JP2003163814A - Color adjustment device - Google Patents

Abstract

[Problem] To provide a color adjustment device capable of performing color determination and color adjustment in HSV without performing color space conversion processing on color signals represented in RGB. Comparing means (large / small comparator 1) for outputting a maximum value, a median value, and a minimum value based on an input RGB signal, and a hue for determining a hue of input data and outputting an identification code Determination means (hue determination device 2), adjustment value calculation means (adjustment value calculator 3) for outputting the hue adjustment value, saturation adjustment value, and brightness adjustment value set for each hue, and the brightness of the input data Brightness adjustment means for adjusting the color (lightness adjuster 5), saturation adjustment means for adjusting the saturation of the input data (saturation adjuster 4), and hue adjustment for adjusting the hue of the input data Means (hue adjuster 6) and selection means (RGB selector 7) for returning the αβγ signal back to the original RGB signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color adjusting device for performing color adjustment on a color image.

[0002]

2. Description of the Related Art In a display device such as a monitor, when an input color signal is displayed, color adjustment processing is performed in order to output an image having desired color reproducibility in accordance with usage conditions. In this color adjustment process, using hue, saturation, and lightness (HSV) has the advantage of being easier to understand as human senses and easier to adjust than using red, green, and blue (RGB signals). is there.

Conventionally, when performing color adjustment by HSV, color space conversion from an input color space (RGB) to HSV is performed, color adjustment is performed by increasing or decreasing the value of HSV, and then the original color space is adjusted. A method of returning to the color space (RGB) is common. However, the color space conversion to HSV cannot be performed by a general matrix operation,
There is a problem that the processing procedure and time required for conversion become very large. Various techniques have been proposed as means for avoiding this.

For example, Japanese Unexamined Patent Publication No. 8-204976
The disclosed color image processing device is a device such as CMYK.
Vice dependent color is L^*a^*b^*Device-independent colors such as
It is related to color matching when doing
LUT by separating each color of black, magenta, and yellow from black
By performing color conversion using
Achieving a reduction in memory. That is, as shown in FIG.
3D LUT color converters 51-53
Color signal L based on only CMY of the CMYK signals ₂ ^*, A
₂ ^*, B₂ ^*To generate. This color signal L₂ ^*, A₂ ^*, B₂ ^*L
^*a^*b^*The position in space is the output color that should actually be generated.
Signal L₁ ^*, A₁ ^*, B₁ ^*There is a deviation from.

The one-dimensional LUT 54 generates a lightness signal L ₃ ^* based on the K color component of the input color signal. This brightness signal L
_{The 3} ^* corresponds to the deviation described above. The color signal synthesizing means 55 uses the color signals L ₂ ^* , a ₂ ^* , b ₂ ^* and the lightness signal L ₃ ^*.
The final output color signals L ₁ ^* , a ₁ ^* , b ₁ ^* are generated based on

The device for determining the path of the interpolator input data disclosed in Japanese Patent Laid-Open No. 10-117291 relates to speeding up of color space conversion processing and simplification of hardware, and is optimal. By performing the interpolation process, simplification of the color conversion using the LUT is realized. That is, as shown in FIG. 15, when converting an input color space such as RGB to an output color space such as CMYK, a 2's complement process is selected by the low order bits of the input color data divided into high order bits and low order bits. And then using the result of the interpolating means, the path of the input data of the interpolating circuit is determined to the correct calculation block in the interpolating circuit.

A color conversion table creating apparatus and a creating method disclosed in Japanese Patent Laid-Open No. 2000-253270,
In order to efficiently create a color conversion table for converting a color value of a device-dependent color space into a color value of a device-independent color space, a recording medium recording a color conversion table creation program and a color conversion device. The present invention realizes the object of the invention by comparing a color patch of a color target to be referenced with a color patch obtained by color-converting an input image by an LUT and correcting the LUT value from the color difference. . That is, in FIG.
As shown in (a) and (b), an initial value LUT having color values corresponding to the color conversion grid points is prepared, and the color patch side color values L ^* a ^* b ^* (β) are output from the input device. Initial L
Color patch output value L ^* a ^* b color-converted by UT
^* (Α) is compared to obtain the color difference for each color patch number i, and the color value of the initial LUT is corrected using this color difference.

