JPH05244406A - Color adjustment device - Google Patents

Abstract

PURPOSE:To adjust the color selectively with simple configuration by keeping the continuity of the color. CONSTITUTION:A characteristic used to convert a noted color into an object color based on a noted color chromaticity signal set by a noted color chromaticity setting means 2 and representing a center of a color region desired to be converted in a chromaticity plane representing a hue component and a saturation component and on an object color chromaticity signal set by an object color, chromaticity setting means 3 and representing a color after desired conversion is set to a 1st color conversion means 5. Then a weight coefficient decision means 6 decides the weight coefficient in response to a difference between the inputted chromaticity signal and the noted color chromaticity signal set by the noted color chromaticity setting means 2, and a color adjustment arithmetic means 7 decodes an output color signal in response to an output of the weight coefficient decision means 6 based on an output of the 1st color conversion means 5 and the inputted chromaticity signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color printer, a color copying machine, a color TV, and other devices that handle color images, and saves continuity while keeping other colors in the image and only colors within a specific range. The present invention relates to a selective color adjusting device capable of changing the color.

[0002]

2. Description of the Related Art In recent years, image quality of various color image devices has been improved,
With the progress of the intelligent system, the color adjustment function has become indispensable to fully meet the demands of users.

An example of a conventional color adjusting device will be described below with reference to the drawings. FIG. 18 is a block diagram showing a schematic configuration of a conventional color adjusting device. In FIG.
Reference numeral 100 is a color space conversion means for converting the RGB three color separation values from the (R, G, B) system to the uniform color space L ^* a ^* b ^* system via the (X, Y, Z) system, and 101 is the uniform color space. L ^* a ^* b ^*
From the system, it is the polar coordinate system within the L ^* a ^* b ^* coordinate system (H ° ab,
Polar coordinate conversion means for converting to L ^* , C ^* ab) system, 102 is a selective color adjusting means described later, and 103 is a uniform color from the (H ° ab, L ^* , C ^* ab) system which has undergone color adjustment. Space L ^* a ^* b ^*
It is an inverse color space conversion means for converting to the (R, G, B) system via the system and the (X, Y, Z) system.

The selective color adjusting means 102 will be described below. FIG. 19 is an explanatory diagram of a color adjustment target area specifying method.
FIG. 20 is an explanatory diagram of a color adjustment designation method.

Color adjustment is performed in a polar coordinate system using the hue angle H ° ab and the saturation C ^* ab only in the a ^* b ^* plane, that is, in the chromaticity plane. Hue is specified by the central value of hue angle HC (°) and range angle HA
Using (o), the saturation is specified by the center value CC ^* and the spread amount CA.
^The target color area is determined as indicated by the shaded area in FIG. 19 by combining ^* using ^* . Figure 2 shows the direction and amount of color change.
In the coordinate system of H ° ab and C ^* ab like 0, the hue is D in the ± direction.
The hue is rotated by the amount of H (°) and the saturation is expanded / contracted by Kc times, and these two amounts are used as parameters of the color adjustment amount.

When the two quantities are uniformly changed, a specific color in the color space suddenly changes to another color, resulting in discontinuity in the input / output relationship of hue and saturation.
Also, since there are various kinds of input images, the center value and range of the color distribution used to specify the target color area may change, and it cannot be specified accurately.

Therefore, the target color area is designated by using a membership function in a form that allows some ambiguity. According to this method, the continuity of the color space can be secured by weighting the color adjustment amount using the value of the membership function.

If a two-dimensional membership function in the a ^* b ^* plane is given by (Equation 1), selective color adjustment can be formulated as shown by (Equation 2).

[0009]

[Equation 1]

[0010]

[Equation 2]

Here, (H ° ab, C ^* ab) is the color coordinate value before color adjustment, (H ° ab ', C ^* ab') is the color coordinate value after color adjustment, and DH is the hue H °. The rotation angle of ab, Kc is the magnification of the saturation C ^* ab. That is, the color adjustment is the membership function WH (H ° a
b), WC (C ^* ab) and DH, Kc will be uniquely determined.

The operation of the color adjusting device having the above structure will be described below.

First, the color space conversion means 100 converts the three color separation values from the (R, G, B) system to the CIE1976 uniform color space L ^* a ^* b ^* system via the (X, Y, Z) system. .. Then, the polar coordinate system in the L ^* a ^* b ^* coordinate system (H ° a
b, C ^* ab) system is converted by the polar coordinate conversion means 101. This conversion is shown by (Equation 3).

[0014]

[Equation 3]

Therefore, the selective color adjusting means 102 performs the color adjustment using the above-mentioned two-dimensional membership function, and the resulting color coordinate values (H ° ab ', C ^* ab') and L
By converting from ^* to L ^* a ^* b ^* coordinate system and (X, Y, Z) system to (R, G, B) system of three color separation values by the inverse color space conversion means, the color can be selectively It is possible to obtain adjusted color signals ("Journal of the Institute of Image Electronics Engineers," Vol. 18, No. 5, 3
02-312).

[0016]

However, the above-mentioned structure has the following problems.

When more and more selective color adjustment is performed, conversion from the three primary color signals to the uniform color space L ^* a ^* b ^* system, and further the polar coordinate system within the L ^* a ^* b ^* coordinate system (H゜ ab, L ^* , C ^* a
b) Polar coordinate conversion for conversion to the system and Cartesian coordinate conversion for conversion from the color-adjusted (H ° ab, L ^* , C ^* ab) system to the uniform color space L ^* a ^* b ^* system are required. Since these operations are non-linear operations, it is difficult to perform them in real time.

If a lookup table is used to perform these non-linear operations at high speed, a large number of conversion tables are required and the circuit scale becomes large.
Moreover, creating this conversion table is difficult. Further, if this look-up table is used, a large number of bits are required to increase the calculation accuracy of the non-linear calculation, and the circuit scale becomes large.

It is extremely difficult to perform this color adjustment processing by analog processing due to polar coordinate conversion, which is a non-linear conversion, and is not suitable for performing this color adjustment processing on a video signal in real time, for example. There is also.

Further, as shown in (Equation 2), polar coordinates
Increase the calculation accuracy to perform matrix calculation in the system
If so, the uniform color space L before conversion to the polar coordinate system^*
a^*b ^*A large number of bits are required at the time of the system.

Also, with this color adjusting method, the saturation and hue directions can be adjusted, but the brightness direction cannot be adjusted.

In view of the above problems, it is an object of the present invention to provide a color adjusting device having a simple circuit configuration, a small circuit scale, and high calculation accuracy. Further, adjustment in the lightness direction can be easily performed. Further, the present invention provides a color adjustment device capable of performing selective color adjustment which can be processed in real time with respect to a video signal such as a video signal.

[0023]

In order to solve the above-mentioned problems, a color adjusting apparatus of the present invention is a color adjusting apparatus for a color representing two elements of a plane orthogonal Cartesian coordinate system representing a hue component and a saturation component among three attributes of color. A chromaticity signal and a chromaticity signal of interest for setting the chromaticity signal at the center of the color area to be converted by color adjustment, and color adjustment centering on the chromaticity signal of the attention color set by the chromaticity signal of interest Color adjustment area setting means for setting an area on the Cartesian coordinate system, and a chromaticity signal when the chromaticity signal of the attention color set by the attention color chromaticity signal setting means is converted into a desired color. Target color chromaticity signal setting means to be set,
A first color conversion that acts on the entire plane so as to convert the chromaticity signal of the target color into the chromaticity signal of the target color from the output of the target chromaticity signal setting means and the output of the target chromaticity signal setting means. Means, a weighting coefficient determining means for determining a weighting coefficient representing the degree of color adjustment according to the input chromaticity signal, the input chromaticity signal and the chromaticity signal to the first color converting means. The present invention further comprises a first color adjustment calculation means for generating a chromaticity signal between the input chromaticity signal and the output chromaticity signal in accordance with the output of the weighting factor generation means.

