JPH07131806A - Color correcting device - Google Patents

Abstract

PURPOSE:To correct colors with high precision and a high degree of freedom by using small memory capacity by deciding whether or not a signal of each component of a color video signal is an object of color correction and correcting the colors of respective color components when all the color components are objects of color correction. CONSTITUTION:Look-up tables 11-13 output signals showing whether or not respective chrominance components are object signals of color correction. An AND circuit 14 decides whether or not all of the outputs of the look-up tables 11-13 match one another. Look-up tables 15-17 output color correction quantities corresponding to the chrominance components according to the output of the AND circuit 14. Then adding circuits 18-20 add the color correction quantities to plural chrominance components, component by component. Consequently, only specific colors can be corrected or generated without using a large-capacity memory under three-dimensional control as the look-up tables.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for editing color video signals. In particular, it relates to a device for correcting or coloring a specific color designated in advance without affecting other colors.

[0002]

2. Description of the Related Art Conventionally, in the production of a color video program, the correction of the change in color temperature due to the change of the outdoor, indoor, time, weather, etc., and the color correction or restoration of the color video signal of aged and faded film, etc. Requires a skilled operator to repeatedly operate many correction items such as lightness, saturation, and hue based on the color memory.
In the conventional color correction technology, parameters such as brightness, saturation, and hue are changed for the entire screen of the color video signal to be corrected, so that only a specific color, for example, a facial color is set as the background color. It was difficult to color-correct without affecting.

As one method for solving such a problem, a specific color to be color-corrected is designated, and a correction amount and a coloring amount are calculated in advance for a range of colors centered on the color. Then, a method is considered in which it is stored as a lookup table and then referred to at the time of color correction. This method requires no skill and can correct or color only a specific range of colors without affecting other colors. Further, the correction amount and the coloring amount can be easily and freely controlled only by correcting the table, and the non-linear correction, which is difficult to be realized mainly by the correction using the linear operation, is also very effective.

When correcting or coloring a specific range of colors using a look-up table, it is not sufficient to provide a look-up table independently for a plurality of signals representing colors. For example, a color video signal is represented by three signals of R, G and B, where R = 50, G = 20 and B = 1.
Suppose it was 0. At this time, if an independent table is used for each signal, colors having the same value in any one of the signals, for example, the color of the background wall represented by R = 50, G = 50, and B = 50 are also affected. I will receive it. Therefore, instead of controlling R, G, and B one-dimensionally individually, three-dimensional control is performed,
The correction amount or the coloring amount may be determined for each signal by referring to other input signals. For example, in order to determine the correction amount R ′ of R, not only R but also the input signal values of G and B are referred to.

[0005]

However, if the signal representing the color is directly input to the look-up table, 3
A large memory capacity is required to perform dimension control.
For example, if three signals of R, G, and B are used as color video signals and each signal is quantized with 8 bits, a memory of 3 × 8 bits input and 8 bits output is required for each signal. . Therefore, a memory capacity of 16 Mbytes for each of R, G, and B, for a total of 48 Mbytes, is required.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a color correction device capable of performing color correction accurately and highly accurately with a small memory capacity and with a high degree of freedom.

[0007]

The color correction apparatus of the present invention comprises:
For each of the plurality of color signals, it is determined whether or not all the outputs of the flag means and a flag means that outputs a signal indicating whether or not the color signal is a color correction target signal Determination means, a correction amount output means for outputting a color correction amount for each of a plurality of color signals in accordance with the output of the determination means, and an addition means for adding the color correction amount to the color signal for each color component. It is characterized by that.

Here, the "color signal" may be a signal representing a color as an image, and may be a signal representing a color directly or a signal representing a color indirectly. Thus, for example, R,
It is possible to use a signal that represents the three primary colors such as G and B, or a signal that includes a luminance signal and a color difference signal.

The flag means includes a first storage means for outputting the stored contents by being addressed by the color signal, and the correction amount output means is for outputting the stored contents by being addressed by the output of the judging means. It is desirable to include storage means. These storage means are known as look-up tables. The first storage means stores different values for a plurality of predesignated colors, and the determination means determines when the output values of the first storage means for each of the plurality of color signals are all the same. It is preferable that the configuration is such that a value is output.