At this time, the distance d between the color patch and the grid point
Accordingly, the closer the grid point is to a certain color patch, the larger the influence due to the color difference in the color patch is, and the weighting is performed. Also, the color value of the initial LUT is corrected only for grid points (neighboring grid points) within a predetermined distance (correction distance D) from a certain color patch. This series of correction processing,
The LUT is corrected again while the correction distance D is narrowed.

The color conversion device and color conversion method disclosed in Japanese Patent Laid-Open No. 2000-287074 are open to flexible color conversion methods that do not require a large-capacity memory, and use matrix operations. The object of the invention is realized by independently correcting the six hues and the inter-hue area.

That is, as shown in FIG. 17, means (αβ calculator 61) for calculating the minimum value α and the maximum value β of the input data R, G, B and the input data R, G, B,
Means for calculating the hue data using the minimum value α and the maximum value β (hue data calculator 62), and means for generating the first comparison data between the hue data using the hue data, Means for generating second comparison data between the hue data using the first comparison data, means for performing an operation between the hue data (polynomial calculator 63), and generating predetermined matrix coefficients Means (coefficient generator 65) for performing a predetermined matrix operation using the first and second comparison data, the output from the polynomial operator 63, the hue data r, g, b, and the matrix coefficient,
A means for outputting the data after the calculation (matrix calculator 64), and a means for adding the minimum value α to the output data and synthesizing and outputting the color-converted data (synthesizer 66) Is equipped with.

In the technique disclosed in Japanese Unexamined Patent Publication No. 8-204976 mentioned above, the required storage capacity is reduced by separating the LUT used for color conversion by color components, and Japanese Unexamined Patent Publication No. 10-117291. In the technique disclosed in the publication, the calculation block path of the interpolation circuit is determined to simplify the interpolation calculation, that is, the LUT. Further, in the technique disclosed in Japanese Patent Laid-Open No. 2000-253270, the LUT is corrected by the color patch comparison calculation to realize the optimum color conversion. The common point of these techniques is to use an LUT at the time of color conversion, but even if the storage capacity of the LUT is reduced by optimization, there is a limit to the reduction amount.

Further, in the technique disclosed in Japanese Unexamined Patent Publication No. 2000-287074, color conversion is performed by matrix calculation, and since a LUT is not used, a large capacity memory is unnecessary. However, in the matrix calculation formula, the matrix coefficient Fij is i = 1 to 3, j = 1 to
Since it is 5, the calculation becomes relatively large, and the circuit scale becomes large when implemented as hardware.

[0013]

As described above, in the conventional technique, the LUT (look-up table) is used in the color conversion by the color conversion table for adjusting the color of the RGB signal by HSV. However, there is a problem that a large-capacity memory is required, it is difficult to simplify the apparatus, and it is not possible to flexibly cope with changes in usage conditions.

Further, in the color adjustment by separating the hue component,
Color adjustment in the HSV3 attribute is not considered. For this reason, it is difficult to perform a process in which only the hue is adjusted without changing the saturation and the brightness, and there is a problem that the clear color adjustment of the saturation and the brightness cannot be performed.

The present invention has been made to solve the above-mentioned problems, and color determination and color adjustment by HSV are performed on a color signal represented by RGB without performing color space conversion processing. It is an object of the present invention to provide a color adjusting device capable of performing.

[0016]

A color adjusting apparatus according to the present invention calculates and outputs a maximum value α, a median value β, and a minimum value γ, which are magnitude relationships, based on RGB signals which are input data. Means for comparing with the input data R
The GB signal and the maximum value α output from the comparison means,
It is set for each hue by using the median value β and the minimum value γ, the hue determining means for determining the hue of the input data and outputting the identification code, and the identification code output from the hue determining means. Hue adjustment value Ah, saturation adjustment value As,
And an adjustment value calculating means for outputting the brightness adjustment value Av, and a brightness for adjusting the brightness of the input data using the maximum value α, the median value β, the minimum value γ, and the brightness adjustment value Av. Adjusting means, a saturation adjusting means for adjusting the saturation of the input data using the maximum value α, the median value β, the minimum value γ, and the saturation adjusting value As; and the maximum value α, Hue adjusting means for adjusting the hue of the input data using the median value β, the minimum value γ, and the hue adjustment value Ah, and the maximum value α, the median value β, the minimum value γ, and the It is characterized in that it is provided with a selecting means for returning the αβγ signal to the original RGB signal by using the identification code.