A color space conversion means for converting the three primary color signals into a chromaticity signal representing two elements of the orthogonal coordinate system of the plane representing the hue component and the saturation component among the three attributes of the color, and the color space conversion is desired. Attention color color signal setting means for setting the three primary color signals at the center of the color region, and the orthogonal coordinate system for performing color adjustment centering on the chromaticity signal obtained from the attention color color signal set by the attention color color signal setting means. Color adjustment area setting means for setting the above areas, and target color / color signal setting means for setting the three primary color signals when the color signal of the target color set by the target color / color signal setting means is converted into a desired color. When,
From the three primary color signals set by the target color signal setting means and the three primary color signals set by the target color signal setting means, the three primary color signals of the target color are converted into the three primary color signals of the target color. Second color converting means that operates on the entire color space, weighting factor determining means that determines a weighting factor representing the degree of color adjustment according to the input chromaticity signal, and the output of this weighting factor determining means. Second color adjustment for generating three primary color signals between the input three primary color signals and the three primary color signals output when the three primary color signals are input to the second color conversion means. And a calculation means.

Further, the input chroma signal and color adjustment are performed.
Represents the saturation and hue of the target color, which is the center of the desired color range
Target color chroma signal generating means for generating target color chroma signal
And generating the target color chroma signal from the input chroma signal
Means for subtracting the color-of-interest chroma signal generated by the means
And rectifying and smoothing means for rectifying and smoothing the output of the subtracting means
And the output level of this rectifying and smoothing means is below a predetermined level.
Limit means to limit the phase of the input chroma signal
Of the phase shift means for shifting the
Amplifying means for amplifying or attenuating the output with a predetermined gain
Is based on the output of the attenuator and the rectifying and smoothing means.
Performs internal division calculation of the force chroma signal and the output of the amplification means
Third color adjustment calculation means for obtaining a color-adjusted chroma signal;
It is equipped with.

[0026]

According to the present invention having the above-described structure, the target chromaticity signal and the target representing the center of the color region to be converted set by the target chromaticity signal setting means in the chromaticity plane showing the hue component and the saturation component. The first color conversion means has a characteristic that acts on the entire plane so as to convert the target color into the target color from the target color chromaticity signal representing the desired converted color set by the color chromaticity signal setting means. The weighting factor is determined by the weighting factor determining device according to the difference between the chromaticity signal that is set and input and the chromaticity signal of interest that is set by the chromaticity signal of interest setting unit, and the output of the first color conversion unit is determined. And an input chromaticity signal, the output color signal is determined according to the output of the weighting factor determining means.

Further, the chromaticity signal obtained from the three primary color signals indicating the center of the color region to be converted set by the target color signal setting means and the color output from the color space converting means from the input three primary color signals. The weighting factor generating means generates a weighting factor according to the distance in the chromaticity plane indicating the hue component and the saturation component with respect to the intensity signal, and the three primary color signals of the target color are set by the target color signal setting device. Further, it is inputted to the second color conversion means having an input / output characteristic for converting into a desired primary color representing the desired converted color and the three primary color signals, and the output three primary color signals and the input three primary color signals. From the above, the output three primary color signals are determined according to the output of the weighting factor determining means.

Further, the hue of the input color and the target color is subtracted from the input chroma signal by subtracting the hue of the target color to be subjected to color adjustment generated by the target color chroma signal generating means and the target color chroma signal indicating the saturation. And a sine wave representing the difference in saturation are generated, the rectifying and smoothing means rectifies and smoothes this sine wave, and then the limiting means limits the output of the rectifying and smoothing means in the color adjustment range to obtain a weighting factor, and The phase of the input chroma signal is shifted and amplified, and the output chroma signal is obtained from the output after the amplification and the input chroma signal by the output of the rectifying means.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color adjusting apparatus according to a first embodiment of the present invention will be described below with reference to the drawings.

Before describing the operation, the chromaticity signal representing the two elements of the orthogonal coordinate system on the plane representing the hue component and the saturation component of the three attributes of the color described in the present invention will be described. As a chromaticity signal representing two elements of a plane orthogonal coordinate system representing a hue component and a saturation component, a luminance color difference signal (for example, Y, R
-Y, BY signals) color difference signals and luminance chroma signals (Y
C signal), CIE1964 uniform perceptual color space (U ^* V ^* W ^* ) perceptual chromaticity index (U ^* V ^* ), CIE19
76 Perceptual chromaticity index (u ^* ) of uniform perceptual color space (L ^* u ^* v ^* )
v ^*), perception chromaticity index (a ^* b of CIE1976 uniform perceptual color space ^{(L * a * b *)} *), hue H, saturation S of HLS space
And so on. In the present invention, signals representing these are chromaticity signals.

FIG. 1 shows the color tone of the first embodiment of the present invention.
It is a block diagram showing a schematic structure of a leveling device. Figure 1 Smell
, 1 is an input color signal (in this embodiment, an RGB signal
Color space (in this embodiment, CIE 1976 uniform perception)
Color space (L^*u^*v^*) A signal (L^*，
u^*, V^*) Is a color space conversion means. 2 is color
The chromaticity coordinates of the target color in the center of the color area
Chromaticity signal (u₀ ^*, V₀ ^*) Attention color setting
No. 3 is a setting means, and the desired color adjustment is performed on this noticed color.
Chromaticity signal (u_0h ^*，
v_0h ^*) Is a target color chromaticity signal setting means, 4 is a note
Set the color adjustment area where you want to perform color adjustment centering on the eye color.
Color adjustment area setting means. Also, 5 is the color of attention
Signal of the signal setting means 2 (u₀ ^*, V₀ ^*) And the target color chromaticity
Output chromaticity signal (u of signal setting means 3_0h ^*, V_0h ^*) Based on
And attention color chromaticity signal (u₀ ^*, V₀ ^*) From the target color chromaticity signal
(U_0h ^*, V_0h ^*) Transforms the entire plane like
It is the first color conversion means having characteristics. 6 is the input color
Degree signal (u^*, V^*) According to the color adjustment area setting means 5
Weighting coefficient ω that indicates the degree of color adjustment within the specified color adjustment area
Of the color space conversion means 1
Chromaticity signal (u^*, V^*) And the first color conversion means
5 output chromaticity signal (u_h ^*, V_h ^*) And determine the weighting factor
Color input based on the weighting factor ω determined by the means 6
The first color adjustment calculation means for performing color adjustment processing on the degree signal, 8
The chromaticity signal (u of the output of the first color adjustment calculation means 6)_c ^*，
v_c ^*) And the brightness component of the output of the color space conversion means 1
Signal L^*Color signals input from and (in this embodiment,
It is an inverse color space conversion means for converting into an RGB signal).

FIG. 2 is a block diagram of a schematic configuration of the weighting factor determining means 6. Reference numeral 61 is a chromaticity coordinate conversion means for performing coordinate conversion on the chromaticity plane in the uniform color appearance space so that the chromaticity coordinate of the target color becomes the origin on the chromaticity coordinate. The chromaticity signal of interest (u ₀ ^* , v ₀ ^* ) is subtracted from the signal (u ^* , v ^* ). 62 is a color adjustment area (u ₀ ^* + u ₁ ^* , u) set by the color adjustment area setting means 4.
^{_{0 * -u 1 *, v 0}} * + v 1 *, v 0 * -v 1 *) in the color adjustment area coordinate transforming means for performing similarly coordinate transformation, 63 chromaticity of output chromaticity coordinate conversion means 61 signal ^{_{(u * -u 0 *, v}} * -v 0 *) and set in the color adjustment area coordinate converter 62 the color adjustment area ^{_{(u 1 *, -u 1 *}} , v 1 *, -v 1 *) It is a weighting factor generating means for generating the weighting factor ω from

Further, FIG. 3 is an operation explanatory view of the chromaticity coordinate conversion means 61 and the color adjustment area coordinate conversion means 62. As shown in the drawing, the chromaticity signals (u ₀ ^* , v ₀₎ representing the chromaticity coordinates of the target color are shown. ^* )
Coordinate conversion is performed so that is the origin. Note that FIG.
The shaded area of the rectangle shown in (a) shows the color adjustment area set by the color adjustment area setting means 4, and the rectangular area shown in FIG. 3 (b) shows the color converted by the color adjustment area coordinate conversion means 62. This is an adjustment area.

