JP2001223911A - Color image processing method and color image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color image processor that can obtain a natural image even when a plurality of selection colors close to each other is simultaneously selected. SOLUTION: An adjustment area for color adjustment is set for every selection color so to discriminate whether or not a received pixel is set in the adjustment area for every selection color. A distance from the selection color of the received pixel in a color space is obtained for every selection color and the adjustment quantity of the received pixel is obtained on the basis of the distance from each selection color. Then the color adjustment of the received pixel is processed on the basis of the calculated adjustment quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color adjustment technique for a color image, and more particularly to a method and apparatus for correcting (adjusting) a plurality of adjacent colors.

[0002]

2. Description of the Related Art In general, there are a YUV system represented by a television and an RGB system represented by a personal computer as a method of expressing colors in a color image. In the YUV method, the color of an image is specified by luminance (Y) and color component (UV). On the other hand, in the RGB system, R (red), G
The color is specified by the ratio of each component of (green) and B (blue).

In performing color adjustment (correction) of an image in any of the YUV and RGB color spaces, a representative color (selected color) is designated, and the representative color and its neighboring colors are adjusted. By the way, in recent years, it has been necessary to adjust a plurality of colors in a color image due to advances in image processing technology and demands of consumers.

[0004]

However, conventionally,
When adjusting a plurality of selected colors in a color image, a clear method for processing when the selected colors are close to each other has not been established. For this reason, it has been difficult to obtain a natural image when a plurality of adjacent selected colors are simultaneously adjusted.

When color adjustment of a color image is performed in the RGB color space, one of the colors may be saturated (exceeding the expression limit), and as a result, the ratio of R, G, and B components changes, This may cause color misregistration. On the other hand, Y
Even when performing color adjustment processing of an image in the UV space, the color difference U,
Any of V may be saturated, causing color shift.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and provides a color image processing method and a color image processing apparatus capable of obtaining a natural image even when a plurality of selected colors adjacent to each other are simultaneously adjusted. The purpose is to provide.

[0007]

In order to solve the above-mentioned problems, in a color image processing method according to a first aspect of the present invention, an adjustment area to be adjusted is set for each of a plurality of selected colors, and input pixels are adjusted. Is determined for each of the plurality of selected colors. The distance of the input pixel from the selected color in the color space is determined for each of the plurality of selected colors, and the adjustment amount of the input pixel is determined based on the distance from each selected color. Then, based on the calculated adjustment amount, color adjustment processing of the input pixel is performed.

[0008] A color image processing apparatus according to a second aspect of the present invention comprises: first data holding means (14) for holding, for each of a plurality of selected colors, data designating an adjustment area to be adjusted;
Based on the data supplied from the first data holding means,
Area determination means (24) for determining, for each of the plurality of selected colors, whether or not the input pixel is within the adjustment area; distance data calculating means (26) for calculating data relating to the distance of the input pixel from the plurality of selected colors in the color space Adjustment processing means (28) for performing color adjustment processing of input pixels for each of a plurality of selected colors based on data supplied from the distance data calculation means; and, as a result of determination by the area determination means, Output means for selecting the output of the adjustment processing means if it is within any of the adjustment areas in the selected color, and selecting and outputting the data of the input pixel as it is if not included in any of the areas (3
0, 32).

In the present invention as described above, when a plurality of colors (selected colors) existing in a color image are simultaneously corrected, natural color adjustment can be performed even when these selected colors are close to each other. This has the effect.

In the present invention as described above, more preferably, when the adjustment value is added to each color component, the saturation state of each component is detected, and the addition process is adjusted based on the detection result. This makes it possible to prevent color shift due to saturation of any color component.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. In the embodiment described below, a method and an apparatus for correcting a plurality of selected colors close to each other in an RGB digital image will be described as an example. In the description and drawings, "P"
And “C” indicate a vector value in the RGB color space.