The first storage means can be configured to output the same value for a color area centered on a color designated in advance. Specifically, the same value may be stored corresponding to the color area, or the address may be designated only by the upper bits of the color signal.

Regarding a region in which color regions centered on respective colors overlap a plurality of colors designated in advance,
A unit for controlling the ratio of the color correction amount output by the correction amount output unit can be provided. As such means, a central value output means for outputting the central value of the color represented by the output value of the judging means for each color component, and an output value of the central value output means for subtracting the output value for each color component from a plurality of color signals Means, a color correction rate output means for outputting a color correction rate for the color component to the output for each color component of the subtracting means, and an output for each color component of the color correction rate output means are multiplied together. It is preferable to include first multiplication means for outputting the color correction rate and second multiplication means for multiplying the output of the multiplication means by the output of the correction amount output means for each color component.

[0012] The flag means may be configured to output a signal for excluding a color correction target for an area where a color area centered on each color overlaps a plurality of colors designated in advance.

In the above configuration, the flag means outputs a signal (flag) indicating whether or not the color signal is a signal to be color-corrected for each color component. In order to avoid unnaturalness due to color correction when the color regions of colors overlap in all color components, a flag may be output for each combination of two color signals. In this case, the ratio of the color correction amount output by the correction amount output means may be controlled, but it may be set in advance in the flag means. That is, when the look-up table is used as the flag means and the color areas overlap in all the color components, the color areas centering on a plurality of predesignated colors are overlapped by the three or more color signals. The color correction numbers are repeatedly written in the order of the color correction numbers while the correction width is narrowed.

[0014]

The color correction apparatus of the present invention determines whether or not a signal for each color component of a color video signal, for example, each of R, G, and B signals, is to be subjected to color correction, and all color components are to be corrected. At some time, color correction is performed for each color component. Simply, it is performed when the signal of each color component matches a predetermined value. That is, only a specific color designated in advance is color-corrected.

It is also possible to correct a plurality of colors. For that purpose, a flag having a different value for each color is used, and the flag is output for each color component when the color component is a correction target. This can be easily accomplished with a look-up table. That is, a signal for each color component is used as an address input, and a different flag value (color correction number) is read corresponding to the signal value. The same value flag is output for each color component for one color specified in advance, and when the same value flag is read for each color component, color correction is performed according to the flag value. .

Not only a specific color, but also a color region centered on that color can be a correction target. For that purpose, the same flag value is stored not only for the color signal representing the specified color but also for the address input of the values before and after it in the look-up table for determining whether or not it is the correction target. Keep it. Also, the lower bits of the color signal may be truncated.

In the case of correcting a color area centered on a color designated in advance, the boundary may be visually conspicuous if uniform color correction is performed on the color area. In that case, the signal level corresponding to the designated color is set as the center level, and the degree of color correction is changed according to, for example, a normal distribution curve according to the difference between the center level and the level of the original signal. This can be easily accomplished by using a look-up table.

When the color areas overlap, the areas can be excluded. Further, it is also possible to combine the signals for each of the two color components and judge for each combination instead of determining whether or not the correction target is based on the signal for each color component.

[0019]

1 is a block diagram showing a color correction apparatus according to a first embodiment of the present invention. Here, the color video signal is R
A case of expressing with three color signals of (red), G (green), and B (blue) will be described.

The apparatus of this embodiment receives a plurality of color signals respectively representing a plurality of color components, that is, a color video signal including R, G, and B signals, and inputs a color specified in advance in the color video signal. Is a color correction device that outputs a signal that represents a color different from that of the signal that represents, and determines whether or not the color signal is a target of color correction for each of the plurality of color signals. The look-up tables 11 to 13 are provided as flag means for outputting a signal indicating the logical product circuit 1 as a judging means for judging whether or not all outputs of the look-up tables 11 to 13 match.
4, lookup tables 15 to 17 are provided as correction amount output means for outputting color correction amounts for each of a plurality of color signals in accordance with the output of the AND circuit 14, and the color correction amounts are calculated for each color component. It is characterized in that addition circuits 18 to 20 are provided as addition means for adding to a plurality of color signals. Further, a lookup table control microprocessor 10 is provided for writing data in the lookup tables 11 to 13 in advance.