FIG. 4 shows the distribution of the weighting factor ω generated by the weighting factor generating means 63 on the coordinates (FIG. 3) converted by the chromaticity coordinate converting means 61, as shown in the figure. On the converted coordinates, the weighting coefficient ω is the origin of the chromaticity signal (u ^* , v ^* ) input to the chromaticity coordinate conversion means 61, that is, the chromaticity signal (u ₀ ^* , v ₀ ) representing the target color. ^{In the case of *} ), the maximum (ω = 1) is set, and the distance becomes smaller as the distance to the boundary of the region increases, and the weighting factor ω becomes 0 at the boundary.

FIG. 5 shows the first color adjustment calculation means 7.
It is a block diagram showing a schematic structure. In FIG. 5, 71
-A and 71-b are colors in the output of the color space conversion means 1.
Degree signal (u^*, V^*) And 1-ω of the internal division ratio of the weighting coefficient
First and second multipliers 72-u, 72- for multiplying each other
b is a chromaticity signal output from the first color conversion means 5.
(U _h ^*, V_h ^*) And the weighting factor internal division ratio ω
In the third and fourth multipliers, 73-a is the first multiplier.
Output (1-ω) × u^*And the output of the third multiplier ω × u_h ^*When
Is added to the first adder, 73-b is the output of the second multiplier.
Force (1-ω) × v^*And the output of the fourth multiplier ω × v_h ^*And
It is a second adder for adding.

Therefore, the first color adjustment calculation means 7 outputs the chromaticity signals (u ^* , v ^* ) of the output of the color space conversion means 1 and the chromaticity signal (u ^* , v ^* ) output from the first color conversion means 5 ( u _h ^*, v _h ^*)
Are internally divided by the output ω of the weighting factor determining means 6. This operation can be expressed by an equation (4).

[0037]

[Equation 4]

The operation of the first embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3, 4, and 5.

First, the input color signals RGB are converted by the color space conversion means 1 into the CIE1976 uniform perceptual color space (L ^*).
u ^* v ^* ). The conversion formulas at this time are shown in (Equation 5) and (Equation 6).

[0040]

[Equation 5]

[0041]

[Equation 6]

CIE1976 uniform perceptual color space (L ^* u ^* v
^* ) In the above, the perceived chromaticity index (u ^* , v ^* ) represents two elements of the orthogonal coordinate system of the plane representing the hue component and the saturation component. Therefore, if color adjustment is performed in this plane, You can adjust the hue and saturation while maintaining the brightness.
That is, when performing color adjustment while maintaining the brightness, the hue changes by rotating (θ degrees) about the origin in the chromaticity plane (u ^* , v ^* ) as shown in FIG. By multiplying the distance from to a constant multiple (k times), the saturation changes. Therefore, the color adjustment can be performed by the linear conversion shown in (Equation 7).

[0043]

[Equation 7]

At this time, as shown in FIG. 6, the saturation is increased when k is larger than 1, the saturation is not adjusted when k is 1, and the saturation is decreased when k is smaller than 1. Then, when k is set to 0, the color of interest becomes the origin on the chromaticity plane and can be converted into a monochrome image.

When the rotation angle θ is positive, the chromaticity plane rotates counterclockwise, and the red color becomes yellowish, for example, as shown in FIG. 6, and when the rotation angle θ is negative, the chromaticity plane changes. It rotates clockwise and, for example, the green color becomes yellowish as shown in FIG. If the rotation angle θ is 0, the hue does not change as a matter of course. The range of this rotation angle θ is −π ≦ θ ≦ π
Is.

Therefore, in the first color converting means 5, the chromaticity signal (u ₀ ^* , v ₀ ^* ) at the center of the color area to be subjected to the color adjustment set by the noticeable chromaticity signal setting means 2 and the target. From the chromaticity signals (u _0h ^* , v _0h ^* ) of the color to be converted by the color adjustment of the target color set by the color / chromaticity signal setting means 3, the linear conversion shown in (Equation 7) is obtained. With this linear conversion, the entire chromaticity plane is converted.

Now, the color adjustment area setting means 4 will be described. Generally, the area where color adjustment is performed is represented by a fan shape as shown in the conventional example. However, when color adjustment is originally performed, the area must be very small in order to maintain color continuity. Therefore, if the color adjustment area is a minute range, a rectangle is sufficient, and it is not necessary to polarize the chromaticity signals (u ^* , v ^* ) input by determining the area with a rectangle. Since the circuit structure can be simplified, in this embodiment, the area determined by the color adjustment area determining means 4 is represented by chromaticity coordinates (u ₀ ^* , v ₀ ^* ) of the target color as shown in FIG. It is the center rectangle.

Then, in the weighting factor determining means 6, in accordance with the chromaticity signal (u ^* , v ^* ) representing the chromaticity coordinates of the input color, the color of the target color on the chromaticity plane as described above. The weighting factor ω is determined according to the distance from the chromaticity signal (u ₀ ^* , v ₀ ^* ) representing the degree coordinate. The operation of the weighting factor determining means 3 will be described in more detail with reference to FIGS. 2, 3 and 4.

The chromaticity signal (u ^* , v ^* ) input to the weighting factor determining means 6 is first converted by the chromaticity coordinate converting means 61, as shown in FIG. (U
₀ ^*, v ₀ ^*) performs coordinate conversion so that the origin. This is done because it is not necessary to change the contents of the weighting factor generating means 63 when only the target color is changed and the range of the color adjustment area is not changed, and the circuit configuration is simplified.

Then, it is set by the color adjustment area setting means 4.
Color adjustment area (u₀ ^*+ U₁ ^*, U₀ ^*-U ₁ ^*, V₀ ^*+ V₁ ^*, V
₀ ^*-V₁ ^*) Is converted by the color adjustment area coordinate conversion means 62.
Color adjustment area (u₁ ^*, -U₁ ^*, V₁ ^*, -V₁ ^*) (See Figure 4
Based on the hatched area)
Obtain the input / output characteristics. This weighting factor ω is shown in FIG.
Origin, that is, chromaticity to be input on the plane whose coordinates have been converted
Maximum (ω = 1) when the signal is the target color, and close to the boundary of the area.
It decreases continuously as it goes down, and it is the minimum at the boundary (ω = 0)
Set so that This weighting factor generating means 63
Can be easily configured by using a lookup table, for example
it can.

By the weighting factor ω determined by the weighting factor determining means 6 in this way, the chromaticity signals (u ^* , v ^* ) of the output of the color space converting means 1 and the output of the first color converting means 5 are output. From the chromaticity signal (u _h ^* , v _h ^* ) of the above, the chromaticity signal (u _c ^* ) color-adjusted by the calculation shown in (Equation 4), that is, the internal division calculation, by the first color adjustment calculation means 7 ^. , V _c ^* ) is obtained.

FIG. 7 shows an example in which this color adjustment calculation is performed. In this example, the saturation adjustment is not performed, the rotation is performed by + θ degrees in the hue direction, and the input / output characteristics of the weighting factor generating means 63 are those shown in FIG. At this time (Equation 7)
The linear transformation shown by can be expressed by (Equation 8).

[0053]

[Equation 8]

As can be seen from this figure, the chromaticity coordinates after the color adjustment of the noted color change to the chromaticity coordinates calculated based on (Equation 8), and the amount of change decreases as the distance from the noted color increases. It can be seen that the amount of change at the boundary of the adjustment area is zero. Moreover, the color outside the area and the color inside the area are not reversed by the color adjustment.

Thereafter, the inverse color space conversion means 8 is used to
Of the outputs of the inter-conversion means 1, L representing the brightness^*Signal and
Chromaticity signal output from the first color adjustment calculation means 7
(U_c ^*, V_c ^*), And convert it to RGB color signal and adjust the color
The color signal can be obtained.

In the present embodiment, the color space conversion means 1 uses the color signal to convert the CIE1976 uniform perceptual color space (L ^* u).
^* V ^*) it is assumed to be converted to, just mentioned as example CIE1976 uniform perceptual color space from the color signal (L ^* a ^*
b ^* ) and luminance / color difference signals (for example, Y, R)
The same effect can be obtained with a similar configuration even for a conversion such as (-Y, BY signal).

