. αβ calculator 10
1 outputs the maximum value β and the minimum value α of the complementary color data and the identification code S for specifying each data.

The hue data calculator 102 calculates the complementary color data C.
i, Mi, Yi, maximum value β and minimum value α are input, and r =
β-Ci, g = β-Mi, b = β-Yi and y = Yi
Six pieces of hue data r, g, b, y, m, and c are output by the subtraction process of −α, m = Mi−α, and c = Ci−α. Here, at least two of these six hue data have a property of becoming zero.

The polynomial calculator 103 receives the hue data and the identification code as input, and has two non-zero data Q1, Q2 in r, g, b and two non-zero data P1, P2 in y, m, c. From the polynomial data T1 =
P1 × P2, T3 = Q1 × Q2 and T2 = T1 / (P
1 + P2) and T4 = T2 / (Q1 + Q2) are calculated and output.

The coefficient generator 105 generates an arithmetic coefficient U (Fij) and a fixed coefficient U (Eij) of polynomial data based on the information of the identification signal S. Matrix calculator 104
Inputs hue data y, m, c, polynomial data T1 to T4, and coefficient U, and outputs the calculation result of the following formula (29) as color ink data C1, M1, Y1.

[0019]

[Equation 3]

The synthesizer 106 uses the color ink data C1, M
1, Y1 and α, which is achromatic data, are added, and print data C, M, and Y are output. Therefore, the arithmetic expression for obtaining the print data is the following expression (30).

[0021]

[Equation 4]

Equation (30) discloses a general equation for a pixel set.

Here, FIGS. 30A to 30F are six hues of red (R), blue (G), green (B), yellow (Y), cyan (C), and magenta (M). And hue data y,
It is the figure which showed typically the relationship of m, c, r, g, and b,
Each hue data is associated with three hues. Further, FIGS. 31A to 31F show the above six hues and the multiplication term y ×.
It is the figure which showed typically the relationship of m, rxg, cxy, gxb, mxc, and bxr, and it turns out that each is concerned with a specific hue among six hues. .

Therefore, the six multiplication terms y × m, m × c, c × y, r × g, g × b and b × r in the equation (30).
Are only involved in specific hues of the six hues red, blue, green, yellow, cyan and magenta respectively, that is,
Y × m for red, m × c for blue, c × y for green, r × g for yellow, g × b for cyan, and magenta for magenta. Only b × r is a valid multiplication term.

Further, the six multiplication / division terms y × m / (y + m), m × c / (m + c), and c × y / in the equation (30).
(C + y), r × g / (r + g), g × b / (g +
Regarding b) and b × r / (b + r), only the specific hue among the six hues is involved.

As described above, according to the color conversion method in FIG. 29 described above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue, only the hue of interest is changed to another hue. Can be adjusted without impact.

The multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, it is possible to correct the non-linearity such as the printing with respect to the saturation.

However, even in this color conversion method, the non-linearity of printing with respect to hue remains unsolved. Also, if it is desired to enlarge or reduce the area occupied in the color space of a specific hue according to preference, specifically, magenta to red to
When it is desired to enlarge or reduce the area occupied by red in the color space changing from yellow, the conventional matrix operation type color conversion method cannot satisfy this requirement.

[0029]

When the conventional color conversion method or color conversion device is constituted by a table conversion method using a memory such as a ROM, a large capacity memory is required, and the conversion characteristics can be changed flexibly. However, when the matrix calculation method is used, only the hue of interest can be adjusted, but the degree of change among the six hues of red, blue, green, yellow, cyan, and magenta. However, there is a problem that good conversion characteristics cannot be realized in all color spaces.

The present invention has been made in order to solve the above-mentioned problems, and without using a large capacity memory,
Red-yellow, yellow-green, green-cyan, cyan-
An object of the present invention is to provide a color conversion device and a color conversion method capable of independently correcting regions between six hues of blue, blue to magenta, and magenta to red.

[0031]

A color conversion device according to the present invention is provided with three types of red, green, blue, or cyan, magenta, and yellow .
In the color conversion device for converting the first color data, which is the color data representing the size of each component of the primary color, into the second color data corresponding to the first color data, the first color data is converted into the first color data.
The red, green, and blue of the colors represented by removing the achromatic components
Indicates the size of each color component of cyan, magenta, and yellow
Hue data for calculating hue data r, g, b, c, m, y
A data calculating means, provided for each of the color data of red, yellow, green, cyan, blue, and coefficient generating means for outputting a coefficient for designating a specific area in between adjacent hue of magenta, the Multiply the hue data by the above coefficient
Using the multiplication value , it becomes maximum in the above specific area,
And operand generation means for generating an effective calculation term region in between the hue including the particular region, and a matrix coefficient generating means for outputting a predetermined matrix coefficients given to the calculating section, the upper Symbol operation Given for the terms and the terms above
And a matrix calculation means for outputting the second color data by performing a matrix calculation including multiplication with a matrix coefficient .

Further, the color conversion method according to the present invention is
Green, blue, or each of the three primary colors of cyan, magenta, and yellow
In the color conversion method of converting the first color data including the color data representing the size of the component into the second color data corresponding to the first color data , the first color data is represented by the first color data.
Red, green, blue, and shea, which are the colors obtained by removing the achromatic components from the colors
Hue representing the size of each color component of magenta, magenta, and yellow
Data r, g, b, c, m, y are calculated and the hue data
Given for each data, and outputs red, yellow, green, cyan, blue, coefficients for designating a particular region in between adjacent hue of magenta, the coefficient on the hue data
Using a multiplication value obtained by multiplying the above becomes maximum in a specific area, to generate an operand to produce an effective calculation terms in the region in between the hue including the specific region, versus above operation term
Outputs a predetermined matrix coefficients given by the matrix coefficients given for the calculation terms and the arithmetic term
By performing a matrix operation including multiplication of
The color data of is output.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. Embodiment 1. 1 is a block diagram showing an example of the configuration of a color conversion device according to a first embodiment of the present invention. In the figure, 1 is the maximum value β of the input image data R, G, B
And a minimum value α, and an αβ calculator that generates and outputs an identification code that identifies each data, and 2 is image data R, G, B
And from the output from the αβ calculator 1, the hue data r, g,
Hue data calculator for calculating b, y, m, c, 3 is a polynomial calculator, 4 is a matrix calculator, 5 is a coefficient generator, 6
Is a synthesizer.

FIG. 2 is a block diagram showing an example of the configuration of the polynomial calculator 3 described above. In the figure, 11 is a zero remover that removes zero data from the input hue data, 12a and 12b are multipliers, 13a and 13b are adders, 14a and 14b are dividers, and 15 is the αβ calculator. 1
, 16a and 16b are operation coefficient generators for generating and outputting operation coefficients based on the identification code from
An arithmetic unit that multiplies the input data with the arithmetic coefficient indicated by the output from 5, and 17 and 18 are minimum value selectors that select and output the minimum value of the input data.

Next, the operation will be described. The input image data R, G, B (Ri, Gi, Bi) is sent to the αβ calculator 1 and the hue data calculator 2, and the αβ calculator 1
Calculates and outputs the maximum value β and the minimum value α of the input image data Ri, Gi, Bi, and also generates and outputs the identification code S1 that specifies each data. Hue data calculator 2
Is the image data Ri, Gi, Bi and the maximum value β and minimum value α output from the αβ calculator 1, and r = R
i-α, g = Gi-α, b = Bi-α and y = β-B
i, m = β-Gi, c = β-Ri is subtracted, and 6
Two hue data r, g, b, y, m, c are output.

At this time, the maximum value β and the minimum value α calculated by the αβ calculator 1 are β = MAX (Ri, G
i, Bi), α = MIN (Ri, Gi, Bi),
The six hue data r, g, b, y, m, and c calculated by the hue data calculator 2 are r = Ri-α and g = Gi.
-Α, b = Bi-α and y = β-Bi, m = β-G
Since i, c = β-Ri is obtained by the subtraction process, at least two of these six hue data are included.
One has the property of becoming zero. For example, the maximum value β is Ri,
When the minimum value α is Gi (β = Ri, α = Gi),
From the above subtraction processing, g = 0 and c = 0, and
When the maximum value β is Ri and the minimum value α is Bi (β = R
i, α = Bi), b = 0 and c = 0. That is, the maximum and minimum combinations of Ri, Gi, and Bi result in one of r, g, and b, and one of y, m, and c, that is, two values in total.

Therefore, the αβ calculator 1 generates and outputs the identification code S1 for identifying the data that becomes zero out of the six hue data. This identification code S1
Are six types of identification codes S that specify the data depending on whether the maximum value β or the minimum value α is Ri, Gi, or Bi.
1 can be generated, and FIG. 3 shows the identification codes S1 and Ri,
It is a figure which shows the maximum value (beta) in Gi, Bi, the minimum value (alpha), and the relationship of the hue data used as zero. It should be noted that the value of the identification code S1 in the figure shows an example thereof, and the value is not limited to this and may be another value.

Next, the six pieces of hue data r, g, b and y, m, c which are the outputs from the hue data calculator 2 are sent to the polynomial calculation means 3, and regarding r, g, b. It is also sent to the matrix calculator 4. The identification code S1 output from the αβ calculator 1 is also input to the polynomial calculator 3, and two non-zero data Q in r, g, and b are input.
1, Q2 and two non-zero data P in y, m, c
The operation is performed by selecting 1 or P2, and this operation will be described with reference to FIG.

In the polynomial calculator 3, the hue data from the hue data calculator 2 and the identification code S1 from the αβ calculator
Is input to the zero remover 11, and in the zero remover 11,
Based on the identification code S1, two non-zero data Q1, Q2 in r, g, b and two non-zero data P1, P2 in y, m, c are output. Here, the data Q1, Q2, P1 and P2 output from the zero remover 11 are
From the hue data excluding the data that becomes zero, Q1 ≧ Q2,
The data Q1, Q2, P1, and P2 are output as P1 ≧ P2. That is, as shown in FIG. 4, Q1, Q2, P
1 and P2 are determined and are output. For example, from FIGS.
When the identification code S1 = 0, r, b to Q1, Q2
, P1 and P2 are obtained from y and m. At this time, since the maximum value β = Ri and the minimum value α = Gi, r
(= Β-α) ≧ b (= Bi-α), m (= β-α) ≧ y
(= Β-Bi), Q1 = r, Q2 = b, P1 =
Output as m and P2 = y. Note that, as in FIG. 3 above,
The value of the identification code S1 in FIG. 4 shows an example thereof, and the value is not limited to this and may be another value.

The output data Q1 and Q2 from the zero remover 11 are input to the multiplier 12a, and the product T3 =
Q1 × Q2 is calculated and output, and the output data P1 and P2 from the zero remover 11 are input to the multiplier 12b,
Calculate and output T1 = P1 × P2. Adder 13a and 1
3b outputs sums Q1 + Q2 and P1 + P2, respectively. The divider 14a receives T3 from the multiplier 12a and Q1 + Q2 from the adder 13a, and T4 = T3 /
The quotient of (Q1 + Q2) is output, and the divider 14b receives T1 from the multiplier 12b and P1 + P2 from the adder 13b and outputs the quotient of T2 = T1 / (P1 + P2).