The look-up tables 11-13 are
A correction flag, which is provided separately for each of the R, G, and B signals and which indicates whether color correction is performed or not, is written in an address corresponding to each signal level that represents a predetermined correction or a color to be colored. . For example, R = 50, G =
If you want to correct the complexion represented by 20, B = 10,
By the look-up table control microprocessor 10, correction flag data “1” indicating that color correction is present is previously set at the address 50 of the look-up table 11, the address 20 of the look-up table 12, and the address 10 of the look-up table 13. The correction flag data “0” indicating no color correction is written in advance in the other addresses.

The AND circuit 14 outputs the output signals of the look-up tables 11 to 13 for one-dimensional control, that is, R,
The logical product of the correction flag data indicating the presence or absence of color correction of the three signals of G and B is calculated. This allows, for example, R
= 50, G = 20, B = 10 can be detected, and the color can be designated to be corrected.

The look-up tables 15 to 17 store in advance the color correction amounts of R, G, and B for the designated color, respectively, and according to the output of the AND circuit 14, the color correction amounts for the colors are stored. Output. That is, the look-up tables 15 to 17 output the color correction amount for the designated color when the output of the logical product circuit 14 is "1" and do not perform color correction when the output of the logical product circuit 14 is "0". Therefore, the color correction amount “0” is output.

The adder circuits 18 to 20 add the respective R, G, and B color correction amounts to the respective original signals to obtain color correction outputs.

As described above, in this embodiment, only a specified specific color can be corrected or colored without using a large-capacity memory for three-dimensional control as a lookup table.

FIG. 2 is a block diagram showing a color correction apparatus according to the second embodiment of the present invention. In the apparatus of this embodiment, instead of the look-up tables 11 to 13 in the first embodiment, look-up tables 21 to 23 in which different values are stored for a plurality of colors designated in advance are stored.
Instead of the AND circuit 14, the coincidence detection circuit 24 that outputs the output values of the lookup tables 21 to 23 for each of the plurality of color signals is used, and the color correction amount In order to output 1-bit input look-up tables 15-17, plural-bit input look-up tables 25-27 are used. Lookup tables 21-23 and 25
The stored data of 27 to 27 are preset by the look-up table control microprocessor 10.

In the first embodiment, since the color detection signal (output of the logical product circuit 14) indicating the presence or absence of color correction is 1-bit data, a plurality of color correction designations such as a face color and a clothing color are performed. Requires an equivalent circuit for each color. Therefore, in the second embodiment, as the color detection signal,
As the correction flag data, a plurality of bits of data are used instead of one bit of data. This is hereinafter referred to as "color correction number".

The lookup tables 21-23 include:
The color correction number “1” is assigned to the address of each signal level corresponding to the correction of the complexion, and the color correction number “2” is assigned to the address of the signal level corresponding to the color correction of the clothes. Corresponding to the signal, the color correction numbers are written in the designated order at the addresses corresponding to the respective signal levels representing the designated color.
A specific color correction number is written in advance as an initial value in all addresses other than the correction designation.

The match detection circuit 24 compares the color correction number outputs from the look-up tables 21 to 23 indicating the presence or absence of color correction to detect a match. As a result, only the facial color and the clothing color can be detected separately, and the color correction can be designated.

The look-up tables 25 to 27 use the color correction numbers representing the predesignated colors output from the coincidence detection circuit 24, and the individual color correction amounts of R, G and B corresponding to the color correction numbers. Is output. This allows
When the complexion color is detected, the color correction amount for the complexion color is output, and when the complexion color is detected, the color correction amount for the complexion color is output.

Similar to the first embodiment, the adder circuits 18 to 20 add the respective R, G, and B color correction amounts to the original signal to obtain color correction outputs.