Further, in this embodiment, the weighting factor generating means 6
A chromaticity coordinate conversion means 61 whose origin is the chromaticity signal of the target color
The color adjustment area coordinate conversion means 62 is provided to generate the weighting coefficient ω with the chromaticity signal of the target color as the origin, but the same effect can be obtained by performing the conversion on the chromaticity plane without performing the coordinate conversion.

As described above, in the chromaticity plane showing the hue component and the saturation component, the target color chromaticity signal and the target color color representing the center of the color region to be converted set by the target color chromaticity signal setting means. The characteristic for converting the entire plane so as to convert the target color into the target color from the target color chromaticity signal representing the desired converted color set by the color signal setting means is set in the first color converting means and input. The chromaticity signal of interest and the chromaticity signal of interest set by the chromaticity signal of interest, the weighting factor is determined by the weighting factor determining device, and the output chromaticity signal of the first color conversion device is determined. By determining the output color signal according to the output of the weighting factor determining means from the input chromaticity signal, the color is not reversed between the inside and the outside of the color adjustment region while maintaining the continuity, Selective color adjustment can be performed.

Further, since complicated non-linear conversion processing to the polar coordinate system is unnecessary, the configuration can be made very simple and the circuit scale can be reduced.

Moreover, since the non-linear conversion is only the color space conversion in this color adjustment processing, it can be configured with a relatively small number of bits. In particular, if the color space converted by the color space conversion means is represented by a luminance color difference signal, it is not necessary to carry out a non-linear operation, and it is possible to realize a compact structure capable of processing in real time.

Next, a second embodiment of the present invention will be described. The configuration of the second embodiment is the same as that of FIG. 1, and the first color adjustment calculation means 7 has the configuration shown in FIG. In the present embodiment, the configuration and the operation are the same except for the first color adjustment calculation means 7, and therefore detailed description thereof will be omitted, and only the configuration and the operation of the first color adjustment calculation means 7 will be described.

FIG. 8 shows the first color adjustment calculation means 7 of this embodiment.
74-a and 74-b are chromaticity signals (u _h ^* , 74) of the output of the first color conversion means 5, respectively.
v _h ^*) from the chromaticity signal of the output color space conversion unit 1 (u ^*, v ^*) first and second subtracter for subtracting, 75-
a and 75-b are fifth and sixth multipliers 76-a and 76-, which multiply the outputs of the first and second subtractors by the weighting factor ω.
Reference numerals b are third and fourth adders for adding the outputs of the fifth and sixth multipliers and the chromaticity signals (u ^* , v ^* ) of the outputs of the color space conversion means 1.

The operation of the thus-configured first color adjustment calculation means 7 will be described. From the chromaticity signals (u ^* , v ^* ) of the output of the color space conversion means 1, the first color conversion means is obtained. 5 output chromaticity signals (u _h ^* , v _h ^* ) are respectively subtracted,
Each of these results is multiplied by the weighting coefficient ω determined by the weighting coefficient determining means 6, and the input chromaticity signal (u ^* , v ^* ) is added to each multiplication result to obtain the weighting coefficient ω.
Chromaticity signal (u ^* , v ^* ) input with the internal division ratio determined by
Do an internal division with. After that, the output chromaticity signal can be inversely converted into a color signal, and color adjustment can be selectively performed.

As described above in the present embodiment, the color adjustment calculation means is operated by the chromaticity signal (u _h ^* ,
first and second subtracters for subtracting the chromaticity signals (u ^* , v ^* ) of the output of the color space conversion means 1 from v _h ^* ), and the outputs of these first and second subtractors To the weighting factor ω, and chromaticity signals (u ^* , v ^* ) of the outputs of the fifth and sixth multipliers and the output of the color space conversion means 1. By using the third and fourth adders for adding and, the number of multipliers can be reduced, the circuit scale can be reduced, and particularly analog processing with poor calculation accuracy can be used. Even in such a case, the influence on the calculation result is small, and there is an extremely practical effect.

Further, a third embodiment of the present invention will be described. The configuration of the third embodiment is the same as that of FIG. 1, but only the configuration of the weighting factor determining means 6 is different. FIG. 9 shows the configuration of the weighting factor determining means 6 of this embodiment. In the present embodiment, the configuration and operation thereof other than the weighting factor determining means 6 are the same, so a detailed description is omitted, and only the configuration of the weighting factor determining means 6 and its operation will be described.

FIG. 10 shows the weighting factor determining means 6 of this embodiment.
FIG. In FIG. 9, 61 is a chromaticity signal (u
^*, V^*), A chromaticity signal (u
₀ ^*, V₀ ^*Coordinate conversion so that) is the origin on the chromaticity coordinates.
Chromaticity coordinate conversion means to perform, 62 is color adjustment area setting means 4
Color adjustment area (u₀ ^*+ U ₁ ^*, U₀ ^*-U₁ ^*, V
₀ ^*+ V₁ ^*, V₀ ^*-V₁ ^*) Color adjustment to perform coordinate conversion in the same manner
Area coordinate conversion means 63 is an output of the chromaticity coordinate conversion means 61.
Force u^*-U₀ ^*As an input, the color adjustment area coordinate conversion means 62
The color adjustment area (u₁ ^*, -U₁ ^*) Based on
Weighting factor ω shown in 10 (a)_aFirst weighting factor that outputs
Number generating means, 64 is an output v of the chromaticity coordinate converting means 61^*−
v₀ ^*Is input and converted by the color adjustment area coordinate conversion means 62.
Color adjustment area (v₁ ^*, -V₁ ^*) Based on FIG.
Weighting factor ω shown in (b)_bOutput the second weighting coefficient
And 65 is a first and a second weighting factor generating means 63,
64 output weighting factors ω_a, Ω_bFrom (Equation 9)
The fuzzy logical product is calculated by the min operation shown in FIG.
Fuzzy AND means for outputting the weighting factor ω shown in (c)
Is.

[0067]

[Equation 9]

The operation of this embodiment configured as described above will be described. Since the operation is the same as that of the first embodiment, it will be briefly described. First, the input color signal RGB is converted by the space conversion means 1 into a signal representing the CIE1976 uniform perceptual color space (L ^* u ^* v ^* ). The first color conversion unit 5 obtains a linear conversion for adjusting a color on the chromaticity plane desired to be adjusted in advance to a desired color, and the first color conversion unit 5 inputs the chromaticity. The signal (u ^* , v ^* ) is subjected to linear conversion, and the chromaticity signal (u _h ^* ,
v _h ^* ).

Chromaticity signal input to weighting factor determining means 6
(U^*, V^*) Is first noted by the chromaticity coordinate conversion means 61.
Chromaticity signal of color (u₀ ^*, V₀ ^*) Is the origin
Exchange. Color adjustment set by the color adjustment area setting means 4
Area (u₀ ^*+ U₁ ^*, U₀ ^*-U ₁ ^*, V₀ ^*+ V₁ ^*, V₀ ^*-V
₁ ^*) Is adjusted by the color adjustment area coordinate conversion means 62.
Area (u₁ ^*, -U₁ ^*, V₁ ^*, -V₁ ^*) Based on the first
In the weighting factor generating means 63,
Output u^*-U₀ ^*Is input, and is shown in FIG. 10 (a), for example.
Such a weighting factor ω_aIs output. Also, the second weighting factor
In the generation means 64, the output v of the chromaticity coordinate conversion means 61^*−
v₀ ^*Is input, and the weight as shown in FIG.
Coefficient ω_bIs output. Then, each input signal u^*−
u₀ ^*, V^*-V₀ ^*Weighting factor ω generated for_a, Ω_bOr
From the fuzzy logical product calculation means 65 to the min calculation.
The fuzzy logical product is taken, and the weighting factor shown in FIG.
Output the number ω.

The chromaticity output (u ^* , v ^* ) of the color space conversion means 1 and the output of the first color conversion means 5 (u _h ^* ) are thus determined by the weighting coefficient ω determined by the weighting coefficient determining means 6 ^. ，
From v _h ^* ), the chromaticity signal (u _c ^* , v _c ^* ) color-adjusted by the calculation shown in (Equation 4), that is, internal division, is obtained by the first color adjustment calculation means 7.