Further, in the color adjusting device, the hue determining means has a correspondence relationship between the RGB signal which is the input data and the maximum value α, the median value β and the minimum value γ output from the comparing means. And the relative value relationship of the median β, the maximum α, and the minimum γ, the hue of the input data is determined, and the adjustment value calculation means is the hue determined by the determination means. The hue adjustment value Ah and the saturation adjustment value As set for each hue based on
And the brightness adjustment value Av is output.

Further, in the color adjusting device, the brightness adjusting means is configured to set the maximum value α and the median value based on the maximum value α, the median value β, the minimum value γ, and the brightness adjustment value Av. β, while maintaining the ratio of the maximum value α and the minimum value γ constant, adjust the maximum value α, the median value β, and the minimum value γ according to the brightness adjustment value Av, and The configuration includes a lightness clip processing unit for adjusting the maximum value α, the median value β, and the minimum value γ so as not to overflow or underflow.

In the color adjusting device, the lightness clip processing means may cause the lightness adjusting means to perform the maximum operation based on the maximum value α, the median value β, the minimum value γ, and the lightness adjustment value Av. It is configured to include a clipping unit for detecting the case where the value α, the median value β, and the minimum value γ are overflow or underflow, and clipping the brightness adjustment value Av in advance.

Further, in the color adjusting apparatus, the saturation adjusting means changes the maximum value α based on the maximum value α, the median value β, the minimum value γ, and the saturation adjustment value As. Without maintaining the ratio of the difference data between the maximum value α and the median value β and the difference data between the median value β and the minimum value γ, the median value β is adjusted according to the saturation adjustment value As. And a saturation clip processing means for adjusting the minimum value γ and adjusting the adjustment so that the median value β and the minimum value γ are not larger than the maximum value α or underflow.

Further, in the color adjusting device, the saturation clipping processing means, based on the maximum value α, the median value β, the minimum value γ, and the saturation adjustment value As, the saturation adjustment means. The median value β and the minimum value γ
Is larger than the maximum value α or underflow is detected, and the saturation adjustment value As is clipped in advance.

Further, in the color adjusting device, the hue adjusting means is configured to set the maximum value α and the minimum value based on the maximum value α, the median value β, the minimum value γ, and the hue adjustment value Ah. A hue for adjusting the median value β according to the hue adjustment value Ah without changing γ and adjusting the median value β so as not to be larger than the maximum value α or smaller than the minimum value γ. The clip processing means is included.

In the color adjusting device, the hue clip processing means determines, based on the maximum value α, the median value β and the minimum value γ, that the median value β is larger than the maximum value α. The median value β is clipped to the maximum value α, the difference between the median value β and the maximum value α is subtracted from the maximum value α, and when the median value β is smaller than the minimum value γ, the median value β To the minimum value γ,
The difference between the minimum value γ and the median value β is added to the minimum value γ.

[0024]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of a color adjusting apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a color adjusting apparatus according to an embodiment of the present invention. A color adjusting apparatus according to an embodiment of the present invention is shown in FIG.
As shown in, the maximum value α of the input data Ri, Gi, Bi
i, the median value βi, and the minimum value γi are calculated and output, and the magnitude comparator 1 for generating and outputting the identification code S1 for identifying the corresponding relationship, and S1 and αi, βi,
A hue determiner 2 for performing a hue determination of input data based on γi and outputting a hue code S2 for identifying the determined hue.
And the adjustment values As and A set for each hue based on S2.
adjustment value calculator 3 for outputting v, Ah, and αi, β
i, γi are adjusted according to As, and α1, β1, γ after adjustment
Saturation adjuster 4 for outputting 1, and α1, β1, γ1
And a lightness adjuster 5 for adjusting α according to Av to output adjusted α2, β2, γ2, and a hue adjuster for adjusting α2, β2, γ2 according to Ah and outputting adjusted α3, β3, γ3. 6 and an RGB selector 7 for distributing α3, β3, γ3 into the original RGB signals according to S2 and outputting Ro, Go, Bo.

In this color adjusting apparatus, the input color data Ri, Gi, Bi is sent to the magnitude comparator 1, and the magnitude comparator 1 outputs the maximum value αi, based on the input color data Ri, Gi, Bi. The median value βi and the minimum value γi are calculated and output, and the identification code S1 for specifying the maximum value data, the median value data, and the minimum value data of Ri, Gi, and Bi is generated. And output.