First, the basic principle of the present invention will be described with reference to FIG. FIG. 1 is a diagram for explaining the concept of a color adjustment region determination method for a color image according to an embodiment of the present invention, and shows an RGB color space. In FIG. 1, (1) shows the relationship between two selected colors a and b that are close to each other, and (2) shows the relationship between the three selected colors a and b.
(3) shows the relationship between four or more adjacent selected colors a, b, c, and d.

In the present embodiment, as shown in FIG. 1B, color correction is performed based on three selected colors. As shown in (3), when four or more selected colors are close to each other, it can be regarded as the same as increasing the correction area of one color.
In order to simplify the operation relating to the color correction as much as possible, the following embodiment will be described based on the case where three colors are close to each other.

FIG. 2 shows a color image according to an embodiment of the present invention.
1 shows a configuration of a processing device. Color image processing apparatus shown in FIG.
Is the input pixel data P_inOutput (vector value)
An image input device 12, a memory 14 for specifying a correction area,
Color data C of color specification (selection color) ₁, C₂, C₃(vector
), And a representative color designating memory 16 for storing the representative colors.
For specifying the correction amount that holds the positive amount ΔC (ΔR, ΔG, ΔB)
And a memory 18. Correction area designation memory 14
Is the RGB space between each selected color and the input pixel (correction target color)
Of the distance at (L₁, L₂, L₃) (1)
/ L₁, 1 / L ₂, 1 / L₃) Hold. Maximum distance
Value (L₁, L₂, L₃) Is the boundary of the correction area for each selected color
Is shown.

The color image processing apparatus according to this embodiment is
A color correction area determination circuit 24 for determining a color correction area;
Coefficient for color correction (Δr₁, Δr₂, Δr₃)
The coefficient determination circuit 26 and an input pixel (P_in)
Correction operation circuit 28 for performing processing, selector 30,
And an output device 32. Color correction coefficient (Δ
r ₁, Δr₂, Δr₃) Takes a value of 0 to 1.

The output terminals of the image input device 12 are a selector 30, a color correction area determination circuit 24, and a color correction arithmetic circuit 28.
Are respectively connected to the input terminals. Then, RGB data _{P in} of the input pixel from the image input device 12, a selector 30, a color correction region determining circuit 24 and the color correction operation circuit 28
Supplied to The output terminal of the correction area designating memory 14 is connected to another input terminal of the color correction area determination circuit 24, and the RGB of the selected color and the input pixel (correction target color).
The reciprocal of the maximum value of the distance in space (1 / L ₁ , 1 /
L ₂ , 1 / L ₃ ).

The output terminal of the representative color designation memory 16 is connected to another input terminal of the color correction area determination circuit 24, and the color data C ₁ , C ₂ , C ₃ of each selected color is determined by the color correction area determination. A circuit 24 is provided. The output terminal of the correction amount specifying memory 18 is connected to the input terminal of the color correction operation circuit 28 so that the correction amounts ΔC (vector values) of the three selected colors are supplied to the color correction operation circuit 28. I have.

An output terminal of the color correction area determination circuit 24 is connected to an input terminal of a color correction operation circuit 28 via a coefficient determination circuit 26. The output terminal of the color correction area determination circuit 24 is further connected to the input terminal (control terminal) of the selector 30. The color correction area determination circuit 24 includes a selector 30
, A control signal indicating whether or not the input pixel is within the correction area is supplied. Distance coefficient determination circuit 26, the input pixel _{P in} each selected color and _{(C 1, C 2, C} 3) ( scalar quantity)
Are supplied to the correction operation circuit 28 as color correction coefficients (Δr ₁ , Δr ₂ , Δr ₃ ).

The output terminal of the correction operation circuit 28 is connected to a selector
30 are connected to one input terminal. Correction calculation circuit
28 is a memory 18 for specifying the amount of correction and a coefficient determination circuit 26
ΔC (ΔR, ΔG, ΔB), Δr₁, Δr₂, Δr₃  Based on the input pixel P_inCorrection value (addition value)
｛1− (Δr₁+ Δr₂+ Δr₃+1) / 4｝ × ΔC is calculated.