Thereafter, the inverse color space conversion means 8 outputs the L ^* signal representing the brightness of the color space conversion means 1 and the chromaticity output (u _c ^* , v _c ^* ) of the first color adjustment calculation means 7. It is possible to generate RGB color signals and obtain color-adjusted color signals.

As described above, with respect to each element axis of the chromaticity signal represented by the two elements of the Cartesian coordinate system of the plane which represents the hue component and the saturation component, which is inputted to the weighting factor generating means, the respective axes are on-axis. The weighting coefficient of 1 is 1, and the weighting coefficient decreases continuously with distance from the axis, and the weighting coefficient of 0 is generated at the boundary parallel to each axis of the color adjustment area determined by the color adjustment area determination means. The input / output characteristic of the weighting coefficient determining means is one-dimensional by comprising the coefficient determining means and the fuzzy logical product calculating means for generating the weighting coefficient by the fuzzy logical product of the outputs of the two weighting coefficient determining means. In addition, since the fuzzy AND operation means is also simple in construction, there is an effect that the input / output characteristics can be more easily determined.

Next, a color adjusting apparatus according to a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 11 is a block diagram showing the schematic arrangement of a color adjusting apparatus according to the fourth embodiment of the present invention. In FIG. 11, reference numeral 1 is the input three primary color signals (R in this embodiment).
A GB signal) is used as a uniform color space (CIE1 in this embodiment).
976 Colors to be converted into chromaticity signals (u ^* , v ^* ) indicating two elements of a plane orthogonal coordinate system representing a saturation component and a hue component in a uniform perceptual color space (L ^* u ^* v ^* ) It is a space conversion means.
9 is the target color 3 at the center of the color area to be converted by color adjustment.
Reference color color signal setting means for setting the primary color signals (R ₀ , G ₀ , B ₀ ) is a three-primary color signal (R _0h , R _0h , after the color adjustment when the desired color adjustment is performed on the target color. G _0h , B _0h ) target color signal setting means 4 is a color adjustment area setting means for setting a color adjustment area to be subjected to color adjustment centering on the target color, and the color adjustment area setting means 4 sets The adjusted color adjustment area is set on the plane representing the hue component and the saturation component. Reference numeral 11 denotes the three primary color signals (R ₀ , G ₀ , B ₀ ) set by the noticeable color signal setting means 9 and the three primary color signals (R _0h , G set by the target color signal setting means 10).
_0h , B _0h ) based on the _target color signal (R ₀ , G ₀ , B ₀ )
Is a second color conversion means for converting the entire color space so as to convert the target color signal (R _0h , G _0h , B _0h ), and 6 from the input three primary color signals (R, G, B) Color space conversion means 1
Weighting coefficient determining means for determining a weighting coefficient ω indicating the degree of color adjustment within the color adjustment area set by the color adjustment area setting means 4 according to the chromaticity signal (u ^* , v ^* ) obtained in step 12; Is a weighting coefficient ω determined by the weighting coefficient determining means 6 from the input three primary color signals (R, G, B) and the output color signals (R _h , G _h , B _h ) of the second color converting means 11. Entered according to 3
It is a second color adjustment calculation means for performing color adjustment processing on the primary color signals and outputting the color-adjusted three primary color signals (R _c , G _c , B _c ).

The block of the weighting factor determining means 6 shown in FIG.
The schematic configuration of the color is the same as that of Fig.
Chromaticity that performs coordinate conversion so that the mark is the origin on the chromaticity coordinates
It is set by the coordinate conversion means 61 and the color adjustment area setting means 4.
Color adjustment area (u₀ ^*+ U₁ ^*, U ₀ ^*-U₁ ^*, V₀ ^*+ V₁ ^*, V
₀ ^*-V₁ ^*Color adjustment area coordinate conversion
Chromaticity signal output from the means 62 and chromaticity coordinate conversion means 61
(U^*-U₀ ^*, V^*-V₀ ^*) And color adjustment area coordinate conversion means 6
Color adjustment area (u₁ ^*, -U₁ ^*, V₁ ^*、-
v₁ ^*) And a weighting factor generating means 6 for generating a weighting factor ω from
3 and comprises a chromaticity coordinate conversion means 61 and a color adjustment area.
The operation of the coordinate conversion means 62 is similar to that of the first embodiment.
It Further, the weight generated by the weight coefficient generating means 63
The coefficient ω on the coordinates converted by the chromaticity coordinate conversion means 61
The distribution is the same as in Fig. 4, and the weighting factor ω is the transformed coordinate.
Chromaticity signal input to chromaticity coordinate conversion means 61 on the elevation
(U^*, V^*) Is the origin, that is, the chromaticity signal that represents the target color
(U₀ ^*, V₀ ^*), The maximum (ω = 1), to the boundary of the region
It becomes smaller continuously with the distance, and the weighting factor ω at the boundary.
Is set to 0.

Further, FIG. 12 shows the second color adjustment calculation means 12
3 is a block diagram showing a schematic configuration of FIG. In FIG. 5, 1
21-a, 121-b, and 121-c are first, second, and third which respectively multiply the input three primary color signals (R, G, B) and 1-ω of the internal division ratio of the weighting coefficient. 3 multiplier, 122
-A, 122-b, 122-c Fourth output color signal (R _h , G _h , B _h ) of the second color conversion means 11 is multiplied by the internal division ratio ω of the weighting factor. In the fifth and sixth multipliers, 123-a is the output of the first multiplier (1-ω) × R
And an output ω × R _h of the fourth multiplier, a first adder 123-b is an output (1-ω) × G of the second multiplier and an output ω × G of the fifth multiplier. a second adder for adding _h and
123-c is the output of the third multiplier (1-ω) × B and the sixth
It is a third adder for adding the output ω × B _h of the multiplier of.

Therefore, the second color adjustment calculation means 12 inputs the three primary color signals (R, G, B) and the color signals output from the second color conversion means 11 (R _h , G _h , B). _h ) is internally divided by the output ω of the weighting factor determining means 6. This operation can be expressed by an equation (10).

[0078]

[Equation 10]

Next, the operation of the fourth embodiment of the present invention will be described with reference to FIGS.

First, the input three primary color signals (G, R,
From B), the color space conversion means 1 converts two elements of a plane orthogonal coordinate system representing the saturation component and the hue component of the CIE1976 uniform perceptual color space (L ^* u ^* v ^* ), as in the first embodiment. The chromaticity signal (u ^* , v ^* ) that it represents is determined.

From the chromaticity signal at the center of the color region to be converted by color adjustment, that is, from the three primary color signals (R ₀ , G ₀ , B ₀ ) of the target color set by the target color color signal setting means 9, (Equation 5) ) And (Equation 6), the chromaticity signal (u ₀ ^* , v ₀ ^* ) of the target color can be easily obtained, so that the coordinates on the chromaticity plane set by the color adjustment area setting means 4 can be easily set. it can.

Further, in the second color conversion means 11, the target color is
A color region to be subjected to color adjustment set by the color signal setting means 9.
The color of interest at the center of the color signal (R₀, G₀, B₀) And the target color
Convert the target color set by the signal setting means 3 by color adjustment
Color signal (R_0h, G _0h, B_0h) And from (Equation 1
The linear transformation shown in 1) is obtained.

[0083]

[Equation 11]

In the linear conversion matrix shown in (Equation 11), the sum of each row becomes 1 in order to equalize the input and output brightness of the input three primary color signals and the output three primary color signals. To ask.

The color adjustment area set by the color adjustment area setting means 4 is the same as that of the first embodiment as shown in FIG.

In the weighting factor determining means 6, the chromaticity signal (u ^* , u ^* , which represents the chromaticity coordinates obtained by the color space converting means 1 from the input three primary color chrominance signals (R, G, B).
v ^*) and chroma signals representing noticeable color chromaticity coordinates on the chromaticity plane described above (u ₀ ^*, v determines a weighting factor ω in accordance with the distance between ₀ ^*).