FIG. 2 shows the identification code S1 and Ri, Gi, B.
It is explanatory drawing which shows the relationship of i, (alpha) i, (beta) i, (gamma) i. It should be noted that the value of the identification code S1 in the drawing is one example, and may be another value. The hue determiner 2 uses αi, β
i, γi are input, and the difference data ψ = αi− between αi and βi
Difference data ω = βi−γi of βi, βi and γi is calculated, and the magnitude comparison of ψ and ω is performed. Based on this result and the identification code S1, the hue to which the input data belongs is determined, and the hue code S2 is generated.

FIG. 3 is a schematic diagram showing the hue determination by the hue determiner 2, and FIG. 4 is the hue code S2 and the determined hues S and S.
It is explanatory drawing which shows the relationship of 1 and (psi)-(omega). For example, if the input data is Ri = 200, Gi = 80, and Bi = 160, αi is determined to be Ri, so the hue is between magenta and yellow, and βi is Bi, so magenta to red. It is narrowed down. Finally, ψ = 40, ω
= 80, the hue of the input data is finally identified as magenta, and the hue code S2 = 10 is output. It should be noted that the value of the hue code S2 in the figure shows an example thereof, and may be another value.

The adjustment value calculator 3 receives S2 and inputs the hue adjustment value Ah and the saturation adjustment value A set to the determined hue.
s and the brightness adjustment value Av are output. By setting different adjustment values for each hue, color adjustment can be performed independently for each hue. For example, the red color of the input data can be converted into yellow by adjusting the hue, the light blue can be converted into dark blue by adjusting the saturation, or the yellow can be converted into the red while brightening the green.

FIG. 5 is a block diagram showing an example of the structure of the saturation adjuster 4. As shown in FIG. 5, the saturation adjuster 4 has a subtracter 8 for outputting the difference between the input data.
a, 8b and a divider 9 for calculating the ratio of the difference data
, A multiplier 10 for outputting a multiplication value of the adjustment value and the ratio of the difference data, adders 11a and 11b for outputting an addition value of the input data and the adjustment value, and a clip processor 1
2 and.

FIG. 6 is a flow chart showing the procedure of processing in the clip processor 12. [Alpha] i, [beta] i, [gamma] i output from the magnitude comparator 1 is sent to the saturation adjuster 4, and the subtractor 8a, 8b subtracts the difference data [psi] = [alpha] i- [beta].
i, χ = αi−γi is calculated, and the ratio ψ / χ is calculated by the divider 9. Then, the adder 11b adds the saturation adjustment values As and γi, and the multiplier 10 multiplies the ratio of the saturation adjustment values As and the difference data so that the ratio of the difference data is maintained. 11a adds and outputs βi. Since the maximum value is not changed in the saturation adjustment, αi is output as it is. Therefore, the output of the saturation adjuster 4 is α1 = αi, β1 = βi + As * ψ /
χ, γ1 = γi + As.

Further, the clip processor 1 in the saturation adjuster 4
2, when αi, βi, γi, and As are input (S1) as shown in FIG. 6, when γ1 is larger than α1 or when γ1 is underflow, γ1 is changed to α1.
Saturation adjustment value As to clip to or to γ1 to the minimum value "0" that does not cause underflow.
Clip processing is performed on. That is, As and αi-
γi is compared (S2), and when As is larger than αi−γi, the adjusted value γ1 becomes larger than α1. Therefore, As is clipped to α1 by As.
Clip to -γi (S3) and output As (S
6). On the other hand, As is smaller than αi−γi and −γ
If it is smaller than i (S4), γ1 becomes smaller than “0” and an underflow occurs. Therefore, to clip γ1 to “0”, As is clipped to −γi (S4).
5), As is output (S6).

FIG. 7 is a schematic diagram showing the relationship between the saturation and the αβγ signal. As is clear from FIG. 7, by increasing / decreasing the αβγ signal along the straight line shown in FIG. 7, it is possible to adjust the saturation without changing the hue and lightness.

FIG. 8 is a block diagram showing an example of the configuration of the lightness adjuster 5. As shown in FIG. 8, the brightness adjuster 5 includes dividers 13a, 1 for calculating a ratio of input data.
3b, multipliers 14a and 14b for outputting the multiplication value of the adjustment value and the ratio of the input data, and adders 15a, 15b and 15c for outputting the addition value of the input data and the adjustment value.
And a clip processor 16.