The correction calculation circuit 28 further calculates the corrected pixel value P of the input pixel P _in according to the calculation shown in the following equation.
_out is calculated. P _out = P _in + ｛1- (Δr ₁ + Δr ₂ + Δr ₃ +
1) / 4｝ × ΔC

The selector 30 includes a color correction area determination circuit 26
The color data P _in supplied from the image input device 12 and the corrected color data P _out = P _in + ｛1- (Δr ₁ + Δr ₂ + Δr ₃₎ supplied from the correction operation circuit 28 based on the control signal from +
1) One of / 4｝ × ΔC is supplied to the image output device 32 as P _out . That is, when the input pixel P _in any of the selected color correction region, select the data after correction supplied from the correction calculation circuit 28, the correction region of any selected color input pixel P _in the if even deviates selects input data P _in supplied from the image input device 12.

FIG. 3 shows a logical configuration of the color correction area determination circuit 24 and the coefficient determination circuit 26. Fig. 4 (1) shows the areas of three selected colors (I, II, III, IV, V, VI, VII).
Are shown separately. FIG. 4B shows how to attach a flag for each selected color. Input pixel data _{P in} the three subtracters 4
0, 42, and 44. Subtractors 40, 42, 44
, The center point data of the three selected colors is input. Then, the subtraction processing by the subtracter 40, 42, 44, obtains a distance between the input pixel data _{P in} the three selected color _{(Δr 1, Δr 2, Δr} 3). Output terminals of the subtracters 40, 42, and 44 are connected to an absolute value generation circuit 40.
a, 42a, and 44a, respectively.
The output terminals of the absolute value generation circuits 40a, 42a, 44a are:
Each of the multipliers 46a, 48a, 50a is connected to one input terminal. The other input terminals of the multipliers 46a, 48a, and 50a have three selected color correction area range data 1
/ L ₁ , 1 / L ₂ , 1 / L ₃ are supplied. The output terminals of the multipliers 46a, 48a, 50a are connected to three flag setting units 46, 48, 50, respectively. "1" is supplied to the other input terminals of the flag setting units 46, 48 and 50, respectively.

As shown in FIG. 4, when the distance between the input pixel and the selected color is within the corresponding correction area range, a flag 1 is added. When the flag 1 is added to the input pixel data, the distance coefficient (Δr) is output as it is. On the other hand, if the distance between the input pixel and the selected color is outside the corresponding correction area range, a flag 0 is added. When the flag 0 is added to the input pixel data, “1” is output as the distance coefficient (Δr).

FIG. 5 (1) is schematically a when located all the correction areas of the input pixel _{P in} the three selected color, distance to each selected color ([Delta] r _1, [Delta] r _2, [Delta] r ₃₎ Shown in
FIG. 5B shows the configuration of the color correction operation circuit 28. The color correction operation circuit 28 includes adders 52 and 60, a 2-bit shifter 54, a subtractor 56, and a multiplier 58.

The input terminal of the adder 52 has up to each selected color.
Distance coefficient (Δr₁, Δr₂, Δr ₃) Is the coefficient setting circuit
26, and these are added. Adder 52
Output terminal is a 2-bit shifter via an incrementer
-54 input terminal. One of the subtractors 56
Is connected to the output terminal of the 2-bit shifter 54.
Then, “1” is input to the other input terminal. Multiplication
The output terminal of the subtractor 56 is connected to one input terminal of the
Connected, and the other input terminal has the common
A positive amount ΔC is input. To one input terminal of the adder 60
Is connected to the output terminal of the multiplier 58 and the other input terminal
Has input pixel data P_inIs entered.