The identification code S1 from the αβ calculating means 1 is input to the arithmetic coefficient generator 15, and the arithmetic units 16a and 16a are provided.
b, a signal indicating the operation coefficients aq and ap for multiplying the data P2 and Q2 is generated based on the identification code S1, and the operation coefficient aq is supplied to the operation unit 16a.
The calculation coefficient ap is output to b. Note that this calculation coefficient a
For q and ap, the coefficients corresponding to the respective hue data Q2 and P2 are generated according to the identification code S1, and from FIG. 4, six types of calculation coefficients aq and ap are generated for the identification code S1. The data Q2 from the zero remover 11 is input to the arithmetic unit 16a, and the multiplication a by the arithmetic coefficient aq from the arithmetic coefficient generator 15 and the data Q2.
q × Q2, and send the output to the minimum value selector 17,
In the arithmetic unit 16b, the data P2 from the zero remover 11
Is input, the multiplication coefficient ap from the calculation coefficient generator 15 is multiplied by the data P2, and the output is sent to the minimum value selector 17.

In the minimum value selector 17, the minimum value t6 = min (aq × Q) of the outputs from the arithmetic units 16a and 16b.
2, ap × P2) is selected and output to the minimum value selector 18. The output data Q1 from the zero remover 11 is also input to the minimum value selector 18, and Q1 and t6 = min (a
q * Q2, ap * P2) minimum value T5 = min (Q1,
min (aq × Q2, ap × P2)) is output. As described above, the above-mentioned polynomial data T1, T2, T3, T4, T
5 is the output of the polynomial calculator 3. The output of the polynomial calculator 3 is sent to the matrix calculator 4 as a calculation term .

On the other hand, the coefficient generator 5 of FIG.
Based on 1, the calculation coefficient U (Fij) and the fixed coefficient U (Eij) of the polynomial data are generated and sent to the matrix calculator 4. The matrix calculator 4 is the hue data calculator 2
To the hue data r, g, b, the polynomial data T1 to T5 from the polynomial calculator 3, and the coefficient U from the coefficient generator 5, and the calculation result of the following equation (19) is the image data R1,
Output as G1 and B1.

[0044]

[Equation 5]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 5.

FIG. 5 is a block diagram showing a partial structural example of the matrix calculator 4 and shows a case where R1 is calculated and output. In the figure, 20
a to 20f are multipliers, and 21a to 21e are adders.

Next, the operation of FIG. 5 will be described. Multiplier 20
a to 20f are the hue data r, the polynomial data T1 to T5 from the polynomial calculator 3, and the coefficient U (E from the coefficient generator 5).
ij) and U (Fij) are input, and the product of each is output. The adders 21a and 21b include the multipliers 20b to 20b.
The product that is the output of 20e is input, the input data is added, and the sum is output. The adder 21c is the adder 21a,
21b adds the data, and the adder 21d adds the data to the adder 2
The output from 1c and the output from the multiplier 20f are added. Then, the adder 21e adds the output of the adder 21d and the output of the multiplier 20a, and outputs the sum as image data R1. In the configuration example of FIG. 5, the hue data r
If g is replaced with g or b, the image data G1 and B1 can be calculated.

Although it is a limb, the coefficients (Eij) and (Fi
For j), the coefficients corresponding to the respective hue data r, g, b are used. That is, if three configurations shown in FIG. 5 are used in parallel for r, g, and b, high-speed matrix calculation becomes possible.

The combiner 6 receives the image data R1, G1, B1 from the matrix calculator 4 and the minimum value α representing the achromatic color data output from the αβ calculator 1,
Addition is performed and image data R, G and B are output. Therefore, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. 1 is the following expression (1).

[0050]

[Equation 6]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m) and aq1 to aq6 and ap1 to ap6 are
These are calculation coefficients generated by the calculation coefficient generator 15 in FIG.

It should be noted that the difference in the number of operation terms in the equation (1) and the number of operation terms in FIG. 1 discloses an operation method for each pixel except for data in which the operation terms in FIG. 1 are zero. , (1) discloses a general formula for a pixel set. That is, the polynomial data of the equation (1) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data.

The combination of valid data changes depending on the image data of the pixel of interest, and all polynomial data are valid in all image data.

FIGS. 6A to 6F schematically show the relationship between six hues and hue data y, m, c, r, g, and b, and each hue data has three hues. Involved in hue.

FIGS. 7A to 7F schematically show the relationship between the six hues and the multiplication terms y × m, r × g, c × y, g × b, m × c, and b × r. It can be seen that each multiplication term is a quadratic term associated with a particular hue. For example,
With W as a constant, for red, r = W and g = b = 0, so that y = m = W and c = 0. Therefore, y × m =
W × W, and the other five terms are all zero. That is, for red, only y × m is a valid quadratic term. Similarly, for green, c × y, for blue, m × c, for cyan, g × b,
Only b × r is effective for magenta and r × g is effective for yellow.

The above equations (19) and (1) are the same for each hue.
Includes only valid first-order multiplication and division terms. This multiplication / division term is r × g / (r + g), g × b / (g + b), b
Xr / (b + r), yxm / (y + m), mxc / (m
+ C) and c * y / (c + y), which are the first-order terms. For example, with W as a constant, for red, r =
W, g = b = 0, y = m = W, c = 0. At this time, y × m / (y + m) = W / 2, and the other five terms are all zero. Therefore, for red, y × m /
Only (y + m) becomes a valid first-order term. Similarly, c × y / (c + y) for green, m × c / (m + c) for blue, g × b / (g + b) for cyan, and b × r / (b for magenta.
+ R) and yellow, r × g / (r + g) is the only effective primary term. Here, if the numerator and denominator are zero, 1
The next term shall be zero.

Next, the difference between the first-order term and the second-order term will be described. As described above, for red, if W is a constant, y × m = W × W, and all other multiplication terms are zero. Here, since the constant W represents the magnitudes of the hue signals y and m, the magnitude of the constant W represents the vividness of the color in the pixel,
Depends on saturation. Since y × m = W × W, the multiplication term y
Xm is a quadratic function with respect to saturation. The other multiplication terms are also quadratic functions with respect to saturation in the hues in which they are effective. Therefore, the influence of each multiplication term on the color reproduction increases quadratically as the saturation increases. That is, the multiplication term is a quadratic term that plays the role of a quadratic correction term for saturation in color reproduction.

On the other hand, if W is a constant for red, then y
× m / (y + m) = W / 2, and all other multiplication and division terms become zero. Here, the magnitude of the constant W depends on the vividness and saturation of the color in the pixel. y × m / (y + m) =
Since it is W / 2, the multiplication / division term y × m / (y + m) is a linear function with respect to the saturation. The other multiplication / division terms are also linear functions in terms of saturation in the hues in which they are effective. Therefore, the effect of each multiplication and division term on the color reproduction is a linear function with respect to the saturation. That is,
The multiplication / division term is a primary term that plays the role of a primary correction term for saturation in color reproduction.

FIGS. 8A to 8F show six hues and the primary operation terms min (r, hry), m using the comparison data.
in (g, hgy), min (g, hgc), min
(B, hbc), min (b, hbm), min (r,
hrm) is schematically shown, and hry = min (aq1 × in equation (5) and equation (1) above).
g, ap1 × m), hrm = min (aq2 × b, ap
2 × y), hgy = min (aq3 × r, ap3 ×
c), hgc = min (aq4 × b, ap4 × y), h
bm = min (aq5 × r, ap5 × c), hbc = m
Calculation coefficient aq in (aq6 × g, ap6 × m)
The case where the values of 1 to aq6 and ap1 to ap6 are 1 is shown. From each of FIG. 8, the change of the intermediate area between the six hues of the primary calculation terms using each comparison data is red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red. You can see that they are involved in. That is, for red to yellow, b = c = 0 and min (r, hry) = min (r, min
All other five terms except (g, m)) are zero. Therefore, min (r, hry) = min (r, min (g,
m)) is the only valid primary operation term, and similarly, min (g, hgy) for yellow to green and mi for green to cyan.
n (g, hgc), min (b, hb) for cyan to blue
c), only min (b, hbm) for blue to magenta, and min (r, hrm) for magenta to red are effective primary operation terms.

FIGS. 9A to 9F show hry, hrm, hgy, hgc, hb in the equations (19) and (1).
Calculation coefficients aq1 to aq6 and ap in m and hbc
1 to ap6 are changed, six hues and the relations of the primary operation terms using the comparison data are schematically shown. In the case shown by broken lines a1 to a6 in the figure, aq1 to aq
6 is a value larger than ap1 to ap6, and in the case of broken lines b1 to b6, ap1 to ap6 are a
The characteristic is shown when the value is larger than q1 to aq6.

That is, for red to yellow, min
(R, hry) = min (r, min (aq1 × g, a
p1 × m)) is the only effective primary operation term, but if the ratio of aq1 to ap1 is 2: 1, the peak value is related to red, as indicated by the broken line a1 in FIG. 9 (A). Can be used as a calculation term that is effective for a region close to red between the hues of red and yellow. On the other hand, for example, aq1
And the ratio of ap1 is 1: 2, the broken line b in FIG.
The relation is as shown in FIG. 1, the peak value is an operation term relating to yellow, and it can be an operation term effective in a region close to yellow between the hues of red and yellow. Similarly, aq3 and ap3 at min (g, hgy) for yellow to green, and min (g, hg) at green to cyan.
aq4 and ap4 in c) are min for cyan to blue
Aq6 and ap6 in (b, hbc) and aq5 and ap5 in min (b, hbm) for blue to magenta.
For magenta to red, a at min (r, hrm)
By changing q2 and ap2, the effective area can be changed even in the areas between the respective hues.

FIGS. 10A and 10B show the relationship between the six hues and the inter-hue areas and the valid calculation terms.
Therefore, in the coefficient generator 5, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues can also be corrected. You can Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues. these
The coefficient takes into consideration the characteristics of the device to which the color conversion process is applied.
The target color reproducibility can be obtained with the device.
It is appropriately set by those skilled in the art.

Here, an example of the coefficient in the coefficient generator 5 in the first embodiment according to FIG. 1 will be described. The following equation (17) is used to calculate the coefficient U (Ei generated in the coefficient generator 5).
j) shows an example.

[0064]

[Equation 7]

In the above case, if the coefficients of the coefficient U (Fij) are all zero, the color conversion is not performed. Further, in the following expression (18), in the coefficient of the coefficient U (Fij), all the coefficients related to the quadratic operation term which is the multiplication term are set to 0, and the multiplication and division term which is the primary operation term and the operation term by the comparison data are set. Related coefficients are, for example, Ar1 to Ar3 and Ay1 to Ay.
3, Ag1-Ag3, Ac1-Ac3, Ab1-Ab
3, Am1 to Am3, and Ary1 to Ary3, Ag
y1-Agy3, Agc1-Agc3, Abc1-Ab
c3, Abm1 to Abm3, and Arm1 to Arm3 are shown.

[0066]

[Equation 8]

In the above, since the correction is performed by the multiplication and division term which is the primary operation term and the operation term based on the comparison data, only the hue or the area between the hues can be adjusted linearly and the hue or the hue between the hues to be changed can be adjusted. If a coefficient related to the primary calculation term related to the area is set and the other coefficients are set to zero, only the hue or the area between the hues can be adjusted. For example, if the coefficients Ar1 to Ar3 relating to m × y / (m + y) relating to red are set, it is necessary to set min (r, hry) to change the hue of red and the ratio between the hues of red and yellow. The coefficients Ary1 to Ary3 will be used.