As described above, in the second embodiment, it is not necessary to use a large-capacity memory for the lookup table by the three-dimensional control, and the capacity is slightly increased and the memory control is simple as compared with the first embodiment. This enables correction and coloring of only a plurality of colors designated in advance.

3 and 4 show an example of the stored contents of the look-up table for color correction flag data. Figure 3
Shows the stored contents of the lookup tables 11 to 13 of the first embodiment, and FIG. 4 shows the stored contents of the lookup tables 11 to 13 of the second embodiment. In the first embodiment, each address stores "1" indicating that there is correction or "0" that indicates no correction, whereas in the second embodiment, each address corresponding to the correction of the facial color is stored. The color correction number “1” is stored in the address of the signal level, the color correction number “2” is stored in the address of the signal level corresponding to the color correction of the clothes, and the initial value “FF” is stored in the other areas.

In the above embodiment, the case where the color is designated by only one level has been described. However, in the actual color video signal, even for a facial color, the color signal level has a certain degree of distribution. In the first embodiment, the face color is specified only at one level, and the entire face color cannot be specified. On the other hand, if a color correction number is used as in the second embodiment, a plurality of colors can be designated. However, it is not realistic to identify and specify a subtly different color distribution of the complexion color only by designating each point. Therefore, it is preferable to provide a certain color correction level width corresponding to the distribution of the actual color signal level, rather than the color correction based on the level of one point. That is, the width of the color detection signal with or without color correction is expanded.

For example, when a complexion color represented by R = 50, G = 20, B = 10 is designated, each designated signal level is set as a central level, and, for example, a color correction level width is 8 Then, R = 46 to 54, G = 16
˜24, B = 6 to 14 can be regarded as the distribution of the color signal level of the designated face color.
In such a case, the lookup tables 11-1
3 or 21 to 23, the color correction number is not written only in the address corresponding to the specified color level, but the specified color level is set as the central level and is defined for a certain color correction level width. The color correction number is written in all areas of the address corresponding to the level area. By doing so, all the color signal levels included in the defined facial color distribution (width) are detected, and the corresponding color correction number is output. The processing for this output is as described above. As a result, it becomes possible to easily perform color correction for the entire face color by specifying a single point color correction for the face color correction. FIG. 5 shows an example in which “1” is written with the color correction level width = 8 for the facial color represented by R = 50, G = 20, and B = 10.

Further, the lookup tables 11 to 13 or 2 are provided in order to give a color correction level width to the color to be corrected and to easily perform the color correction by specifying the color correction of one point.
As the input signal to 1 to 23, a signal in which the lower bits of the color signal are truncated may be used. By truncating the lower bits of the input signal of the look-up table, the required memory capacity can be reduced.

FIG. 6 is a block diagram showing a color correction apparatus according to the third embodiment of the present invention. In this embodiment, the ratio of the color correction amounts output from the correction amount output look-up tables 25 to 27 for the regions in which the color regions centered on the respective colors overlap a plurality of predesignated colors. It is different from the second embodiment in that it is provided with a means for controlling. That is, the lookup tables 31 to 33 are provided as central value output means for outputting the central value of the color represented by the output value of the coincidence detection circuit 24 for each color component, and the output values of the lookup tables 31 to 33 are R. , G, B signals are provided with subtraction circuits 34 to 36 as means for subtracting each color component, and a color correction for outputting a color correction rate for each color component to the output of each color component of the subtraction circuits 34 to 36. Lookup tables 37 to 39 are provided as rate output means,
A multiplication circuit 40 is provided as a first multiplication means for multiplying the output for each color component of the look-up tables 37 to 39 to output the total color correction rate, and the output of the multiplication circuit 40 is looked up for correction amount output.・ Tables 25-27
The multiplication circuits 41 to 43 are provided as the second multiplication means for multiplying the output of each of the color components by color components. Lookup table 2
1-23, 25-27, 31-33, and 37-39
Stored data is preset by the look-up table control microprocessor 10.