With the configuration of the color correction arithmetic circuit 28 as described above, the corrected color data P _out = P _in + ｛1- (Δr ₁ + Δr ₂ + Δr ₃ +
1) Calculate / 4｝ × ΔC.

Next, the arithmetic processing P _out = P _in + ｛1- (Δr ₁ + Δr ₂ + Δr ₃ +) finally performed by the color correction arithmetic circuit 28
1) A method of deriving / 4｝ × ΔC will be described. When there is one selected color to be corrected, the corrected output data P _out can be obtained by the following equation (1). P _out = P _in + (1−Δr) × ΔC (1) where P _in is the input pixel value (vector), P _out is the output pixel value (vector), and Δr is the selected color in the RGB color space. , And ΔC are correction amounts (vectors) for the selected color.

The calculation in the case where the three selected colors are close to each other is performed by linearly adding the above equation (1) and expanding the equation as shown in the following equation (2). Pout = Pin + (1-Δr1) × ΔC1 + (1-Δr2) × ΔC2 + (1-Δr3) × ΔC3 (2) where the distance of the input pixel from the first selected color in the color space Is Δr1, the adjustment amount in the first selected color is ΔC1, the distance of the input pixel from the second selection color in the color space is Δr2, and the adjustment amount in the second selection color is ΔC2. The distance of the input pixel from the third selected color in the color space is Δr3, and the adjustment amount in the third selected color is ΔC3.

Further, various approximate expressions are used to simplify the hardware configuration. In the above equation (2), since the three selected colors are close to each other, the correction amounts ΔC1, ΔC2,
It is considered that ΔC3 is also substantially equal. Therefore, the following equation (3) is obtained by modifying equation (2). Pout = Pin + {1- (Δr1 + Δr2 + Δr3) / 3} × (ΔC1 + ΔC2 + ΔC3) (3)

In equation (3), to avoid multiplication by 1/3, equation (3) is virtually expanded to equation (4) for four colors. Pout = Pin + {1- (Δr1 + Δr2 + Δr3 + Δr4) / 4} × (ΔC1 + ΔC2 + ΔC3 + ΔC4) (4)

As described above, since it is not necessary to consider proximity processing for four or more colors, in equation (4), Δr4 = 1, ΔC4 = δ = (ΔC1 + ΔC2 + ΔC
The following equation (5) is obtained as 3) / 3. Pout = Pin + {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × (ΔC1 + ΔC2 + ΔC3 + δ) (5)

Further, in equation (5), ΔC = ΔC1 +
Assuming that ΔC2 + ΔC3 + δ, the parameters set in the hardware device are only three components of ΔC (ΔR, ΔG, ΔB), and finally the following equation (6) can be used. Pout = Pin + {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × ΔC (6) The apparatus shown in FIG. 2 employs a configuration based on the above equation (6).

Next, the overall operation of the apparatus of FIG. 2 will be described with reference to the flowchart of FIG. In the color correction area determination circuit 24, selected color (representative color) data C1, C2, and C3 supplied from the representative color designation memory 16; and pixel data P _in (R,
G, B); correction target area data (1 / L ₁ , 1 / L ₂ , 1 / L ₃ ) supplied from the correction area specifying memory 14
Based on this, the area determination processing is performed. That is, whether the input pixel P _in is in any of the selected color correction region.

The result of the determination, if the input pixel P _in is out of correction area of all selected colors, by the function of the selector 30, input data P _{in (R,} G, B) as it is an image output device 32. On the other hand, the result of the determination, if the input pixel P _in is in at least one selected color correction region, performs correction processing. That is, in the color correction arithmetic circuit 28, the correction amount data ΔC supplied from the correction amount designating memory 18 and the distance coefficient data (Δr ₁ , Δr ₂ , Δr ₃ ) supplied from the coefficient determination circuit 26.
Based on the above, the corrected pixel data P ′ (R ′, G ′, B ′) is calculated by the calculation of the above-described equation (6). And
By controlling the selector 30, the corrected data is supplied to the image output device 32.