In the polynomial calculator 3, hry =
min (aq1 × g, ap1 × m), hrm = min
(Aq2 × b, ap2 × y), hgy = min (aq3
Xr, ap3xc), hgc = min (aq4xb, a
p4 × y), hbm = min (aq5 × r, ap5 ×
c), if the values of the arithmetic coefficients aq1 to aq6 and ap1 to ap6 in hbc = min (aq6 × g, ap6 × m) are changed by integer values of 1, 2, 4, 8, ... Multiplication can be performed by bit shifting at 16b.

From the above, the coefficient of the coefficient U (Fij) is independently corrected by changing the coefficient relating to the multiplication term and the multiplication / division term relating to a specific hue, and the degree of change between the above six hues. Can also be corrected. Further, the above multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, It is also possible to correct non-linearity such as printing for saturation. Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

In the first embodiment, the hue data r, g, b and y, m, c, the maximum value β, and the minimum value α are calculated based on the input image data R, G, B. After obtaining the operation term related to the hue and performing the matrix operation, the image data R,
Although the case where G and B are obtained has been described, after obtaining the output image data R, G and B, the R, G and B are replaced with the complementary color data C,
It may be converted into M and Y, and the same effect as described above is obtained.

In the first embodiment, the case where the processing of the configuration of FIG. 1 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the first embodiment is achieved.

Embodiment 2. In the first embodiment, the hue data r, g, b and y, m, c and the maximum value β and the minimum value α are calculated on the basis of the input image data R, G, B, and the operation terms relating to each hue are calculated. In the above description, the case where the image data R, G, B are obtained after the matrix calculation has been described. Can be configured to perform color conversion.

FIG. 11 is a block diagram showing an example of the configuration of a color conversion device and a color conversion method according to the second embodiment of the present invention. In the figure, 3 to 6 are the same as those in FIG. 1 of the first embodiment, and 10 is a complementer and 1
b is an αβ calculator that generates an identification code for specifying the maximum value β and the minimum value α of the complementary color data and the hue data, 2b
Is the hue data r, g, b, y, m, c from the complementary color data C, M, Y from the complementer 10 and the output from the αβ calculator 1.
Is a hue data calculator for calculating.

Next, the operation will be described. The complementer 10 receives the image data R, G, and B as inputs and outputs complementary color data Ci, Mi, and Yi that have been subjected to 1's complement processing. The αβ calculator 1b outputs the maximum value β and the minimum value α of the complementary color data and the identification code S1 for specifying each hue data.

The hue data calculator 2b uses the complementary color data C
i, Mi, Yi and the maximum value β and the minimum value α from the αβ calculator 1b are input, and r = β-Ci, g = β-Mi, b
= Β-Yi and y = Yi-α, m = Mi-α, c = C
By the subtraction process of i-α, six hue data r, g,
b, y, m, c are output. Here, these six hue data have a property that at least two of them are zero, and the identification code S1 output from the αβ calculator 1b.
Specifies the data that is zero among the six hue data, and the maximum value β and the minimum value α are Ci, Mi, Yi.
There are six types of identification codes that specify the data depending on which one of them. Since the relationship between the data that becomes zero out of the six hue data and the identification code is the same as that described in the first embodiment, detailed description thereof will be omitted.

Next, the six pieces of hue data r, g, b and y, m, c output from the hue data calculator 2b are sent to the polynomial calculation means 3, and regarding c, m, y, It is also sent to the matrix calculator 4. The identification code S1 output from the αβ calculator 1b is also input to the polynomial calculator 3, and two data Q1 and Q2 that are not zero in r, g, and b, and nonzero in y, m, and c. The operation is performed by selecting the two data P1 and P2, but since this operation is the same as the operation of FIG. 2 in the first embodiment, the detailed description thereof will be omitted.

The output of the polynomial calculator 3 is sent to the matrix calculator 4, and the coefficient generator 5 calculates the coefficient U (Fij) of the polynomial data and the fixed coefficient U (Eij) based on the identification code S1. Is generated and sent to the matrix calculator 4. The matrix calculator 4 includes the hue data c, m, y from the hue data calculator 2b, the polynomial data T1 to T5 from the polynomial calculator 3, and the coefficient U from the coefficient generator 5.
Is input, and the calculation result of the following equation (20) is output as image data C1, M1, and Y1.

[0078]

[Equation 9]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 5.

In the operation of the matrix calculator 4, the input hue data in FIG. 5 in the first embodiment is c (or m, y), and C1 (or M1, Y1) is calculated and output. Since the same operation is performed in this case, detailed description thereof will be omitted.

The synthesizer 6 receives the complementary color data C1, M1, Y1 from the matrix calculator 4 and the minimum value α representing the achromatic color data output from the αβ calculator 1b, performs addition, and adds an image. The data C, M and Y are output. Therefore, the arithmetic expression for obtaining the image data C, M, and Y that has been color-converted by the color conversion method of FIG. 11 is the following expression (2).

[0082]

[Equation 10]

In (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m), and aq1 to aq6 and ap1 to ap6 are arithmetic coefficients generated by the arithmetic coefficient generator 15 in FIG.

It should be noted that the difference in the number of the operation terms in the equation (2) and the number of the operation terms in FIG. 11 discloses the operation method for each pixel except the data in which the operation terms in FIG. 11 are zero. , (2) is a point that discloses a general formula for a pixel set. That is, the polynomial data of the equation (2) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data.

The combination of valid data changes depending on the image data of the pixel of interest, and all polynomial data are valid in all image data.

The arithmetic terms of the polynomial arithmetic unit of the above equation (2) are the same as the arithmetic terms of the equation (1) in the first embodiment, and therefore, the six hues and the inter-hue regions and the effective arithmetic terms. Is the same as that shown in FIGS. 10 (a) and 10 (b). Therefore, as in the first embodiment, in the coefficient generator 5, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between the hues is changed, only the hue of interest can be adjusted, and the change between the hues can be changed. The degree of can also be corrected. Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

Here, as an example of the coefficient in the coefficient generator 5 in the second embodiment, as in the case of the first embodiment, the coefficient U (Eij) by the equation (17) is obtained, and the coefficient U ( When all the coefficients of Fij) are set to zero, the color conversion is not performed. Further, the coefficient U (F
In the coefficient of ij), all the coefficients related to the quadratic operation term that is a multiplication term are set to 0, and correction is performed using the coefficients related to the multiplication and division term that is the first order operation term and the operation term based on the comparison data. If only the hue or the area between the hues can be adjusted, and the coefficient relating to the primary calculation term relating to the hue or the area between the hues to be changed is determined and the other coefficients are set to zero,
Only the hue or the area between the hues can be adjusted.

From the above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue, red,
Only the hues of interest in the six hues of blue, green, yellow, cyan, and magenta can be adjusted without affecting the other hues, and further, the primary calculation term using the comparison data of the hue data By changing the coefficient, red-yellow, yellow-green, green-cyan, cyan-blue,
The areas between the six hues of blue to magenta and magenta to red can be corrected independently to correct the degree of change between the above six hues. Further, the above multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, It is also possible to correct non-linearity such as printing for saturation. Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

In the second embodiment, the case where the processing of the configuration of FIG. 11 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the second embodiment is obtained.

Embodiment 3. In the first embodiment, it is assumed that a partial configuration example of the matrix calculator 4 is a block diagram shown in FIG. 5, and as shown in the equation (1), the hue data, each calculation term, and the achromatic color data R, Although the minimum value α of G and B is added to output the image data R, G and B, as shown in FIG. 12, the coefficient generator generates a coefficient for the minimum value α which is achromatic data. Accordingly, the achromatic component can be adjusted.

FIG. 12 is a block diagram showing an example of the configuration of a color conversion device and a color conversion method according to the third embodiment of the present invention. In the figure, 1 to 3 are the same as those in FIG. 1 of the first embodiment, 4b is a matrix calculator, and 5b is a coefficient generator.

Next, the operation will be described. Αβ from input data
The operation of obtaining the maximum value β, the minimum value α and the identification code S1 from the calculator 1, calculating the six hue data from the hue data calculator 2, and obtaining the calculation term in the polynomial calculator 3 is the same as in the first embodiment. Therefore, detailed description thereof will be omitted.

The coefficient generator 5b shown in FIG.
Based on the above, a calculation coefficient U (Fij) and a fixed coefficient U (Eij) of the polynomial data are generated and sent to the matrix calculation unit 4b. The matrix calculator 4b has the hue data r, g, b from the hue data calculator 2, polynomial data T1 to T5 from the polynomial calculator 3, and the minimum value α from the αβ calculator 1.
The coefficient U from the coefficient generator 5b and the coefficient U are input to perform a calculation. The calculation formula (21) below is used to adjust the achromatic component.

[0094]

[Equation 11]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 6.

Here, FIG. 13 is a block diagram showing a partial configuration example of the matrix calculator 4b. In FIG. 13, 20a to 20f and 21a to 21e are the matrix calculator 4 in the first embodiment. 22 is a multiplier for inputting the minimum value α indicating the achromatic component from the αβ calculator 1 in FIG. 1 and the coefficient U from the coefficient generator 5b, and 23 is an adder. is there.

Next, the operation of FIG. 13 will be described. Multiplier 2
0a to 20f are the hue data r, the polynomial data T1 to T5 from the polynomial calculator 3, and the coefficient U from the coefficient generator 5.
(Eij) and U (Fij) are input, the respective products are output, and the respective products and sums are added in the adders 21a to 21e. The operation is performed by the matrix calculator 4 in the first embodiment. Is the same as the operation in. The multiplier 22 includes a minimum value α of R, G, B data corresponding to the achromatic component from the αβ calculator 1 and the coefficient generator 5b.
From which the coefficient U (Fij) is input and multiplication is performed, and the product is output to the adder 23.
The output from 1e is added and the sum is output as the output R of the image data R. In the configuration example of FIG. 13, if the hue data r is replaced with g or b, the image data G,
B can be calculated.

Here, the coefficients (Eij) and (Fij) are
A coefficient corresponding to each hue data r, g, b is used, and if three configurations in FIG. 13 are used in parallel for r, g, b, high-speed matrix calculation becomes possible.

As described above, the matrix calculator 4b calculates each coefficient and the minimum value α, which is achromatic color data, by a coefficient, and adds it to the hue data to obtain the image data R, G,
The arithmetic expression for outputting B and obtaining the image data at this time is
It becomes the following formula (3).

[0100]

[Equation 12]

Here, in (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

It should be noted that the difference in the number of operation terms of equation (3) and the number of operation terms in FIG. 12 is that the operation terms in the polynomial data operation unit of FIG. 12 are zero, as in the case of the first embodiment. While the calculation method for each pixel excluding data is disclosed, the expression (3) discloses a general expression for a pixel set. That is, the polynomial data of the formula (3) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data.

The combination of valid data changes depending on the image data of the pixel of interest, and all polynomial data are valid in all image data.

Here, if all the coefficients relating to the minimum value α are 1, the achromatic color data is not converted and has the same value as the achromatic color data in the input data. Then, by changing the coefficient in the matrix calculation, reddish black, bluish black, or the like can be selected, and the achromatic component can be adjusted.