Further, the operation of the weighting factor determining means 6 is similar to that of the first embodiment, and therefore its explanation is omitted. By the weighting factor ω determined by the weighting factor determining means 6,
From the input three primary color signals (R, G, B) and the three primary color signals (R _h , G _h , B _h ) output from the second color conversion means 11, the second color adjustment calculation means 12 As a result, the three primary color signals (R _c , G _c , B _c ) color-adjusted by the calculation shown in (Equation 10), that is, the internal division calculation, are obtained.

In this embodiment, the color space conversion means 1 converts the three primary color signals (R, G, B) into the chromaticity signals (u ^* , u ^* , ^* ) on the CIE1976 uniform perceptual color space (L ^* u ^* v ^* ). v ^* ) is converted, but as described above, for example, the three primary color signals are converted to chromaticity signals (a ^* , b ^* ) in the CIE1976 uniform perceptual color space (L ^* a ^* b ^* ). The same effect can be obtained with a similar configuration even for a device that performs conversion such as a color difference signal (for example, RY, BY signal).

Also in this embodiment, as in the first embodiment, the weighting factor determining means 6 is provided with the color coordinate converting means 61 and the color adjusting area coordinate converting means 62 having the chromaticity signal of the target color as the origin. The weighting factor ω is generated with the chromaticity signal of the color as the origin, but it is natural that the same effect can be obtained by performing the conversion on the chromaticity plane without performing the coordinate conversion.

As described above, 3 indicating the center of the color region to be converted which is set by the noticed color signal setting means 3
In accordance with the distance on the chromaticity plane indicating the hue component and the saturation component between the chromaticity signal obtained from the primary color signal and the chromaticity signal obtained from the input three primary color signals by the color space conversion means. Input / output for generating a weighting factor by the weighting factor generating means and converting the three primary color signals of the target color into the three primary color signals of the target color representing the desired converted color set by the target color signal setting means. By determining the output three primary color signals according to the output of the weighting factor determination means from the output when the color conversion means having the characteristics and the input three primary color signals, the brightness is continuously changed without changing the brightness. It is possible to perform selective color adjustment without preserving the color between the inside and the outside of the color adjustment area while preserving the property.

Further, since complicated non-linear conversion processing to the polar coordinate system is unnecessary, the configuration can be made very simple and the circuit scale can be reduced. Moreover, since the non-linear conversion is only the color space conversion in the color adjustment processing, the color adjustment processing can be configured with a relatively small number of bits.

Further, in particular, the color space converting means converts the three primary color signals (R, G, B) to the color difference signals (RY, BY).
If it outputs, it is not necessary to perform a non-linear operation, and it is possible to have a small-sized and real-time processing configuration.

Then, the second color conversion means 11 of the present embodiment.
Was performed by a linear operation of 3 rows and 3 columns, and the sum of each row was set to 1 in order to preserve the white balance between the input and output.
If the sum of each row is set to be k (where 0 <k),
The brightness direction can be selectively adjusted. This is because the lightness index L ^*, which is an element expressing brightness in (Equation 6), is determined only by Y as is clear from (Equation 5), and this Y is k times the color signals (R, G, B). By doing so, Y is also multiplied by k. At this time, if k <1, the brightness decreases, when k = 1, the brightness does not change, and when k <1, the brightness increases.

[0094] Thus the three primary color signals of the output of the second color conversion unit 11 at this time _{(Rk h, Gk h, Bk} h) if (number 10) is shown by equation (12), omega = when one, i.e. three primary color signal after color adjustment when the three primary color signals of the input (R, G, B) is noticeable color three primary color signals of (Rk _h, Gk _h, B
k _h ), and becomes a three primary color signal multiplied by k in the lightness direction. When ω = 0, that is, the input three primary color signals (R,
G, B) is on the boundary of the color adjustment region, the output of the second color adjustment calculation means 12 becomes the input three primary color signals (R, G, B).

[0095]

[Equation 12]

Next, a fifth embodiment of the present invention will be described. The configuration of the fifth embodiment is the same as that of FIG. 11, and the second color adjustment calculation means 12 has the configuration shown in FIG. In the second embodiment, the configuration and operation other than the second color adjustment calculation means 12 are the same, so detailed description will be omitted, and only the configuration and operation of the second color adjustment calculation means 12 will be described. To do.

FIG. 13 is a block diagram showing the arrangement of the second color adjustment calculation means 12 of the second embodiment, which is 124-a, 124.
-B, 124-c is a first subtracting the second three primary color signals of the output of the color converter _{11 (R h, G h,} B h) 3 primary color signals input from the (R, G, B) , The second and third subtractors 125-a, 125-b, 125-c are the first and second subtractors.
And the seventh, eighth and ninth multipliers 126-a, 126- for multiplying the output of the third subtractor by the weighting factor ω
Reference numerals b, 126-c denote fourth, fifth and sixth adders for adding the outputs of the seventh, eighth and ninth multipliers and the input three primary color signals (R, G, B). ..

The operation of the second color adjustment calculation means 12 thus configured will be described. The three primary color signals (R _h , G _h , B _h ) of the output of the second color conversion means 11 are subtracted from the input three primary color signals (R, G, B), and the weighting coefficient determining means is applied to the results. 6 is multiplied by each of the weighting factors ω, the input three primary color signals (R, G, B) are added to the respective multiplication results, and the input three primary colors are obtained by the internal division ratio determined by the weighting factor ω. By performing internal division with the color signals (R, G, B), it is possible to selectively perform color adjustment.

As described above in the fifth embodiment, the second color adjustment calculation means 12 outputs the three primary color signals (R _h , G _h , B _h ) output from the second color conversion means 11. From which the input three primary color signals (R, G, B) are subtracted, and the weighting factor ω is applied to the outputs of the first, second and third subtractors. A seventh, an eighth, and a ninth multiplier for multiplication, and a fourth for adding the outputs of the seventh, eighth, and ninth multipliers and the input three primary color signals (R, G, B) , And the fifth and sixth adders, the number of multipliers can be small, the circuit scale can be reduced, and even in the case of analog processing with poor calculation accuracy, It has only a small effect on the calculation result and has an extremely practical effect.

Next, a sixth embodiment of the present invention will be described. FIG. 14 is a block diagram illustrating a schematic configuration of the color adjusting apparatus of this embodiment. In FIG. 14, 13 is a color-of-interest chroma signal generating means, which generates a color-of-interest chroma signal representing the hue and saturation of the color of interest, which is the center of the range for color adjustment. In this embodiment, for example, the phase of the color burst signal included in the NTSC video signal is changed by the phase shift means 13.
The phase is shifted by 1 and its output is amplified by the first amplifier 132 to generate a target color chroma signal representing the hue and saturation of the target color to be color-adjusted. The target color chroma signal is subtracted from the input chroma signal by the subtractor 14 to generate a sine wave (hereinafter, referred to as a difference chroma signal) representing a difference in hue and saturation between the input color and the target color. A rectifying / smoothing means 15 rectifies and smoothes the output of the subtracting means 14,
Is a limiting means for limiting the output level of the rectifying / smoothing means 11 to a predetermined level or lower, and the output of the limiting means is normalized to the predetermined level. Reference numeral 17 is a phase shift means for shifting the phase of the input chroma signal, and 18 is a second amplifier for amplifying the amplitude of the phase-shifted input chroma signal. Reference numeral 19 denotes a chroma adjusted based on the output of the limiter 16 from an input chroma signal and a chroma signal phase-shifted and amplified by the phase shifter 17 and the second amplifier 18 (hereinafter referred to as a converted chroma signal). It is a third color adjustment calculation means for obtaining a signal.

The operation of the color adjusting apparatus of this embodiment having the above-described structure will be described with reference to FIGS. 14 and 15.

FIG. 15 is a waveform diagram showing the waveform of each part shown in FIG. 14 of this embodiment, and FIG. 16 is a vector representation thereof.

First, in the target color chroma signal generation means 13, the reference color burst signal shown in FIG. 15A is input to the phase shift means 131 and phase-shifted to the phase angle representing the hue of the target color. Then, the second amplifying means 132 amplifies the chroma representing the saturation of the target color with the gain G _B to generate the target color chroma signal (the waveform shown in FIG. 15B and the vector shown in FIG. 16B). To do.