In the correction operation circuit 28, it is preferable to add a saturation processing function in addition to the above functions. That is, a process for preventing any color from being saturated at the stage of RGB color correction is performed. First, FIGS. 7 and 8
The first method of the saturation processing will be described with reference to FIG. In the following description, the color correction component is represented by ΔP (= ΔR, ΔR
G, ΔB). Also, ΔP = {1- (Δ
r1 + Δr2 + Δr3 + 1) / 4} × ΔC

In the first method, first, the color correction components ΔP (= ΔR, ΔG, ΔB) are equally divided into n (n> 1),
The value ΔP / n (= ΔR / n, ΔG / n, ΔB / n) is added to each color. If any of the colors is saturated at this stage, the value obtained by stopping the addition is output to the image output device 32 as an output P _out . When none of the colors is saturated, the value ΔP / n (= ΔR / n, ΔG /
n, ΔB / n) are added to each color. Such an operation is repeated at most n times, and when any color is saturated, the addition is stopped and the obtained value is used as a P _out signal (R _out , G _out) .
_out , B _out ) to the image output device 32.

In the cases shown in FIGS. 7 and 8, n = 4. In this case, since the red (R) is saturated in the third addition, P is added without performing the fourth addition.
Let _in + 3ΔP / 4 be the output signal P _out .

The detection of the saturated state can be realized by a so-called overflow detection. That is, when performing the addition of 8 bits + 8 bits, “0” is added to the highest order in both the addition number and the augend, and the operation is performed with 9 bits. When the result of the addition exceeds the 8-bit range, "1" is entered at the ninth bit. Therefore, by detecting the ninth bit for R, G, and B, it can be determined whether the color is saturated.

The division of the color correction component ΔP is not limited to four, but by dividing it into four, the hardware configuration can be simplified (the number of operations can be reduced).

Next, a second method of the saturation processing in the correction operation circuit 28 will be described. In the second method, first, ΔP / 2 ¹ (= ΔR / 2 ¹ , ΔG / 2 ¹ , Δ
B / 2 ¹ ) is added to each color. If any color is saturated at this stage, the value ΔP / 2 ² (= ΔR / 2 ² ,
ΔG / 2 ² , ΔB / 2 ² ) are subtracted from each color. Finally, P + ΔP / 2 ² (= R + ΔR /
^{2 2, G + ΔG / 2} 2, B + ΔB / 2 2 the output signal P
Output to the image output device 32 (display device) as _out (R _out , G _out , B _out ).

On the other hand, the value ΔP / 2 ¹ (= ΔR / 2 ¹ , ΔG
/ 2 ¹ , ΔB / 2 ¹ ) is added to each color, and if none of the colors is saturated, the value ΔP / 2 ² (= Δ
R / 2 ² , ΔG / 2 ² , ΔB / 2 ² ) are added to each color, and the addition process ends. That is, P + 3ΔP / 2
² (= R + 3ΔR / 2 ² , G + 3ΔG / 2 ² , B + 3Δ
B / 2 ² is output to the output signal P _out (R _out , G _out , B
_out ) to the image output device 32.

In the embodiment shown in FIGS. 9 and 10, "2" is adopted as the number of divisions n in the second method. FIG. 11 shows the concept of the saturation processing shown in FIGS. 9 and 10. Here, “n” indicates the number of times (the number of stages) of performing the addition.

Also in the second method, the detection of the saturated state can be realized by the overflow detection described above.
According to the second method, since the saturation processing can be performed by two-stage addition (subtraction) processing, the hardware configuration can be further simplified as compared with the first method.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, but can be modified within the scope of the technical idea described in the claims. is there.

[0045]

As described above, according to the present invention,
When simultaneously correcting a plurality of colors (selected colors) existing in a color image, there is an effect that natural color adjustment can be performed even when these selected colors are close to each other.