From the above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue and the primary operation terms relating to the inter-hue region, red, blue, green,
The coefficient relating to the minimum value α, which is achromatic color data, is used to adjust only the hues of interest in the six hues of yellow, cyan, and magenta and the six hue areas, without affecting other hues. By changing, it is possible to adjust only the achromatic component without affecting the hue component, for example, standard black, reddish black,
It is possible to select bluish black or the like.

In the third embodiment, the case where the matrix-calculated image data R, G, B are obtained has been described. However, after the output image data R, G, B are obtained, R, G, B are obtained.
B may be converted into complementary color data C, M, and Y, and if the coefficient in the matrix calculation can be changed with respect to each hue and inter-hue area and the minimum value α that is achromatic color data, the same effect as above can be obtained.

Further, it is needless to say that in the third embodiment as well as the first embodiment, the same processing can be performed by the software in the color conversion device, as in the third embodiment. Produce an effect.

Fourth Embodiment In the second embodiment, as shown in the equation (2), the hue data is added to each operation term and the minimum value α which is the achromatic color data. However, as shown in FIG. It is also possible to adjust the achromatic component by generating a coefficient for the minimum value α which is the data.

FIG. 14 is a block diagram showing an example of the configuration of a color conversion device and a color conversion method according to the fourth embodiment of the present invention. In the figure, 10, 1b, 2b and 3 are the same as those in FIG. 11 of the second embodiment, and 4b and 5b are the same as those in FIG. 12 of the third embodiment.

Next, the operation will be described. Image data R, G,
B is input to the complement calculator 10, 1's complement-processed complementary color data Ci, Mi, Yi are output, the αβ calculator 1b obtains the maximum value β, the minimum value α and the identification code S1, and the hue data calculator 2b calculates The operation of calculating the six hue data and obtaining the calculation term in the polynomial calculator 3 is the same as in Embodiment
Since it is the same as the processing for the complementary color data C, M, and Y, detailed description thereof will be omitted.

The coefficient generator 5b shown in FIG.
Based on the above, a calculation coefficient U (Fij) and a fixed coefficient U (Eij) of the polynomial data are generated and sent to the matrix calculation unit 4b. The matrix calculator 4b receives the hue data c, m, y from the hue data calculator 2b, the polynomial data T1 to T5 from the polynomial calculator 3, the minimum value α from the αβ calculator 1b, and the coefficient generator 5b. The calculation is performed by using the coefficient U as an input. The calculation formula (22) below is used to adjust the achromatic component.

[0112]

[Equation 13]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 6.

In the operation of the matrix calculator 4b, in FIG. 13 in the third embodiment, the input hue data is c (or m, y) and C (or M, Y) is calculated and output. Since the same operation is performed in this case, detailed description thereof will be omitted.

From the above, the matrix calculator 4b calculates each coefficient and the minimum value α, which is achromatic color data, by a coefficient and adds it to the hue data to obtain complementary color data C, M,
The arithmetic expression for outputting Y and obtaining the image data at this time is
It becomes the following formula (4).

[0116]

[Equation 14]

In (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

It should be noted that the difference in the number of operation terms of the equation (4) and the number of operation terms in FIG. 14 is that the operation term in the polynomial data operation unit of FIG. 14 is zero, as in the case of the second embodiment. While the calculation method for each pixel excluding data is disclosed, the formula (4) discloses a general formula for a pixel set. That is, the polynomial data of the equation (4) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data.

The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

Here, if all the coefficients relating to the minimum value α are 1, the achromatic color data is not converted and has the same value as the achromatic color data in the input data. Then, by changing the coefficient in the matrix calculation, reddish black, bluish black, or the like can be selected, and the achromatic component can be adjusted.

From the above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue and the primary operation terms relating to the inter-hue region, red, blue, green,
The coefficient relating to the minimum value α, which is achromatic color data, is used to adjust only the hues of interest in the six hues of yellow, cyan, and magenta and the six hue areas, without affecting other hues. By changing, it is possible to adjust only the achromatic component without affecting the hue component, for example, standard black, reddish black,
It is possible to select bluish black or the like.

Further, it is needless to say that similar to the above-described embodiment, the above-described processing can be performed by the software in the color conversion device also in the fourth embodiment, and the same effect as in the above-mentioned third embodiment is obtained. Play.

Embodiment 5. FIG. In the first to fourth embodiments, it is assumed that one example of the configuration of the polynomial calculator 3 is a block diagram shown in FIG. 2, and it is configured to calculate and output the polynomial data represented by the formulas (1) to (4) However, it can be configured to calculate polynomial data as shown in FIG.

FIG. 15 is a block diagram showing another example of the configuration of the polynomial calculator 3. In the figure, 11 to 17 are the same as those of the polynomial calculator in FIG.
Reference numeral 18b is a minimum value selector for selecting and outputting the minimum value of the input data.

Next, the operation of FIG. 15 will be described. The operation of the zero remover 11, the multipliers 12a and 12b, and the adder 1
3a, 13b, T14 = Q1 by the dividers 14a, 14b
× Q2, T4 = T3 / (Q1 + Q2), T1 = P1 × P
2, T2 = T1 / (P1 + P2) is output, and t6 = min (aq × Q2, ap × P) by the arithmetic coefficient generator 15, arithmetic units 16a and 16b, and minimum value selector 17.
The operation up to the output of 2) is the same as the operation in FIG. 2 in the above-described embodiment, and thus detailed description thereof will be omitted.

Output from the minimum value selector 17 t6 = min
(Aq × Q2, ap × P2) is output to the minimum value selector 18b, the output data P1 from the zero remover 11 is also input to the minimum value selector 18b, and P1 and t6 = m
The minimum value of in (aq × Q2, ap × P2) T5 ′ = mi
n ( P 1, min (aq × Q2, ap × P2)) is output. Therefore, the polynomial data T1, T2, T3, T
4, T5 'become the output of the polynomial calculator in FIG. 15, and the output of this polynomial calculator is sent to the matrix calculator 4 or 4b.

As described above, according to the polynomial arithmetic unit 3 in FIG. 15, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. It becomes the formula 5).

[0128]

[Equation 15]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m), and aq1 to aq6 and ap1 to ap6 are calculation coefficients generated by the calculation coefficient generator 15 in FIG.

It should be noted that the difference in the number of operation terms in the equation (5) and the number of operation terms in FIG. 15 discloses the operation method for each pixel except the data in which the operation terms in FIG. 15 are zero. , Equation (5) discloses a general equation for a pixel set, that is, the polynomial data of equation (5) can reduce 18 pieces of data to 5 pieces of effective data for one pixel. The reduction is achieved by skillfully utilizing the nature of the hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

Here, in FIGS. 16A to 16F, six hues and the primary operation term min using the above comparison data.
(Y, hry), min (y, hgy), min (c,
hgc), min (c, hbc), min (m, hb
m) and min (m, hrm) are schematically shown. The broken lines a1 to a6 and b1 to b in the figure
When 6 is shown, hry, hrm, hgy, hgc, h
Calculation coefficients aq1 to aq6 and a in bm and hbc
The characteristics when p1 to ap6 are changed are shown, and the solid line shows the case where the values of the arithmetic coefficients aq1 to aq6 and ap1 to ap6 are 1. From each of FIGS. 16A and 16B, the change in the intermediate region between the six hues of red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red is the primary calculation item using each comparison data. You can see that they are involved in. That is, for red to yellow, b = c = 0, and all five terms except min (y, hry) are zero. Therefore, min (y, h
Only ry) is a valid primary operation term, and similarly, min (y, hgy) for yellow to green and mi for green to cyan.
n (c, hgc), min (c, hb) for cyan to blue
c), min (m, hbm) for blue to magenta, and min (m, hrm) for magenta to red are the only effective primary operation terms.

FIGS. 17A and 17B show the relationship between the six hues and the inter-hue regions and the valid arithmetic terms.
Therefore, in the coefficient generator, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues can be corrected. it can. Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

From the above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue, red,
Only the hues of interest in the six hues of blue, green, yellow, cyan, and magenta can be adjusted without affecting the other hues, and further, the primary calculation term using the comparison data of the hue data By changing the coefficient, red-yellow, yellow-green, green-cyan, cyan-blue,
The areas between the six hues of blue to magenta and magenta to red can be corrected independently to correct the degree of change between the above six hues. Further, the above multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, It is also possible to correct non-linearity such as printing for saturation. Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

In the fifth embodiment, the case where the processing of the configuration of FIG. 15 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the fifth embodiment is obtained.

Sixth Embodiment Further, according to the polynomial arithmetic unit 3 in FIG. 15 in the above-mentioned Embodiment 5, the arithmetic expression for obtaining the image data C, M, Y color-converted by the color conversion method in FIG. (6)
It becomes an expression.

[0136]

[Equation 16]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m), and aq1 to aq6 and ap1 to ap6 are calculation coefficients generated by the calculation coefficient generator 15 in FIG.

It should be noted that the difference in the number of operation terms in the equation (6) and the number of operation terms in FIG. 15 discloses the operation method for each pixel except the data in which the operation terms in FIG. 15 are zero. , (6) discloses a general formula for a pixel set. That is, the polynomial data of the equation (6) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

The operation terms by the polynomial operator of the above equation (6) are the same as the operation terms of the equation (5) in the fifth embodiment, and therefore, the six hues and the inter-hue regions and the valid operation terms are 17 is the same as that shown in FIGS. 17 (a) and 17 (b). Therefore, as in the fifth embodiment, if the coefficient relating to the calculation term effective in the hue to be adjusted or the area between hues is changed in the coefficient generator, only the hue of interest can be adjusted, and the change in hue The degree can also be corrected. Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

From the above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue, red,
Only the hues of interest in the six hues of blue, green, yellow, cyan, and magenta can be adjusted without affecting the other hues, and further, the primary calculation term using the comparison data of the hue data By changing the coefficient, red-yellow, yellow-green, green-cyan, cyan-blue,
The areas between the six hues of blue to magenta and magenta to red can be corrected independently to correct the degree of change between the above six hues. Further, the above multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, It is also possible to correct non-linearity such as printing for saturation. Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

Seventh Embodiment Further, according to the polynomial arithmetic unit 3 of FIG. 15 in the above-mentioned Embodiment 5, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. 12 in the above-mentioned Embodiment 3 is as follows. (7)
It becomes an expression.

[0142]

[Equation 17]

In (Eij), i = 1 to 3 and j =
1-3, (Fij) i = 1-3, j = 1-19.

It should be noted that the difference in the number of operation terms in the equation (7) and the number of operation terms in FIG. 15 discloses the operation method for each pixel except the data in which the operation term in the polynomial data operation unit in FIG. 15 is zero. On the other hand, the expression (7) discloses a general expression for a pixel set. That is, the polynomial data of the equation (7) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

As described above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to a specific hue and the primary operation terms relating to the inter-hue region, red, blue, green,
The coefficient relating to the minimum value α, which is achromatic color data, is used to adjust only the hues of interest in the six hues of yellow, cyan, and magenta and the six hue areas, without affecting other hues. By changing, it is possible to adjust only the achromatic component without affecting the hue component, for example, standard black, reddish black,
It is possible to select bluish black or the like.