Then, the subtractor 14 subtracts the target color chroma signal from the input chroma signal (FIG. 16 (c)) shown in FIG. 15 (c) to obtain the difference chroma signal (FIG. 15 (d)). 16 (d)) is generated. This difference chroma signal is
The difference between the target color and the input color, that is, the difference between the hue and the saturation is shown.

This difference chroma signal is input to the rectifying / smoothing means 15 to perform rectifying / smoothing. This rectified and smoothed waveform is shown in Fig. 1.
5 (e). This rectified and smoothed output signal is shown in FIG.
As shown in (d), it represents the distance between the target color (b) and the input color (c) on the color difference plane (RY, BY plane).

Next, the output (e) of the rectifying / smoothing means 15 is
It is input to the limit means 16. This limit means 16
Is level-limited at a predetermined level (hereinafter referred to as a threshold value). This threshold indicates the circle shown in FIG. 16, and sets an area to be subjected to color adjustment centering on the target color. Then, the output of the level-limited rectifying / smoothing means 15 is normalized by a threshold value. That is, the output of the limiter 16 is as shown in FIG. 17, which has a maximum value outside the boundary of the color adjustment area and outside the color adjustment area, and has a minimum value for the color of interest. indicates ω.

On the basis of the weighting factor ω thus determined, the third color adjustment calculation means 19 performs the internal division calculation of the input chroma signal and the converted chroma signal to obtain the color-adjusted chroma signal. be able to. This internal division calculation can be expressed by a mathematical expression (Equation 13). In (Equation 13), c _(c) is an input chroma signal, c _(f) is a converted chroma signal, and c _(g) is a color-adjusted chroma signal.

[0108]

[Equation 13]

As described above, in this embodiment, the target color and the target color chroma signal representing the hue and saturation of the target color to be subjected to the color adjustment generated by the target color chroma signal generating means 6 from the input chroma signal are generated. A sine wave representing the difference in hue and saturation between the input color and the target color is generated by subtraction, this sine wave is rectified and smoothed by the rectifying and smoothing means, and then the output of the rectifying and smoothing means is adjusted by the limit means in the color adjustment range. By limiting, the weighting coefficient corresponding to the color difference between the input color and the target color is obtained, the phase of the input chroma signal is shifted and amplified based on this weighting coefficient, and the output after the amplification and the A color-adjusted chroma signal is obtained by performing an internal division operation in the color adjustment operation means from the input chroma signal.
It is possible to selectively perform color adjustment only on an arbitrary area while maintaining continuity with colors other than the area.

Further, since complicated non-linear calculation is unnecessary and processing can be performed with the luminance chroma signal as it is, it can be realized with a very simple structure.

Furthermore, since all the processing can be easily performed by analog processing, real-time processing can be performed on video signals such as video signals.

[0112]

As described above, according to the present invention, the chromaticity signal representing two elements of the orthogonal coordinate system of the plane representing the hue component and the saturation component among the three attributes of the color and the chromaticity signal to be converted by the color adjustment. A target color chromaticity signal setting means for setting a chromaticity signal at the center of the color area, and a color adjustment area for setting an area for performing color adjustment centering on the chromaticity signal of the target color set by the target color chromaticity signal setting means. Setting means, target chromaticity signal setting means for setting a chromaticity signal of a desired color after conversion of the chromaticity signal set by the noted chromaticity signal setting means, and output of the noted chromaticity signal setting means And the output of the target chromaticity signal setting means, the first color conversion means acting on the entire plane so as to convert the chromaticity signal of the target color into the chromaticity signal of the target color, and the input chromaticity signal. The weighting factor that indicates the degree of color adjustment according to Means for determining the chromaticity signal between the input chromaticity signal and the chromaticity signal output when the chromaticity signal is input to the first color conversion means. By providing a color adjustment calculation means that is generated in accordance with the output of the color adjustment, selective color adjustment can be performed without the colors being reversed between the inside and the outside of the color adjustment area while maintaining the continuity. it can.

Further, according to the present invention, there is provided a color space conversion means for converting the three primary color signals into a chromaticity signal representing two elements of a plane orthogonal coordinate system representing a hue component and a saturation component among three attributes of color, and a color space converting means. Color adjustment is performed with the target color color signal setting means for setting the three primary color signals at the center of the color region to be converted by adjustment and the chromaticity signal obtained from the target color color signal set by the target color color signal setting means as the center. Color adjustment area setting means for setting an area on the Cartesian coordinate system, and target color color signals for setting the three primary color signals of the desired colors after the attention color color signals set by the attention color color signal setting means are converted. From the setting means, the three primary color signals set by the target color color signal setting means and the three primary color signals set by the target color color signal setting means, the three primary color signals of the target color are converted into the three primary color signals of the target color. To convert to A color conversion unit that operates on the entire color space, a weighting factor determination unit that determines a weighting factor representing the degree of color adjustment according to the input chromaticity signal, and an input according to the output of this weighting factor determination unit. Continuity is provided by providing color adjustment calculation means for generating the three primary color signals between the three primary color signals and the three primary color signals output when the three primary color signals are input to the color conversion means. Save it,
It is possible to perform selective color adjustment without the colors being reversed between inside and outside the color adjustment area.

Therefore, since complicated non-linear conversion processing to the polar coordinate system is unnecessary, the configuration can be made very simple and the circuit scale can be reduced.

In addition, since the non-linear conversion is only the color space conversion in this color adjustment processing, it can be configured with a relatively small number of bits. In particular, if the color space converted by the color space conversion means is represented by a luminance color difference signal, it is not necessary to carry out a non-linear operation, and it is possible to realize a compact structure capable of processing in real time.

Further, since the color conversion means is performed based on the three primary color signals, there is an effect that the lightness can be easily adjusted in addition to the saturation and the hue.

Then, the input chroma signal, the target color chroma signal generating means for generating the target color chroma signal representing the saturation and hue of the target color to be subjected to color adjustment, and the subtraction for subtracting the target color chroma signal from the input chroma signal. Means, rectifying and smoothing means for rectifying and smoothing the output of the subtracting means, limit means for limiting the output of the rectifying and smoothing means, and phase shift means for shifting the output of the limiting means by the phase of the input chroma signal, By providing amplification means for amplifying the gain of the output of the phase shift means, and color adjustment calculation means for obtaining an output chroma signal from the input chroma signal and the output of the amplification means according to the output of the rectifying and smoothing means. With a simple configuration, it is possible to selectively perform color adjustment only on an arbitrary area while maintaining continuity with colors other than the area.

Further, since all the processing can be easily performed by analog processing, the processing can be performed in real time. Then, all processing can be performed with the luminance chroma signal as it is.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a color adjusting apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a weighting factor determining means in the embodiment.

FIG. 3 is an operation explanatory diagram of chromaticity coordinate conversion means in the embodiment.

FIG. 4 is an input / output characteristic diagram of the weighting factor generating means in the embodiment.

FIG. 5 is a block diagram showing the configuration of a color adjustment calculation means in the embodiment.

FIG. 6 is an explanatory diagram of a color adjusting method of the color adjusting apparatus in the embodiment.

FIG. 7 is an operation explanatory view of the color adjusting apparatus in the embodiment.

FIG. 8 is a block diagram showing a configuration of a color adjustment calculation means of a color adjustment device according to a second embodiment of the present invention.

FIG. 9 is a block diagram showing the configuration of a weighting factor determining means of the color adjusting apparatus according to the third embodiment of the present invention.

FIG. 10 is an operation explanatory view of the weighting factor determining means in the embodiment.

FIG. 11 is a block diagram showing a configuration of a color adjusting device according to a fourth embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a second color adjustment calculation means of the color adjustment apparatus in the embodiment.

FIG. 13 is a block diagram showing the configuration of a second color adjustment calculation means of the color adjustment apparatus in the fifth embodiment of the present invention.

FIG. 14 is a block diagram showing the arrangement of a color adjusting apparatus according to the sixth embodiment of the present invention.

FIG. 15 is a waveform diagram showing waveforms of respective parts of the color adjusting apparatus in the embodiment.

FIG. 16 is an operation explanatory diagram of the color adjusting apparatus in the embodiment.

FIG. 17 is an output waveform chart of the limiting means in the embodiment.