When performing color correction of input pixels, RG
By detecting the saturation state of each value B and adding a correction value according to the state, it is possible to prevent the occurrence of a color shift due to saturation during color adjustment.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a basic idea of the present invention, and shows an RGB color space.

FIG. 2 is a block diagram illustrating a configuration of a color image adjustment device according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a configuration of a main part of the embodiment, and corresponds to a color correction area determination circuit and a coefficient determination circuit in the device illustrated in FIG. 2;

FIG. 4 is an explanatory diagram for explaining an operation of the configuration shown in FIG. 3;

FIG. 5 is an explanatory diagram showing a configuration of a main part of the embodiment, and corresponds to a color correction operation circuit in the device shown in FIG. 2;

FIG. 6 is a flowchart showing the operation of the embodiment shown in FIG. 2;

FIG. 7 is a flowchart illustrating a first method in a color adjustment saturation process applied to the embodiment;

FIG. 8 is an explanatory diagram schematically showing the operation shown in FIG. 7;

FIG. 9 is a flowchart illustrating a second method in a color adjustment saturation process.

FIG. 10 is an explanatory diagram schematically showing the operation shown in FIG. 9;

FIG. 11 is an explanatory diagram showing the concept of the saturation processing shown in FIGS. 9 and 10;

[Explanation of symbols]

 REFERENCE SIGNS LIST 12 Image input device 14 Correction area specifying memory 16 Representative color specifying memory 18 Correction amount specifying memory 20 Relative luminance calculation circuit 24 Color correction area determination circuit 26 Coefficient determination circuit 28 Color correction calculation circuit

Continued on the front page F-term (reference) PQ20 5C079 HB01 LA06 LB01 MA11 NA03

Claims (16)