Eighth Embodiment Further, according to the polynomial arithmetic unit 3 of FIG. 15 in the above-mentioned Embodiment 5, the arithmetic expression for obtaining the complementary color data C, M, Y which has been color-converted by the color conversion method of FIG. 14 in the above-mentioned Embodiment 3 is as follows: (8)
It becomes an expression.

[0147]

[Equation 18]

Here, in (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

It should be noted that the difference between the number of operation terms in the equation (8) and the number of operation terms in FIG. 15 is to disclose the operation method for each pixel except the data in which the operation term in the polynomial data operation unit in FIG. 15 is zero. On the other hand, the expression (8) discloses the general expression for the pixel set. That is, the polynomial data of the equation (8) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

As described above, by changing the coefficients relating to the multiplication term and the multiplication / division term relating to the specific hue and the primary operation terms relating to the inter-hue region, red, blue, green,
The coefficient relating to the minimum value α, which is achromatic color data, is used to adjust only the hues of interest in the six hues of yellow, cyan, and magenta and the six hue areas, without affecting other hues. By changing, it is possible to adjust only the achromatic component without affecting the hue component, for example, standard black, reddish black,
It is possible to select bluish black or the like.

Ninth Embodiment FIG. 18 is a block diagram showing another configuration example of the color conversion device and the color conversion method according to the ninth embodiment of the present invention. In the figure, 1, 2 and 6
Is the same as the reference numeral in FIG. 1 in the first embodiment. 3b is a polynomial calculator, 4c is a matrix calculator,
5c is a coefficient generator.

FIG. 19 is a block diagram showing a configuration example of the polynomial calculator 3b. In the figure, 11,
Reference numerals 12a and 12b, 15 to 18 are the same as those in the polynomial calculator 3 of FIG. 2 in the first embodiment. Reference numerals 30a and 30b are minimum value selectors for selecting and outputting the minimum value of the input data.

Next, the operation will be described. Α in FIG.
The operations of the β calculator 1 and the hue data calculator 2 are the same as the operations in the above-described first embodiment, and thus detailed description thereof will be omitted. In the polynomial calculator 3b, based on the identification code S1 output from the αβ calculator 1, r, g,
Two non-zero data Q1, Q2 in b and y, m,
Two pieces of data P1 and P2 which are not zero in c are selected and the operation is performed. This operation will be described with reference to FIG.

In the polynomial calculator 3b, the input hue data r, g, b and y, m, c and the identification code S1 are sent to the zero remover 11, and based on the identification signal S1, r, g
Two non-zero data Q1, Q2 and y in g, b,
Two non-zero data P1 and P2 in m and c are output. The output data Q1, Q2 from the zero remover 11 is input to the multiplier 12a, the product T3 = Q1 × Q2 is calculated and output, and the output data P1 from the zero remover 11 is output to the multiplier 12b. P2 is input and T1 = P1 × P2
Is calculated and output. The operation up to this point is the same as in the first embodiment.
2 and the operation coefficient generator 15 and the operation units 16a and 16b and the minimum value selector 1
The operations in 7 and 18 are also the same as those in the first embodiment, and therefore detailed description thereof will be omitted.

The zero remover 1 is connected to the minimum value selector 30a.
Output data Q1 and Q2 from 1 are input, and the minimum value T7
= Min (Q1, Q2) is selected and output, and output data P from the zero remover 11 is output to the minimum value selector 30b.
1, P2 are input, and the minimum value T6 = min (P1, P2
Select 2) and output. The above polynomial data T1, T
3, T5, T6, and T7 become the output of the polynomial calculator 3b, and the output of this polynomial calculator 3b is sent to the matrix calculator 4c.

Then, the coefficient generator 5c of FIG. 18 uses the identification code S1 to calculate the operation coefficient U (Fi
j) and a fixed coefficient U (Eij) are generated and sent to the matrix calculator 4c. The matrix calculator 4c has hue data r, g, b from the hue data calculator 2 and polynomial data T1, T3, T5, T6, T from the polynomial calculator 3b.
7 and the coefficient U from the coefficient generator 5 are input, and the following (2
The calculation result of equation 3) is output as image data R, G, and B.

[0157]

[Formula 19]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 5.

FIG. 20 is a block diagram showing a partial configuration example of the matrix calculator 4c, showing the case where R1 is calculated and output. In the figure, 20a to 20f and 21a to 21e are shown in FIG.
Shows the same as in.

Next, the operation of FIG. 20 will be described. Multiplier 2
0a to 20f are input with the hue data r, the polynomial data T1, T3, T5, T6, T7 from the polynomial calculator 3b and the coefficients U (Eij) and U (Fij) from the coefficient generator 5c. Is output. Adders 21a, 2
1b receives the product output from each of the multipliers 20b to 20e as an input, adds the input data, and outputs the sum. The adder 21c adds the data from the adders 21a and 21b,
The adder 21d outputs the output from the adder 21c and the multiplier 20f.
Add the products that are the output of. Then, the adder 21e adds the output of the adder 21d and the output of the multiplier 20a, and outputs the sum as image data R1. In the configuration example of FIG. 20, if the hue data r is replaced with g or b,
The image data G1 and B1 can be calculated.

Although it is an extraordinary thing, the coefficients (Eij) and (Fi
For j), the coefficients corresponding to the respective hue data r, g, b are used. That is, if three configurations of FIG. 20 are used in parallel for r, g, and b, high-speed matrix calculation becomes possible.

The combiner 6 receives the image data R1, G1, B1 from the matrix calculator 4c and the minimum value α representing the achromatic color data output from the αβ calculator 1 and adds them to obtain an image. The data R, G, B are output. Therefore, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. 18 is the following expression (9).

[0163]

[Equation 20]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18.

The difference between the equation (9) and the number of operation terms in FIG. 18 discloses an operation method for each pixel except for data in which the operation term in the polynomial operation unit 3b in FIG. 18 is zero. On the other hand, the expression (9) discloses a general expression for a pixel set. That is, the polynomial data of the equation (9) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. Also, the combination of valid data is
It changes depending on the image data of the pixel of interest, and all polynomial data is valid in all image data.

21A to 21F, the calculation terms min (y, m), min (r,
g), min (c, y), min (g, b), min
The relationship between (m, c) and min (b, r) is schematically shown, and each operation term has the property of a first-order term. For example,
With W as a constant, for red, r = W and g = b = 0, so that y = m = W and c = 0. At this time, min
(Y, m) = W, and the other five terms are all zero. Here, the magnitude of the constant W is the vividness of the color in the pixel,
Since it depends on the saturation and min (y, m) = W, mi
n (y, m) is a linear function with respect to saturation. Therefore, for red, only min (y, m) is valid 1
It will be the next section. Similarly, the calculation terms based on other comparison data
In the hues in which they are effective, they become first-order functions in terms of saturation, and min (c, y) for green, min (m, c) for blue, min (g, b) for cyan, and magenta for magenta. Is min (b, r), yellow is min (r,
Only g) is the valid first order term.

22 (a) and 22 (b) are the same as FIG.
For the arithmetic term obtained from the polynomial arithmetic unit 3b in
The relationship between the six hues and the inter-hue areas and the valid calculation terms is shown. Therefore, in the coefficient generator 5c, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues can also be corrected. You can Also,
By changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3b, it is possible to change the area in which the calculation term in the inter-hue area is valid without affecting other hues.

Here, as an example of the coefficient in the coefficient generator 5 in the ninth embodiment, as in the case of the first embodiment, the coefficient U (Eij) by the equation (17) is obtained, and the coefficient U ( When all the coefficients of Fij) are set to zero, the color conversion is not performed. Further, the coefficient U (F
In the coefficient of ij), all the coefficients related to the quadratic operation term that is a multiplication term are set to 0, and correction is performed using the coefficients related to the multiplication and division term that is the first order operation term and the operation term based on the comparison data. If only the hue or the area between the hues can be adjusted, and the coefficient relating to the primary calculation term relating to the hue or the area between the hues to be changed is determined and the other coefficients are set to zero,
Only the hue or the area between the hues can be adjusted.

The first-order multiplication / division terms T4 = Q1 × Q2 / (Q1 + Q2) and T2 = in the first to eighth embodiments.
P1 × P2 / (P1 + P2) and the first-order term T7 = min (Q1, Q2) according to the comparison data in the ninth embodiment,
T6 = min (P1, P2) is related to the same hue, but in the case of the operation item based on the comparison data in the ninth embodiment, it becomes effective for a specific hue only by selecting the minimum value of each hue data. The first-order term can be obtained, and the processing can be simplified and the processing speed can be increased as compared with the case where the operation term is obtained by the multiplication and division.

From the above, by changing the coefficients related to the primary operation term using the multiplication term relating to a specific hue and the comparison data of the hue data, red, blue, green, yellow,
It is possible to adjust only the hue of interest in the six hues of cyan and magenta without affecting other hues,
Furthermore, by changing the coefficients related to each of the primary calculation terms related to the inter-hue region, red to yellow, yellow to
It is also possible to independently correct the regions between the six hues of green, green to cyan, cyan to blue, blue to magenta, and magenta to red, and also to correct the degree of change between the above six hues. Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

In the ninth embodiment, the hue data r, g, b and y, m, c, the maximum value β, and the minimum value α are calculated based on the input image data R, G, B, respectively. After obtaining the operation term related to the hue and performing the matrix operation, the image data R,
Although the case where G and B are obtained has been described, after obtaining the output image data R, G and B, the R, G and B are replaced with the complementary color data C,
It may be converted into M and Y, and the six hue data and the maximum value β and the minimum value α are obtained, and each operation term as shown in FIG. 22 can be calculated, and the coefficient in the matrix operation is calculated for each hue and between hues. If it can be changed with respect to the region, the same effect as described above can be obtained.

In the ninth embodiment, the case where the processing of the configuration of FIG. 18 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the ninth embodiment is obtained.

Embodiment 10. FIG. In the ninth embodiment,
Based on the input image data R, G, B, the hue data r, g,
The description has been made assuming that b, y, m, and c and the maximum value β and the minimum value α are calculated to obtain the operation terms related to each hue, and the image data R, G, and B are obtained after the matrix operation. It is also possible to convert R, G, B into complementary color data C, M, Y, and then perform color conversion with the input as complementary color data C, M, Y.

FIG. 23 is a block diagram showing an example of the configuration of a color conversion device and a color conversion method according to the tenth embodiment of the present invention. In the figure, 1b, 2b, 10 and 6 are the same as those in FIG.
c is the same as that in FIG. 18 of the ninth embodiment.

Next, the operation will be described. The complementer 10 receives the image data R, G, and B as inputs and outputs complementary color data Ci, Mi, and Yi that have been subjected to 1's complement processing. The αβ calculator 1b outputs the maximum value β and the minimum value α of the complementary color data and the identification code S1 for specifying each hue data.

The hue data calculator 2b uses the complementary color data C
i, Mi, Yi and the maximum value β and the minimum value α from the αβ calculator 1b are input, and r = β-Ci, g = β-Mi, b
= Β-Yi and y = Yi-α, m = Mi-α, c = C
By the subtraction process of i-α, six hue data r, g,
b, y, m, c are output. Here, these six hue data have a property that at least two of them are zero, and the identification code S1 output from the αβ calculator 1b.
Specifies the data that is zero among the six hue data, and the maximum value β and the minimum value α are Ci, Mi, Yi.
There are six types of identification codes that specify the data depending on which one of them. Since the relationship between the data that becomes zero out of the six hue data and the identification code is the same as that described in the first embodiment, detailed description thereof will be omitted.