FIG. 9 is a flow chart showing the procedure of processing in the clip processor 16. The α1, β1, and γ1 output from the saturation adjuster 4 are sent to the brightness adjuster 5,
The ratio β1 / α1 of α1 and β1 by the dividers 13a and 13b
Then, the ratio γ1 / α1 of α1 and γ1 is calculated. Then, the brightness adjustment value Av and α1 are added by the adder 15a, and the ratios of α1 and β1 and α1 and γ1 are maintained,
Multipliers 14a and 14b multiply the brightness adjustment value Av by the ratio of α1 to β1 and the ratio of α1 to γ1, respectively, and adders 15b and 15c add β1 and γ1 to output the result. Therefore, the output of the brightness adjuster 5 is α2 =
α1 + Av, β2 = β1 + Av * β1 / α1, γ2 = γ
1 + Av * γ1 / α1.

Further, the clip processor 1 in the brightness adjuster 5
6, when α1, β1, γ1, and Av are input (S11) as shown in FIG. 9, when α2 overflows or underflows, α2 is clipped to the maximum value MAX that does not cause overflow, or Clip to the minimum value "0" that does not cause underflow,
Clip processing is performed on the brightness adjustment value Av.

That is, Av is compared with MAX-α1 (S12), and when Av is larger than MAX-α1, the adjusted value α2 becomes larger than MAX, so α2 is clipped to MAX. And Av to MAX
Clip to -α1 (S13) and output Av (S
16). On the other hand, when Av is smaller than MAX-α1 and smaller than −α1, α2 is smaller than “0”. Therefore, to clip α2 to “0”, Av is clipped to −α1. (S15), Av is output (S
16).

FIG. 10 is a schematic diagram showing the relationship between the brightness and the αβγ signal. As is apparent from FIG. 10, by increasing / decreasing the αβγ signal along the straight line shown in FIG. 10, the lightness can be adjusted without changing the hue and the saturation.

FIG. 11 is a block diagram showing an example of the configuration of the hue adjuster 6. As shown in FIG. 11, the hue adjuster 6 includes an adder 17 for outputting the added value of the input value and the adjustment value, and a clip processor 18.

FIG. 12 is a flow chart showing the procedure of processing in the clip processor 18. Α2, β2, γ2 output from the lightness adjuster 5 are sent to the hue adjuster 6, and the adder 17 adds the hue adjustment values Ah and β2,
It is sent to the clip processor 18. If clipping does not occur, the maximum and minimum values do not change, so α2, γ
2 is output as it is, and the output of the hue adjuster 6 is α3 =
α2, β3 = β2 + Ah, and γ3 = γ2.

In the clip processor 18 in the hue adjuster 6, when α1, β1 and γ1 are input (S21) as shown in FIG. 12, the adjusted value β2a = β2 + Ah.
And α2 are compared (S22), and β2a = β2 + Ah is α
If it is greater than 2, clip β2a to α2,
The difference data δ1 = β2a−α2 and α2 between 2a and α2 is subtracted (S23), and α3, β3, and γ3 are output (S26). Therefore, the output is α3 = α2-δ1,
β3 = α2 and γ3 = γ2.

On the other hand, when β2a = β2 + Ah is smaller than α2 and smaller than γ2, β2a is clipped to γ2 and the difference data δ2 = γ2-β2a between γ2 and β2a.
And γ2 are added (S25), and α3, β3, γ3 are output (S26). Therefore, the output is α3 = α
2, β3 = γ2, γ3 = γ2 + δ2.

FIG. 13 is a schematic diagram showing the relationship between the hue and the αβγ signal. As is clear from FIG. 13, by increasing / decreasing the αβγ signal along the straight line shown in FIG. 13, the hue can be adjusted without changing the saturation and the brightness. Finally, α3 and β output from the hue adjuster 6
3 and γ3 are sent to the RGB selector 7, distributed to the original R, G, B data based on the hue code S2 which is the output of the hue determiner 2, and output as data Ro, Go, Bo after color adjustment. To be done.

[0043]

The color adjusting apparatus according to the present invention can perform color adjustment by HSV without performing complicated color space conversion of RGB signals, and realizes simplification of the apparatus and shortening of processing time. can do. Further, since color space conversion is not performed, there is no calculation error, and highly accurate color adjustment can be performed.

Further, the hue judging means of the color adjusting apparatus according to the present invention judges the hue of the input data and sets the adjustment values of the hue, the saturation and the lightness for each hue, so that each hue can be independent. The hue, saturation, and brightness can be adjusted.