[Claims] 1. A color image processing method for adjusting a plurality of selected colors in a color image, comprising: setting an adjustment area to be adjusted for each of the plurality of selected colors; and determining whether the input pixel is within the adjustment area. Determining for each of the plurality of selected colors; determining the distance of the input pixel from the selected color in the color space for each of the plurality of selected colors; and based on the distance from each of the selected colors. A color image processing method comprising: a step of calculating an adjustment amount of the input pixel; and a step of performing a color adjustment process of the input pixel based on the adjustment amount. 2. The color image processing method according to claim 1, wherein the plurality of selected colors are three colors close to each other. 3. The method according to claim 1, wherein the color data of the input pixel is Pin, the distance of the input pixel from the first selected color in the color space is Δr1, and the adjustment amount of the first selected color is ΔC1. The distance from the second selected color in the color space of Δr2, the adjustment amount in the second selected color as ΔC2, the distance of the input pixel from the third selected color in the color space as Δr3, When the adjustment amount for the selected color No. 3 is ΔC3, the color data Po after the color adjustment
3. The color image processing method according to claim 2, wherein ut is calculated according to the following equation. Pout = Pin + (1-Δr1) × ΔC1 + (1-Δr2) × ΔC2 + (1-
Δr3) × ΔC3 4. The color image according to claim 3, wherein δ = 1/3 (ΔC1 + ΔC2 + ΔC3), and the color data Pout is calculated by transforming the above expression into the following expression. Processing method. Pout = Pin + {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × (ΔC1 + ΔC2 +
ΔC3 + δ) 5. The color adjustment processing includes: adding the adjustment amount to a color component of the input pixel; detecting a saturation state of the input pixel; and adjusting the addition processing based on the detection result. 5. The color image processing method according to claim 1, wherein the color image processing method comprises: 6. The method according to claim 1, wherein in the step of adding the adjustment amount to the color component of the input pixel, the adjustment amount is divided, and the divided adjustment amount is added stepwise to the color component of the input pixel. A color image processing method according to claim 5. 7. When ΔP = {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × ΔC, the adjustment amount ΔP is divided into ΔP / n by n equal parts (n>
1) The method according to claim 6, wherein ΔP / n is added to the input pixel until one of the color components of the input pixel is saturated. 8. The color adjustment amount (ΔC1 + ΔC2 + ΔC3 + δ) = ΔC
, The color component of the input pixel is first Δ
Plus P / ^{2 1,} by the addition of the [Delta] P / ^{2 1,} when any of the color components is saturated, subtracts the [Delta] P / ^{2 2} from each color component, by the addition of the [Delta] P / ^{2 1,} If none of the color components is saturated, ΔP / 2 is further applied to each color component.
7. The color image processing method according to claim 6, further comprising a process of adding ² . 9. A color image processing apparatus for adjusting a plurality of selected colors in a color image, a first data holding means for holding data specifying an adjustment area to be adjusted for each of the plurality of selected colors; The first
Area determination means for determining, for each of the plurality of selected colors, whether or not the input pixel is within the adjustment area, based on data supplied from the data holding means; and the plurality of selected colors of the input pixel in a color space. Distance data calculation means for calculating data relating to the distance from the camera; based on data supplied from the distance data calculation means, for each of the plurality of selected colors,
Adjustment processing means for performing color adjustment processing of the input pixel; and, as a result of the determination by the area determination means, when the input pixel is within any one of the adjustment areas in the plurality of selected colors, the adjustment processing means An output unit for selecting an output and selecting and outputting data of the input pixel as it is when the data is not included in any of the areas. 10. The method according to claim 1, wherein the plurality of selected colors are three colors which are close to each other.
The color image processing apparatus according to claim 9, wherein the color image processing apparatus uses a color. 11. The adjustment processing means, wherein the color data of the input pixel is Pin, the distance of the input pixel from the first selected color in the color space is Δr1, and the adjustment amount of the first selected color is ΔC1, the distance of the input pixel from the second selected color in the color space is Δr2, the adjustment amount in the second selected color is ΔC2, the distance of the input pixel from the third selected color in the color space. To Δr3
11. The color image processing apparatus according to claim 10, wherein the color data after color adjustment Pout is calculated according to the following equation, when the adjustment amount of the third selected color is set to ΔC3. Pout = Pin + (1-Δr1) × ΔC1 + (1-Δr2) × ΔC2 + (1-
Δr3) × ΔC3 12. In the adjustment processing means, δ = 1/3 (Δ
The color image processing apparatus according to claim 11, wherein the color data Pout is calculated by changing the above equation to the following equation (C1 + ΔC2 + ΔC3). Pout = Pin + {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × (ΔC1 + ΔC2 +
ΔC3 + δ) 13. The color adjustment processing in the adjustment processing means includes adding the adjustment amount to a color component of the input pixel, detecting a saturation state of the input pixel, and performing an addition process based on the detection result. 13. The color image processing apparatus according to claim 9, wherein the adjustment is performed. 14. When the adjustment amount is added to the color component of the input pixel by the adjustment processing means, the adjustment amount is divided and the divided adjustment amount is added to the color component of the input pixel in a stepwise manner. 14. The color image processing apparatus according to claim 13, wherein: 15. ΔP = {1- (Δr1 + Δr2 + Δr3 + 1) / 4} × ΔC
, The adjustment amount ΔP is divided into ΔP / n by n equal parts (n>
1) The color image processing apparatus according to claim 14, wherein ΔP / n is added to the input pixel until one of the color components of the input pixel is saturated. 16. The color adjustment amount in the adjustment processing means.
When (ΔC1 + ΔC2 + ΔC3 + δ) = ΔC, first, ΔP / 2 ¹ is added to the color component of the input pixel, and any of the color components is added by the addition of ΔP / 2 ¹ . Is saturated, ΔP / 2 ² is subtracted from each color component. If none of the colors of the color components is saturated by the addition of ΔP / 2 ¹ , ΔP / 2 is further added to each color component.
15. The color image processing apparatus according to claim 14, further comprising a process of adding ² .