Next, the six pieces of hue data r, g, b and y, m, c which are the outputs from the hue data calculator 2b are sent to the polynomial calculation means 3b, and regarding c, m, y, It is also sent to the matrix calculator 4c. The identification code S output from the αβ calculator 1b is input to the polynomial calculator 3b.
1 is also input, and two non-zero data Q1, Q2 in r, g, b and two non-zero data P1, P2 in y, m, c are selected and the operation is performed. Since this operation is the same as the operation of FIG. 19 in the ninth embodiment, detailed description thereof will be omitted.

The output of the polynomial arithmetic unit 3b is sent to the matrix arithmetic unit 4c, and the coefficient generator 5c calculates the arithmetic coefficient U (Fi) of the polynomial data based on the identification code S1.
j) and a fixed coefficient U (Eij) are generated and sent to the matrix calculator 4c. The matrix calculator 4c calculates the hue data c, m, y from the hue data calculator 2b and the polynomial data T1, T3, T5 and T6, T7 from the polynomial calculator 3b, and the coefficient U from the coefficient generator 5c. As input,
The calculation result of the following equation (24) is used as the image data C1, M1, Y
Output as 1.

[0179]

[Equation 21]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 5.

In the operation of the matrix calculator 4c, the hue data to be input is c (or m, y) in FIG. 20 in the ninth embodiment, and C1 (or M1, Y1) is calculated and output. Since the same operation is performed in this case, detailed description thereof will be omitted.

The synthesizer 6 includes the complementary color data C1, M1, Y1 from the matrix calculator 4c and the αβ calculator 1b.
The minimum value α indicating the achromatic color data, which is the output from, is input, addition is performed, and the image data C, M, and Y are output. Therefore, the arithmetic expression for obtaining the image data C, M and Y color-converted by the color conversion method of FIG. 23 is the following expression (10).

[0183]

[Equation 22]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18.

Note that the difference in the number of operation terms in the equation (10) and the number of operation terms in FIG. 23 discloses the operation method for each pixel except the data in which the operation terms in FIG. 23 are zero. , (10) discloses a general formula for a pixel set. That is, the polynomial data of the equation (10) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. Also, the combination of valid data is
It changes depending on the image data of the pixel of interest, and all polynomial data is valid in all image data.

The arithmetic terms of the above polynomial arithmetic unit of the equation (10) are the same as the arithmetic terms of the equation (9) in the ninth embodiment, and therefore, the six hues and the inter-hue regions and the effective arithmetic terms are used. 22 is the same as that shown in FIGS. 22 (a) and 22 (b). Therefore, as in the ninth embodiment,
In the coefficient generator 5c, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues can also be corrected. . Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3b, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

Here, as an example of the coefficient in the coefficient generator 5 in the tenth embodiment, as in the case of the first embodiment, the coefficient U (Eij) by the equation (17) is obtained, and the coefficient U ( When all the coefficients of Fij) are set to zero, the color conversion is not performed. Further, the coefficient U shown in the equation (18)
In the coefficient of (Fij), all the coefficients related to the quadratic calculation term that is a multiplication term are set to 0, and correction is performed by the coefficients related to the multiplication / division term that is a primary calculation term and the calculation term based on the comparison data. The hue or the area between the hues can be adjusted, and the hue or the area between the hues to be changed
If the coefficients relating to the next calculation term are determined and the other coefficients are set to zero, only the hue or the area between the hues can be adjusted.

As described above, by changing the coefficients relating to the multiplication term relating to a specific hue and the primary operation term using the comparison data of the hue data, red, blue, green, yellow,
It is possible to adjust only the hue of interest in the six hues of cyan and magenta without affecting other hues,
Further, by changing the coefficient relating to the primary calculation item using the comparison data of the hue data, six hues of red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red are obtained. It is possible to correct the areas between the six hues by independently correcting the areas between them. Further, the above multiplication term is a quadratic operation for saturation, and the multiplication / division term is a primary operation for saturation. Therefore, by using both the multiplication term and the multiplication / division term, It is also possible to correct non-linearity such as printing for saturation.
Therefore, it is possible to obtain a color conversion device or a color conversion method that can flexibly change the conversion characteristics and does not require a large capacity memory.

In the tenth embodiment, the case where the processing of the configuration of FIG. 23 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the tenth embodiment is obtained.

Eleventh Embodiment In the ninth embodiment, a partial configuration example of the matrix calculator 4c is shown in FIG.
The block diagram shown in FIG. 24 is used, and the configuration is as shown in equation (9). However, as shown in FIG. 24, the coefficient generator generates a coefficient for the minimum value α, which is the achromatic color data. Can also be configured to adjust.

FIG. 24 is a block diagram showing an example of the arrangement of a color conversion device and a color conversion method according to the eleventh embodiment of the present invention. In the figure, reference numerals 1, 2, 3b are the same as those in FIG. 18 of the ninth embodiment, 4d is a matrix calculator, and 5d is a coefficient generator.

Next, the operation will be described. From input data αβ
The maximum value β, the minimum value α, and the identification code S1 are calculated by the calculator 1.
And the calculation of the six hue data by the hue data calculator 2 and the calculation term in the polynomial calculator 3b are the same as those in the ninth embodiment, and the detailed description thereof will be omitted.

The coefficient generator 5d shown in FIG.
Based on the above, a calculation coefficient U (Fij) and a fixed coefficient U (Eij) of the polynomial data are generated and sent to the matrix calculator 4d. The matrix calculator 4d has hue data r, g, b from the hue data calculator 2 and polynomial data T1, T3, T5, T6, T7 and α from the polynomial calculator 3b.
The minimum value α from the β calculator 1 and the coefficient U from the coefficient generator 5d are input, and the calculation is performed. The calculation formula uses the following formula (25) to adjust the achromatic component.

[0194]

[Equation 23]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 6.

FIG. 25 is a block diagram showing a partial configuration example of the matrix calculator 4d. In FIG. 25, 20a to 20f and 21a to 21e are the matrix calculator 4c in the ninth embodiment. The same, 2
Reference numerals 2 and 23 are the same as those in the matrix calculator 4b of FIG. 13 in the third embodiment.

Next, the operation of FIG. 25 will be described. Multiplier 2
0a to 20f are the hue data r, the polynomial data T1, T3, T5 and T6 and T7 from the polynomial calculator 3b, and the coefficients U (Eij) and U (Fi) from the coefficient generator 5d.
j) as an input, each product is output, and the adder 21a
21e, the respective products and sums are added, but the operation is the same as the operation in the matrix calculators 4 and 4c in the embodiment. In the multiplier 22, R, G corresponding to the achromatic color component from the αβ calculator 1,
The minimum value α of B data and the coefficient U (F
ij) is input, multiplication is performed, the product is output to the adder 23, and the product is added to the output from the adder 21e, and the sum is output as the output R of the image data R. Note that, in the configuration example of FIG.
Alternatively, the image data G and B can be calculated by substituting b.

Here, the coefficients (Eij) and (Fij) are
A coefficient corresponding to each hue data r, g, b is used, and if three configurations in FIG. 25 are used in parallel for r, g, b, high-speed matrix calculation becomes possible.

From the above, the matrix computing unit 4d performs computation by each coefficient with respect to the minimum value α which is the achromatic color data and adds it to the hue data to obtain the image data R, G,
The arithmetic expression for outputting B and obtaining the image data at this time is
It becomes the following formula (11).

[0200]

[Equation 24]

In (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

Note that the difference in the number of operation terms in equation (11) and the number of operation terms in FIG. 24 is the same as in the first embodiment.
While the calculation method for each pixel excluding the data in which the calculation term in the polynomial data calculator in FIG. 24 is zero is disclosed, the expression (11) discloses a general expression for a pixel set. . That is, the polynomial data of equation (11) is
For one pixel, 19 pieces of data can be reduced to 6 pieces of effective data, and this reduction is achieved by skillfully utilizing the property of hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

If all the coefficients relating to the minimum value α are set to 1, the achromatic color data is not converted and has the same value as the achromatic color data in the input data. Then, by changing the coefficient in the matrix calculation, reddish black, bluish black, or the like can be selected, and the achromatic component can be adjusted.

As described above, by changing the coefficients of the primary operation term using the multiplication term relating to a specific hue and the comparison data of the hue data, and the primary operation term relating to the inter-hue region, , Blue, green, yellow, cyan,
Only the hues of interest in the six hues of magenta and the inter-hue area can be adjusted without affecting other hues. By changing the coefficient relating to the minimum value α, which is achromatic color data. It is possible to adjust only the achromatic component without affecting the hue component, and it is possible to select standard black, reddish black, bluish black, or the like.

In the eleventh embodiment, the case has been described in which the image data R, G, B after matrix calculation are obtained, but after the output image data R, G, B are obtained, R, G, B are obtained.
G and B may be converted into complementary color data C, M and Y, and if the coefficient in the matrix calculation can be changed with respect to each hue and inter-hue area and the minimum value α which is achromatic color data, the same effect as above can be obtained. Play.

As in the case of the eleventh embodiment, needless to say, the same processing as the above-described processing can be performed by software in the color conversion apparatus. Play.

Twelfth Embodiment In the tenth embodiment, (1
As shown in the equation (0), the hue data and each operation term and the minimum value α which is the achromatic color data are added. However, as shown in FIG. 26, the coefficient generator generates the minimum value α which is the achromatic color data. It can also be configured to adjust the achromatic component by generating a coefficient for.

FIG. 26 is a block diagram showing an example of the arrangement of a color conversion device and a color conversion method according to the twelfth embodiment of the present invention. In the figure, 10, 1b, 2b and 3b are the same as those in FIG. 23 of the tenth embodiment, and 4d and 5d are the same as those in FIG. 24 of the eleventh embodiment.

Next, the operation will be described. Image data R, G,
B is input to the complement calculator 10, 1's complement-processed complementary color data Ci, Mi, Yi are output, the αβ calculator 1b obtains the maximum value β, the minimum value α and the identification code S1, and the hue data calculator 2b calculates The operation of calculating the six hue data and obtaining the calculation term in the polynomial calculator 3b is the same as the processing in the case of the complementary color data C, M, and Y of the tenth embodiment, and thus the detailed description thereof is omitted.

The coefficient generator 5d shown in FIG.
Based on the above, a calculation coefficient U (Fij) and a fixed coefficient U (Eij) of the polynomial data are generated and sent to the matrix calculator 4d. The matrix calculator 4d includes the hue data c, m, y from the hue data calculator 2b and the polynomial data T1, T3, T5 to T7 from the polynomial calculator 3 and the αβ calculator 1.
The minimum value α from b and the coefficient U from the coefficient generator 5d are input, and the calculation is performed. The calculation formula uses the following formula (26) to adjust the achromatic component.

[0211]

[Equation 25]

In (Eij), i = 1 to 3 and j = 1.
˜3 and (Fij), i = 1 to 3 and j = 1 to 6.

The operation in the matrix calculator 4d is the same as that in FIG. 25 of the eleventh embodiment, where the input hue data is c (or m, y) and C (or M, Y) is calculated and output. Since the same operation is performed in this case, detailed description thereof will be omitted.