Further, the lightness adjusting means of the color adjusting apparatus according to the present invention adjusts the maximum value, the median value and the minimum value while keeping the ratio of the maximum value and the median value and the maximum value and the minimum value constant. It is possible to adjust only the lightness without changing the hue and saturation.

Further, the clipping means included in the lightness adjusting means of the color adjusting apparatus according to the present invention is such that the maximum value, the median value and the minimum value are kept constant while keeping the maximum value and the median value and the ratio of the maximum value and the minimum value constant. By performing the clipping process of (1), even if the maximum value overflows or underflows, it is possible to adjust the brightness without a feeling of strangeness without changing the hue and the saturation.

Further, the saturation adjusting means of the color adjusting device according to the present invention keeps the ratio of the difference data between the maximum value and the median value and the difference data between the maximum value and the minimum value constant without changing the maximum value. On the other hand, by adjusting the median value and the minimum value, it is possible to adjust only the saturation without changing the hue and lightness.

Further, the clipping means included in the saturation adjusting means of the color adjusting apparatus according to the present invention can change the maximum value and the median value difference data and the maximum value and the minimum value difference data without changing the maximum value. Even if the minimum value becomes larger than the underflow or the maximum value by performing the clipping process of the median value and the minimum value while keeping the ratio constant,
It is possible to perform saturation adjustment without changing the hue and the brightness without changing the feeling.

Further, the hue adjusting means of the color adjusting apparatus according to the present invention adjusts only the hue without converting the saturation and lightness by adjusting the median value without changing the maximum value and the minimum value. be able to.

Further, the clipping means included in the hue adjusting means of the color adjusting device according to the present invention clips the median value to the maximum value and clips the median value and the maximum value when the adjusted median value is larger than the maximum value. If the adjusted median value is smaller than the minimum value, the median value is clipped at the minimum value and the difference between the median value and the minimum value is added to the minimum value to obtain the saturation, It is possible to perform hue adjustment without a sense of discomfort without changing the lightness.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a relationship between an identification code S1 and Ri, Gi, Bi corresponding to a maximum value α, a median value β, and a minimum value γ.

FIG. 3 is a schematic diagram showing a state of hue discrimination by a hue discriminator.

FIG. 4 is an explanatory diagram showing a relationship between a hue area determined as a hue code S2, an identification code S1, and difference data ψ and ω.

FIG. 5 is a block diagram showing a configuration of a saturation adjuster.

FIG. 6 is a flowchart showing a procedure of processing in a clip processor included in the saturation adjuster.

FIG. 7 is an explanatory diagram showing a relationship between saturation by a saturation adjuster and a maximum value α, a median value β, and a minimum value γ.

FIG. 8 is a block diagram showing a configuration of a brightness adjuster.

FIG. 9 is a flowchart showing a processing procedure in a clip processor included in the brightness adjuster.

FIG. 10 is an explanatory diagram showing the relationship between the brightness by the brightness adjuster and the maximum value α, the median value β, and the minimum value γ.

FIG. 11 is a block diagram showing a configuration of a hue adjuster.

FIG. 12 is a flowchart showing a procedure of processing in a clip processor included in the hue adjuster.

FIG. 13 is an explanatory diagram showing the relationship between the hue by the hue adjuster and the maximum value α, the median value β, and the minimum value γ.

FIG. 14 is an explanatory diagram showing the basic concept of a conventional color conversion processing device.

FIG. 15 is an explanatory diagram showing the basic concept of a conventional color conversion processing device.

FIG. 16 is an explanatory diagram showing the basic concept of a conventional color conversion processing device.

FIG. 17 is an explanatory diagram showing the basic concept of a conventional color conversion processing device.

[Explanation of symbols]

1 size comparator 2 hue determiner 3 Adjustment value calculator 4 Saturation adjuster 5 Brightness adjuster 6 Hue adjuster 7 RGB selector 8a, 8b Subtractor 9 divider 10 multiplier 11a, 11b adder 12 clip processor 13a, 13b divider 14a, 14b Multiplier 15a, 15b, 15c adder 16 clip processor 17 adder 18 clip processor 51,52,53 Three-dimensional LUT color converter 54 one-dimensional LUT 55 color signal synthesizing means 61 αβ calculator 62 Hue data calculator 63 Polynomial calculator 64 matrix calculator 65 coefficient generator 66 synthesizer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5B057 CA01 CA08 CB01 CB08 CE17                       CE18                 5C066 AA03 CA01 EB01 GA01 HA03                       KD02 KD07 KE02 KE03 KM11                 5C077 MP08 PP14 PP32 PP35 PP37                       PP43 PQ20                 5C079 HB01 HB06 HB12 LB01 NA03