FIG. 18 is a block diagram showing a schematic configuration of a conventional color adjustment device.

FIG. 19 is an explanatory diagram of a color adjustment target area specifying method in a conventional color adjusting apparatus.

FIG. 20 is an explanatory diagram of a color adjustment designation method in a conventional color adjustment device.

[Explanation of symbols]

 1 Color space conversion means 2 Target color chromaticity signal setting means 3 Target color chromaticity signal setting means 4 Color adjustment area setting means 5 First color conversion means 6 Weighting factor determination means 7 First color adjustment calculation means 8 Inverse color space conversion Means 9 Target color signal setting means 10 Target color signal setting means 11 Second color converting means 12 Second color adjustment calculating means 13 Target color chroma signal generating means 14 Subtractor 15 Rectifying and smoothing means 16 Limiting means 17 Phase shifting means 18 Amplifier 19 Third color adjustment calculation means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/46 9068-5C // G06F 9/44 330 W 9193-5B

Claims (14)

[Claims] 1. A chromaticity signal representing two elements of a Cartesian coordinate system of a plane representing a hue component and a saturation component among three attributes of color and a chromaticity signal at the center of a color region to be converted by color adjustment are set. Attention color chromaticity signal setting means, and color adjustment area setting means for setting an area on the Cartesian coordinate system for performing color adjustment centering on the chromaticity signal of the attention color set by the attention color chromaticity signal setting means, A target chromaticity signal setting means for setting a chromaticity signal when the chromaticity signal of the attention color set by the attention color chromaticity signal setting means is converted into a desired color; and an output of the attention color chromaticity signal setting means. First color conversion means that acts on the entire plane so as to convert the chromaticity signal of the target color from the output of the target chromaticity signal setting means into the chromaticity signal of the target color,
Weighting factor determining means for determining a weighting factor representing the degree of color adjustment in accordance with the input chromaticity signal, the input chromaticity signal, and when the chromaticity signal is input to the first color converting means. A color adjusting device for generating a chromaticity signal between the chromaticity signal and the output chromaticity signal according to the output of the weighting factor generating means. 2. The color adjusting apparatus according to claim 1, further comprising a color space conversion means for converting the color signal into coordinates on a uniform color space, and using the perceived chromaticity index as the chromaticity signal. 3. A color adjusting apparatus according to claim 1, further comprising a color space converting means for converting a color signal into a luminance signal and a color difference signal, and using the color difference signal as a chromaticity signal. 4. The first color conversion means is a linear system of 2 rows and 2 columns with respect to a chromaticity signal represented by two elements of an orthogonal coordinate system of a hue component and a saturation component to which the input / output characteristics are input. Represented by a conversion,
4. The first color adjustment calculation means performs a linear calculation on the input chromaticity signal and the output of the first color conversion means according to the output of the weighting factor determination means. The described color adjusting device. 5. A first color adjustment calculation means, subtraction means for subtracting an output of the first color conversion means from an input chromaticity signal, a weight coefficient output by the weight coefficient determination means, and the 5. A color according to claim 1, 2, 3 or 4, characterized in that it comprises multiplication means for multiplying the output of the subtraction means and addition means for adding the output of the multiplication means and the input chromaticity signal. Adjustment device. 6. A color space conversion means for converting a three primary color signal into a chromaticity signal representing two elements of a rectangular coordinate system of a plane representing a hue component and a saturation component among three attributes of color, and a color space converting means. A target color color signal setting means for setting the three primary color signals at the center of the desired color area, and the orthogonal coordinates for performing color adjustment centering on the chromaticity signal obtained from the target color color signal set by the target color color signal setting means. Color adjustment area setting means for setting areas on the system, and target color / color signal setting for setting the three primary color signals when the color signal of the target color set by the target color / color signal setting means is converted into a desired color. Means and the three primary color signals set by the target color signal setting means and the three primary color signals set by the target color signal setting means, the three primary color signals of the target color are converted into the three primary color signals of the target color. Color space to convert A second color converting means, a weighting factor determining means for determining a weighting factor representing the degree of color adjustment according to the input chromaticity signal, and an input according to the output of the weighting factor determining means. 3 primary color signals and 3 of the outputs when these 3 primary color signals are input to the color conversion means.
A color adjusting apparatus comprising: a second color adjusting arithmetic means for generating three primary color signals between the primary color signals. 7. The color adjusting apparatus according to claim 6, wherein the color space converting means generates a perceived chromaticity index in the uniform color space from the three primary color signals as a chromaticity signal. 8. The color space conversion means generates a color difference signal as a chromaticity signal from the three primary color signals.
The described color adjusting device. 9. The second color conversion means represents the input / output characteristics of the inputted three primary color signals by linear conversion of three rows and three columns, and the second color adjustment calculation means receives the input. 9. The linear operation of the three primary color signals and the three primary color signals of the output of the second color conversion means is performed in accordance with the output of the weighting factor determination means. Color adjustment device. 10. The second color adjustment calculation means receives the input 3
Subtraction means for subtracting the three primary color signals output from the second color conversion means from the primary color signals, and multiplication means for multiplying the weight coefficient output by the weight coefficient determination means by the output of the subtraction means, 10. The color adjusting apparatus according to claim 6, further comprising an adding unit that adds the output of the multiplying unit and the input three primary color signals. 11. A weighting factor determining means sets an input chromaticity signal by the noted chromaticity signal setting means on a chromaticity plane represented by two elements of an orthogonal coordinate system of a plane representing a hue component and a saturation component. Chromaticity coordinate conversion means for converting a chromaticity signal to be set or a chromaticity signal obtained from the three primary color signals set by the noted color signal setting means into a coordinate system having an origin, and the color adjustment area setting means. The color adjustment area coordinate conversion means for performing the coordinate conversion of the color adjustment area set by the same as the chromaticity coordinate conversion means, and the chromaticity coordinate conversion means within the area determined by the color adjustment area coordinate conversion means. And a weighting factor generating means for generating a weighting factor which is 1 at the origin of the chromaticity coordinates that are continuously reduced according to the distance from the origin and becomes 0 at the boundary of the color adjustment region. Claims 1, 4, 5 6,9 or 10 color adjusting apparatus according. 12. The weighting factor determining means sets an input chromaticity signal by the target chromaticity signal setting means on a chromaticity plane represented by two elements of an orthogonal coordinate system of a plane representing a hue component and a saturation component. Chromaticity coordinate conversion means for converting a chromaticity signal to be set or a chromaticity signal obtained from the three primary color signals set by the noted color signal setting means into a coordinate system having an origin, and the color adjustment area setting means. It is represented by two elements of a color adjustment area coordinate conversion means for performing the coordinate conversion of the color adjustment area set in the same manner as the chromaticity coordinate conversion means, and a plane orthogonal coordinate system coordinate-converted by the chromaticity coordinate conversion means. With respect to each element axis of the chromaticity signal, the boundary has a weighting factor of 1 on the axis, decreases continuously with distance from the axis, and is perpendicular to each axis of the color adjustment area determined by the color adjustment area determination means. Emits a weighting factor that is 0 at And a fuzzy logical product calculating means for generating a weighting coefficient by fuzzy logical product of outputs of the two weighting coefficient determining means. 4, 5, 6,
9. The color adjusting device according to 9 or 10. 13. An input chroma signal, a target color chroma signal generating means for generating a target color chroma signal representing the saturation and hue of the target color which is the center of a color region to be subjected to color adjustment, and from the input chroma signal. Subtracting means for subtracting the target color chroma signal generated by the target color chroma signal generating means, rectifying and smoothing means for rectifying and smoothing the output of the subtracting means, and limiting the output level of the rectifying and smoothing means to a predetermined level or less. Based on the output of the rectifying / smoothing means, the limiting means, the phase shifting means for shifting the phase of the input chroma signal, the amplifying means or the attenuating means for amplifying or attenuating the output of the phase shifting means with a predetermined gain. A third color adjustment calculation means for obtaining a color-adjusted chroma signal by performing an internal division calculation of the input chroma signal and the output of the amplifying means. Adjusting device. 14. The color adjusting apparatus according to claim 1, wherein the color adjusting area set by the color adjusting area setting means is rectangular in the chromaticity plane.