As described above, the matrix calculator 4d calculates each coefficient and the minimum value α, which is achromatic color data, by a coefficient, and adds the calculated value to the hue data to obtain complementary color data C, M,
The arithmetic expression for outputting Y and obtaining the image data at this time is
It becomes the following formula (12).

[0215]

[Equation 26]

Here, in (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

The difference in the number of operation terms of the equation (12) and the number of operation terms in FIG. 26 is the same as in the case of the above-described embodiment, when the data in the polynomial data operation unit of FIG. The calculation method for each pixel except for is disclosed, whereas the expression (12) discloses a general expression for a pixel set. That is, the polynomial data of equation (12) is 1
For each pixel, 19 pieces of data can be reduced to 6 pieces of effective data, and this reduction is achieved by skillfully utilizing the property of hue data. The combination of valid data changes according to the image data of the pixel of interest, and all polynomial data are valid in all image data.

Here, if all the coefficients relating to the minimum value α are 1, the achromatic color data is not converted and has the same value as the achromatic color data in the input data. Then, by changing the coefficient in the matrix calculation, reddish black, bluish black, or the like can be selected, and the achromatic component can be adjusted.

As described above, by changing the coefficients of the primary operation term using the multiplication term relating to the specific hue and the comparison data of the hue data and the primary operation term relating to the inter-hue region, , Blue, green, yellow, cyan,
Only the hues of interest in the six hues of magenta and the inter-hue area can be adjusted without affecting other hues. By changing the coefficient relating to the minimum value α, which is achromatic color data. It is possible to adjust only the achromatic component without affecting the hue component, and it is possible to select standard black, reddish black, bluish black, or the like.

Further, it is needless to say that similar to the above-described embodiment, the above-described processing can be performed by the software in the color conversion device in the twelfth embodiment as well. Play.

Thirteenth Embodiment In the ninth to twelfth embodiments, it is assumed that one example of the configuration of the polynomial calculator 3b is a block diagram shown in FIG. However, it can be configured to calculate polynomial data as shown in FIG.

FIG. 27 is a block diagram showing another example of the configuration of the polynomial calculator 3b. In the figure, 11, 12a,
12b, 15 to 17 and 30a, 30b are the same as those of the polynomial calculator in FIG. 19 of the ninth embodiment, and 18b is the same minimum value selection as in FIG. 15 of the fifth embodiment. It is a vessel.

Next, the operation of FIG. 27 will be described. The operation of the zero remover 11 and the multipliers 12a and 12b cause T3
= Q1 × Q2, T1 = P1 × P2 is output, and T7 = min (Q1, Q by the minimum value selectors 30a and 30b).
2), the operation of outputting T6 = min (P1, P2), and t6 = min (aq × Q2, ap by the arithmetic coefficient generator 15, the arithmetic units 16a and 16b, and the minimum value selector 17).
The operation up to the output of × P2) is the same as the operation in FIG. 19 in the above-described embodiment, and thus detailed description thereof will be omitted.

Output from minimum value selector 17 t6 = min
(Aq × Q2, ap × P2) is output to the minimum value selector 18b, the output data P1 from the zero remover 11 is also input to the minimum value selector 18b, and P1 and t6 = m
The minimum value T5 ′ = mi of in (aq × Q2, ap × P2)
n (P1, min (aq × Q2, ap × P2)) is output. Therefore, the polynomial data T1, T3, T6, T
7 and T5 'become the output of the polynomial calculator in FIG. 27, and the output of this polynomial calculator is the matrix calculator 4
sent to c or 4d.

As described above, according to the polynomial arithmetic unit 3b shown in FIG. 27, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. Equation 13) is obtained.

[0226]

[Equation 27]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m), and aq1 to aq6 and ap1 to ap6 are arithmetic coefficients generated by the arithmetic coefficient generator 15 in FIG.

It should be noted that the difference in the number of operation terms in the equation (13) and the number of operation terms in FIG. 27 discloses the operation method for each pixel except the data in which the operation terms in FIG. 27 are zero. , Eq. (13) discloses a general formula for a pixel set, that is, the polynomial data of Eq. (13) can reduce 18 data to 5 effective data for one pixel. The reduction is achieved by skillfully utilizing the nature of the hue data. Also, the combination of valid data is
It changes depending on the image data of the pixel of interest, and all polynomial data is valid in all image data.

Here, six hues and the primary operation terms min (y, hry), min (y,
hgy), min (c, hgc), min (c, hb
The relationship between c), min (m, hbm), and min (m, hrm) is shown in FIG.
It is the same as the case shown in (F), and the primary operation terms using each comparison data are six hues of red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red. It can be seen that it is involved in changes in the intermediate region of.
That is, for red to yellow, min (y, hr
Only y) is a valid primary operation term, and similarly, min (y, hgy) for yellow to green and min for green to cyan.
(C, hgc), min (c, hb) for cyan to blue
c), min (m, hbm) for blue to magenta, and min (m, hrm) for magenta to red are the only effective primary operation terms.

FIGS. 28 (a) and 28 (b) show the relationship between the six hues and the inter-hue regions and the valid calculation terms.
Therefore, in the coefficient generator, if the coefficient relating to the calculation term effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues can be corrected. it can. Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3b, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

As described above, by changing the coefficients relating to the multiplication term relating to a specific hue and the primary calculation term using the comparison data of the hue data, red, blue, green, yellow,
It is possible to adjust only the hue of interest in the six hues of cyan and magenta without affecting other hues,
Further, by changing the coefficient relating to the primary calculation item using the comparison data of the hue data, six hues of red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red are obtained. It is possible to correct the areas between the six hues by independently correcting the areas between them. Therefore,
It is possible to obtain a color conversion device or color conversion method that can flexibly change conversion characteristics and does not require a large capacity memory.

In the thirteenth embodiment, the case where the processing of the configuration of FIG. 27 is performed by hardware has been described, but it goes without saying that the same processing can be performed by software in the color conversion device. The same effect as that of the thirteenth embodiment is obtained.

Fourteenth Embodiment In addition, the first embodiment
According to the polynomial arithmetic unit 3b in FIG. 27 in FIG. 3, the arithmetic expression for obtaining the image data C, M, Y color-converted by the color conversion method in FIG. .

[0234]

[Equation 28]

Here, in (Eij), i = 1 to 3, j =
1 to 3 and (Fij), i = 1 to 3 and j = 1 to 18, and hry = min (aq1 × g, ap1 × m), hr
m = min (aq2 × b, ap2 × y), hgy = mi
n (aq3 × r, ap3 × c), hgc = min (aq
4 × b, ap4 × y), hbm = min (aq5 × r,
ap5 × c), hbc = min (aq6 × g, ap6 ×
m), and aq1 to aq6 and ap1 to ap6 are arithmetic coefficients generated by the arithmetic coefficient generator 15 in FIG.

Note that the difference in the number of operation terms in the equation (14) and the number of operation terms in FIG. 27 discloses the operation method for each pixel except the data in which the operation terms in FIG. 27 are zero. , (14) discloses a general formula for a pixel set. That is, the polynomial data of the equation (14) can reduce 18 pieces of data to 5 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. Also, the combination of valid data is
It changes depending on the image data of the pixel of interest, and all polynomial data is valid in all image data.

The arithmetic terms of the equation (14) by the polynomial arithmetic unit are the same as the arithmetic terms of the equation (13) in the thirteenth embodiment, and therefore, six hues and inter-hue regions and effective arithmetic terms. 28 is the same as that shown in FIGS. 28 (a) and 28 (b). Therefore, the first embodiment
As in the case of 3, in the coefficient generator, if the coefficient relating to the calculation term that is effective for the hue to be adjusted or the area between hues is changed, only the hue of interest can be adjusted, and the degree of change between hues is also corrected. be able to. Further, by changing the coefficient in the calculation coefficient generator 15 in the polynomial calculator 3b, the area in which the calculation term in the inter-hue area is valid can be changed without affecting other hues.

From the above, by changing the coefficients relating to the multiplication term relating to a specific hue and the calculation term using the comparison data by the hue data, red, blue, green, yellow,
It is possible to adjust only the hue of interest in the six hues of cyan and magenta without affecting other hues,
Further, by changing the coefficient relating to the primary calculation item using the comparison data of the hue data, six hues of red to yellow, yellow to green, green to cyan, cyan to blue, blue to magenta, and magenta to red are obtained. It is possible to correct the areas between the six hues by independently correcting the areas between them. Therefore,
It is possible to obtain a color conversion device or color conversion method that can flexibly change conversion characteristics and does not require a large capacity memory.

Fifteenth Embodiment In addition, the first embodiment
According to the polynomial arithmetic unit 3b in FIG. 27 in FIG. 3, the arithmetic expression for obtaining the image data R, G, B color-converted by the color conversion method of FIG. 24 in the eleventh embodiment is the following Expression (15). .

[0240]

[Equation 29]

Here, in (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

The difference in the number of operation terms of the equation (15) and the number of operation terms in FIG. 27 is that the operation method for each pixel except the data in which the operation term in the polynomial data operation unit of FIG. 27 is zero is disclosed. On the other hand, the expression (15) discloses the general expression for the pixel set. That is, the polynomial data of the equation (15) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. Also, the combination of effective data changes depending on the image data of the pixel of interest,
All polynomial data are valid for all image data.

From the above, red and blue can be obtained by changing the coefficients relating to the multiplication term relating to a specific hue and the comparison term using the comparison data based on the hue data, and the primary computation term relating to the inter-hue region. , Green, yellow, cyan,
Only the hues of interest in the six hues of magenta and the inter-hue area can be adjusted without affecting other hues. By changing the coefficient relating to the minimum value α, which is achromatic color data. It is possible to adjust only the achromatic component without affecting the hue component, and it is possible to select standard black, reddish black, bluish black, or the like.

Sixteenth Embodiment In addition, the first embodiment
According to the polynomial arithmetic unit 3b of FIG. 27 in FIG. 3, the arithmetic expression for obtaining the complementary color data C, M, Y which is color-converted by the color conversion method of FIG. .

[0245]

[Equation 30]

Here, in (Eij), i = 1 to 3, j =
1-3, (Fij) i = 1-3, j = 1-19.

The difference in the number of operation terms of the equation (16) and the number of operation terms in FIG. 27 is that the operation method for each pixel except the data in which the operation term in the polynomial data operation unit of FIG. 27 is zero is disclosed. On the other hand, the expression (16) discloses the general expression for the pixel set. That is, the polynomial data of the equation (16) can reduce 19 pieces of data to 6 pieces of effective data for one pixel, and this reduction is achieved by skillfully utilizing the property of the hue data. Also, the combination of effective data changes depending on the image data of the pixel of interest,
All polynomial data are valid for all image data.

From the above, red and blue can be obtained by changing the coefficients associated with the multiplication term relating to a specific hue and the comparison term using the comparison data based on the hue data, and the primary computation term relating to the inter-hue region. , Green, yellow, cyan,
Only the hues of interest in the six hues of magenta and the inter-hue area can be adjusted without affecting other hues. By changing the coefficient relating to the minimum value α, which is achromatic color data. It is possible to adjust only the achromatic color component without affecting the hue component, and it is possible to select, for example, standard black, reddish black, bluish black, or the like.