Claims (8)

[Claims] 1. Comparing means for calculating and outputting a maximum value α, a median value β, and a minimum value γ, which are magnitude relationships based on an RGB signal which is input data, and an RGB signal which is the input data. And a hue determination means for determining the hue of the input data using the maximum value α, the median value β, and the minimum value γ output from the comparison means, and an identification code, and from the hue determination means Adjustment value calculation means for outputting the hue adjustment value Ah, the saturation adjustment value As, and the brightness adjustment value Av set for each hue using the output identification code, the maximum value α, and the median value β A brightness adjusting means for adjusting the brightness of the input data using the minimum value γ and the brightness adjustment value Av; the maximum value α, the median value β, the minimum value γ, and the saturation adjustment value. Of the input data using As Saturation adjusting means for adjusting the degree, and hue adjusting means for adjusting the hue of the input data using the maximum value α, the median value β, the minimum value γ, and the hue adjustment value Ah, A color adjusting apparatus comprising: a selecting unit for returning the αβγ signal to the original RGB signal using the maximum value α, the median value β, the minimum value γ, and the identification code. 2. The hue determining means, the RGB value which is the input data and the correspondence between the maximum value α, the median value β, and the minimum value γ output from the comparing means, and the median value β. , The maximum value α, and the minimum value γ
The hue of the input data is determined based on the relative magnitude relationship of the hue adjustment value calculation means, and the adjustment value calculation means determines the hue adjustment value A set for each hue based on the hue determined by the hue determination means.
The color adjusting device according to claim 1, wherein the color adjusting device outputs h, the saturation adjusting value As, and the lightness adjusting value Av. 3. The lightness adjusting means is configured to have the maximum value α, the median value β, the minimum value γ, and the brightness adjustment value Av.
On the basis of the maximum value α and the median value β, the ratio between the maximum value α and the minimum value γ is kept constant, the maximum value α, the median value β, and the brightness adjustment value Av according to the brightness adjustment value Av. And a brightness clip processing unit for adjusting the minimum value γ and adjusting the maximum value α, the median value β, and the minimum value γ so as not to overflow or underflow. The color adjusting device according to claim 1. 4. The lightness clipping processing means, based on the maximum value α, the median value β, the minimum value γ, and the lightness adjustment value Av, the lightness adjustment means performs the maximum value α and the median value. 4. The color adjusting apparatus according to claim 3, further comprising clipping means for detecting a case where β and the minimum value γ are overflow or underflow and clipping the brightness adjustment value Av in advance. 5. The saturation adjusting means includes the maximum value α, the median value β, the minimum value γ, and the saturation adjustment value As.
The maximum value α without changing the maximum value α
And the difference data of the median value β and the ratio of the difference data of the median value β and the minimum value γ are kept constant, the median value β and the minimum value γ are adjusted according to the saturation adjustment value As.
And a saturation clip processing unit for adjusting the median value β and the minimum value γ so that the median value β and the minimum value γ are larger than the maximum value α or do not cause underflow by the adjustment. Color adjustment device. 6. The saturation clip processing means, based on the maximum value α, the median value β, the minimum value γ, and the saturation adjustment value As, the saturation adjustment means outputs the median value β and The color adjustment device according to claim 5, wherein a case where the minimum value γ is larger than the maximum value α or underflow is detected, and the saturation adjustment value As is clipped in advance. 7. The hue adjusting means is configured to set the maximum value α, the median value β, the minimum value γ, and the hue adjustment value Ah.
The median value β is adjusted according to the hue adjustment value Ah without changing the maximum value α and the minimum value γ, and the median value β is larger than the maximum value α or the minimum value by the adjustment. The color adjusting device according to claim 1, further comprising a hue clip processing unit for adjusting the value so as not to be smaller than the value γ. 8. The hue clip processing means, based on the maximum value α, the median value β, and the minimum value γ,
When the median value β is larger than the maximum value α, the median value β is clipped to the maximum value α, and the difference between the median value β and the maximum value α is subtracted from the maximum value α to obtain the median value β. 9. The median value β is clipped to the minimum value γ when is smaller than the minimum value γ, and the difference between the minimum value γ and the median value β is added to the minimum value γ. Color adjustment device.