[0249]

As described above, the color conversion device and the color conversion method according to the present invention are applicable to the achromatic component from the color represented by the first color data.
Except red, green, blue, cyan, magenta, yellow
Hue data r, g, b, c, representing the magnitude of each color component of
m and y are calculated and given for each of the above hue data.
Is, red, yellow, green, cyan, blue, coefficients for designating a particular region in between adjacent hue of magenta, upper
Using a multiplication value obtained by multiplying the serial hue data, it becomes maximum in the specific area, to generate an operand to produce an effective calculation terms in the region in between the hue including the specific region, the upper
Outputs the predetermined matrix coefficient given to the arithmetic term
Force and the matrix given to the above operation terms and the above operation terms
Since the second color data is output by performing the matrix operation including the multiplication of the Rix coefficient, it is possible to independently correct the color of the specific area within the hue without requiring a large capacity memory. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a color conversion device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a configuration of a polynomial calculator in the color conversion device according to the first embodiment.

FIG. 3 is a diagram showing an example of a relationship between the identification code S1 and the hue data having the maximum value β and the minimum value α, 0 in the color conversion device according to the first embodiment.

FIG. 4 is a diagram for explaining the operation of the zero remover of the polynomial calculator in the color conversion device according to the first embodiment.

FIG. 5 is a block diagram showing an example of a configuration of part of a matrix calculator in the color conversion device according to the first embodiment.

FIG. 6 is a diagram schematically showing a relationship between six hues and hue data.

FIG. 7 is a diagram schematically showing a relationship between a multiplication term and a hue in the color conversion device according to the first embodiment.

FIG. 8 is a diagram schematically showing a relationship between a calculation term and a hue based on comparison data in the color conversion device according to the first embodiment.

FIG. 9 is a diagram schematically showing the relationship between the calculation term and the hue based on the comparison data when the calculation coefficient is changed in the calculation coefficient generator 15 of the polynomial calculator in the color conversion apparatus according to the first embodiment. .

FIG. 10 is a diagram showing the relationship of the calculation terms that are effective in relation to each hue and a region between hues in the color conversion device according to the first embodiment.

FIG. 11 is a block diagram showing an example of a configuration of a color conversion device according to a second embodiment of the present invention.

FIG. 12 is a block diagram showing an example of a configuration of a color conversion device according to a third embodiment of the present invention.

FIG. 13 is a diagram showing an example of a configuration of a part of a matrix calculator in the color conversion device according to the third embodiment.

FIG. 14 is a block diagram showing an example of a configuration of a color conversion device according to a fourth embodiment of the present invention.

FIG. 15 is a block diagram showing another example of the configuration of the polynomial calculator in the color conversion device according to the fifth embodiment of the present invention.

FIG. 16 is a diagram schematically showing a relationship between a calculation term and a hue based on comparison data in the color conversion device according to the fifth embodiment.

FIG. 17 is a diagram showing a relationship of effective arithmetic terms involved in each hue and a region between the hues in the color conversion device according to the fifth embodiment.

FIG. 18 is a block diagram showing an example of a configuration of a color conversion device according to a ninth embodiment of the present invention.

FIG. 19 is a block diagram showing an example of the configuration of a polynomial calculator in the color conversion device according to the ninth embodiment.

FIG. 20 is a block diagram showing an example of a configuration of a part of a matrix calculator in a color conversion device according to a ninth embodiment.

FIG. 21 is a diagram schematically showing a relationship between a calculation term and hue based on comparison data in the color conversion device according to the ninth embodiment.

FIG. 22 is a diagram showing a relationship of effective arithmetic terms that are involved in each hue and a region between the hues in the color conversion device according to the ninth embodiment.

FIG. 23 is a block diagram showing an example of a configuration of a color conversion device according to a tenth embodiment of the present invention.

FIG. 24 is a block diagram showing an example of a configuration of a color conversion device according to an eleventh embodiment of the present invention.

FIG. 25 is a diagram showing an example of a configuration of part of a matrix calculator in the color conversion apparatus according to the eleventh embodiment.

FIG. 26 is a block diagram showing an example of a configuration of a color conversion device according to a twelfth embodiment of the present invention.

FIG. 27 is a block diagram showing another example of the configuration of the polynomial calculator in the color conversion device according to the thirteenth embodiment of the present invention.

FIG. 28 is a diagram showing the relationship of the calculation terms that are effective in relation to each hue and the area between the hues in the color conversion device according to the thirteenth embodiment.

FIG. 29 is a block diagram showing an example of a configuration of a conventional color conversion device.

FIG. 30 is a diagram schematically showing a relationship between six hues and hue data in a conventional color conversion device.

FIG. 31 is a diagram schematically showing a relationship between a multiplication term and a hue in a matrix calculator in a conventional color conversion device.

[Explanation of symbols]

1,1b αβ calculator, 2,2b hue data calculator,
3,3b polynomial calculator, 4,4b-4d matrix calculator, 5,5b-5d coefficient generator, 6 combiner, 1
0 complementer, 11 zero remover, 12a, 12b multiplier, 13a, 13b adder, 14a, 14b divider, 15 arithmetic coefficient generator, 16a, 16b arithmetic unit,
17 minimum value selector, 18, 18b minimum value selector, 2
0a to 20f multiplier, 21a to 21e adder, 22
Multiplier, 23 Adder, 30a, 30b Minimum value selector.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Sugiura 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Kazuya Maejima 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. (72) Inventor Takashi Okamoto 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/46-1 / 64 G06T 1/00 510

Claims (10)

(57) [Claims] 1. Color data representing the size of each component of the three primary colors of red, green, blue, or cyan, magenta, and yellow.
In the color conversion device for converting the first color data into the second color data corresponding to the first color data , the achromatic component is removed from the color represented by the first color data.
Colors of red, green, blue, cyan, magenta and yellow
Hue data r, g, b, c, m, y representing the size of the component
And a coefficient generation for outputting a coefficient for designating a specific region between adjacent hues of red, yellow, green, cyan, blue and magenta, which is given for each of the above hue data. Means and a multiplication value obtained by multiplying the hue data by the coefficient, an operation term generating means for generating an operation term which is maximum in the specific area and is effective in the area between the hues including the specific area. If, a matrix coefficient generating means for outputting a predetermined matrix coefficients given to the calculation terms, the matrix given to the upper Symbol calculation terms and the arithmetic term
A color conversion device, comprising: a matrix calculation means for outputting the second color data by performing a matrix calculation including multiplication with a coefficient . 2. The first color data is each component of red, green and blue.
Color data Ri indicating the size, Gi, consists Bi, hue data calculation means, upper Symbol color data R i, G i, B
i and the hue data r = R i −α, g = using the minimum value α and the maximum value β of the color data Ri, Gi, Bi
G i −α, b = B i −α, y = β−B i , m = β−G
i, claim 1, characterized in that to calculate the c = β-R i
The color conversion device described in 1. 3. The first color data is cyan, magenta,
Color data Ci, Mi, representing the size of each yellow component,
It consists Yi, the hue data calculating means, upper Symbol color data M i, C i, Y
i , and the hue data r = β−C i , g = using the minimum value α and the maximum value β of the color data Mi, Ci, Yi.
β−M i , b = β−Y i , y = Y i −α, m = M i −
alpha, claim 1, characterized in that to calculate the c = C i -α
The color conversion device described in 1. Wherein the coefficient generating means, red, yellow, green, cyan, blue, coefficient a p 1~a p 6 for designating a particular region in the adjacent hue of magenta, Aq1～a
Outputs q6, operand generation means, the coefficient a p 1 in each of the hue data
~ A p 6, aq1 to aq6 are used to calculate the red value
~ Yellow, Red ~ Magenta, Yellow ~ Green, Green ~ Shea
Effective in the area between the hues of blue, magenta, cyan, and blue.
An arithmetic term hry = min (aq1 × g, ap1 × m),
hrm = min (aq2 × b, ap2 × y), hgy =
min (aq3 × r, ap3 × c), hgc = min
(Aq4 × b, ap4 × y), hbm = min (aq5
Xr, ap5xc), hbc = min (aq6xg, a
p6 × m) of claims 1 to 3, characterized in that generate
The color conversion device (min (a, b) described in any one of
represents the value of the smallest of a and b) . 5. The matrix calculation means is color data representing the size of an achromatic color component of the color represented by the first color data.
Minimum value and outputs a predetermined matrix coefficients given to alpha of matrix operation means, and the minimum value alpha, the minimum value alpha
5. The color conversion device according to claim 1, wherein the second color data is output by performing a matrix operation including a multiplication with a matrix coefficient given to . 6. Color data representing the size of each component of the three primary colors of red, green, blue, or cyan, magenta, and yellow.
In the color conversion method of converting the first color data into the second color data corresponding to the first color data , the achromatic component is removed from the color represented by the first color data.
Colors of red, green, blue, cyan, magenta and yellow
Hue data r, g, b, c, m, y representing the size of the component
Is calculated, and the coefficient for designating a specific area between adjacent hues of red, yellow, green, cyan, blue and magenta given for each of the above hue data is output, and the above coefficient is added to the above hue data. By using the multiplication value obtained by multiplying by , generate an operation term that becomes the maximum in the specific area and generates an effective operation term in the area between the hues including the specific area, and give it to the operation term. Given matrix coefficient
A matrix that is output and given to the above operation terms and the above operation terms
A color conversion method comprising outputting the second color data by performing a matrix operation including multiplication with a coefficient . 7. The first color data is each component of red, green and blue.
Becomes the color data Ri indicating the size, Gi, from Bi, top Symbol color data R i, G i, B i , and the color data R
Each hue data r = R i −α, g = G i −α, b = B i −α, using the minimum value α and the maximum value β of i, Gi, Bi .
The color conversion method according to claim 6 , wherein y = β-B i , m = β-G i , and c = β-R i are calculated. 8. The first color data is magenta, cyan,
Color data Mi, Ci, representing the size of each component of yellow,
Consists Yi, upper Symbol color data M i, C i, Y i , and the color data M
Hue data r = β-C i , g = β-M i , b = β-Y i , using the minimum value α and the maximum value β of i, Ci, Yi ,
The color conversion method according to claim 6 , wherein y = Y i −α, m = M i −α, and c = C i −α are calculated. 9. red, yellow, green, cyan, blue, coefficient a p 1~a p 6 for designating a particular region in the adjacent hue of magenta, outputs Aq1～aq6, hue data the coefficient of each of the a p 1~a p 6, aq1~
Using the multiplication value multiplied by aq6 , red-yellow, red-ma
Zenta, yellow-green, green-cyan, blue-magenta, shi
An arithmetic term hry = mi effective in the area between the hues of Ann and blue
n (aq1 × g, ap1 × m), hrm = min (aq
2 × b, ap2 × y), hgy = min (aq3 × r,
ap3 × c), hgc = min (aq4 × b, ap4 ×
y), hbm = min (aq5 × r, ap5 × c), h
bc = min (aq6 × g, ap6 × m) color conversion method according to any one of claims 6-8 for the characterized by generate (min (a, b) is a, among the b Be the smallest
Represents the value of things) . 10. A outputs the minimum value predetermined matrix coefficients given for the alpha table to color data size of the achromatic component of color represented by the first color data, and the minimum value alpha, any one of claims 6-9, characterized by outputting the second color data by performing a matrix operation involving multiplication of the Mato <br/> Rikusu coefficient given to the minimum value α The color conversion method described in.