When the color correction number is switched on and off by the color correction number as in the second embodiment, the boundary between the color correction and the color correction becomes noticeable visually. Therefore, the central levels of the designated signal levels of R, G, and B are stored in the lookup tables 31 to 33 in association with the color correction numbers. When the center levels output from the lookup tables 31 to 33 corresponding to the color correction numbers are subtracted from the original signals by the subtraction circuits 34 to 36, the difference from the center level is obtained. A color correction ratio value corresponding to the difference value is stored in advance in the look-up table, and the ratio value as a color correction ratio is output based on the output values of the subtraction circuits 34 to 36.

Lookup table 37 for color correction factors
.About.39 output "1.0" as the color correction rate when the input is "0", that is, when the input color video signal is equal to the color signal level designated for color correction. Further, when the absolute value of the input is “color correction level width / 2” or more, it can be considered that there is no color correction, so “0.0” is output as the color correction rate. When the input is between "0" and "color correction level width / 2", an intermediate value is output. As the change rate, for example, a normal distribution curve may be used.

The multiplication circuit 40 multiplies each output in order to perform three-dimensional control by the outputs of the look-up tables 37 to 39, and the obtained ratio value is used as a total color correction factor, R,
It is used for switching control with or without color correction of G and B respectively.

The outputs of the multiplication circuit 40 are multiplied by the multiplication circuits 41 to 41.
The output of the look-up tables 25-27 is multiplied by 43, and added to the original signal by the adder circuits 18-20.
As a result, the color correction rate output of the multiplication circuit 40 is "1.0".
, The color correction outputs output from the lookup tables 25 to 27 are added to the original signal as the final color correction amount. When the color correction rate output of the multiplication circuit 40 is “0.0”, the original signal is output as it is. To be done. In addition, the multiplication circuit 40
If the color correction rate output of is an intermediate value, it is multiplied by the outputs of the look-up tables 25 to 27 and added to the original signal to form the color correction output. In this way, it is possible to perform correction such that the corrected color boundary becomes natural in terms of visual evaluation.

As described above, by introducing the color correction number, the color correction level width and the color correction rate, it becomes possible to correct or color a plurality of colors with a simple color correction designation.

However, when a similar color is designated for color correction, the writing addresses of the color correction numbers in the lookup tables 21 to 23 for writing the color correction numbers are duplicated depending on how the color correction levels are set. It may happen. Such an example is shown in FIG. In the example of this figure, two colors represented by the color correction numbers “1” and “2” are designated, and the G color components of these two colors overlap.

In such a case, as shown in FIG.
In the overlapping writing address, a specific color correction number,
In this example, "0" is written as the overlap detection color correction number. When “0” exists in the color correction number of any of the three signals of R, G, and B, comparison and coincidence detection are performed using the other color correction numbers, and adopted as the final color correction number. .

FIG. 9 is a block diagram showing a fourth color correction apparatus of the present invention. In this embodiment, the look-up tables 51 to 53 each of which inputs a combination of two color signals as flag means for outputting a signal indicating whether or not the input color signal is a color correction target signal. Is different from the third embodiment. Lookup tables 25-27, 31-33, 37-39, and 51-
The stored data of 53 is preset by the look-up table control microprocessor 10.

FIG. 10 shows an example of overlapping of color signals. In this example, for the two color correction designation points represented by the color correction numbers “1” and “2”, “1” and “2” overlap with each other for the R signal and “1” for the G signal, “3” overlaps each other, and for the B signal, “2” and “3” overlap each other. Thus, when there is an address corresponding to the overlapping color correction number in all three signals of R, G, and B for any two arbitrary color correction designation points, or when a plurality of color correction designations are made, When it is impossible to distinguish between the addresses corresponding to a plurality of overlapping correction addresses that occur, it is not possible to deal with the method of writing the overlap detection color correction number in the overlapping writing addresses.

Therefore, in the embodiment shown in FIG. 9, the lookup table for generating the color correction number is not a lookup table for one-dimensional control, but a lookup for two-dimensional control in which two signals of R and G are input. A table 51, a two-dimensional control lookup table 52 that receives two signals G and B, and a two-dimensional control lookup table 53 that receives two signals G and R are used. Thereby, the overlapping area of the color signals can be avoided.

As a method of avoiding this overlapping area, a method of giving priority to subsequent designation is simply used. That is, when an overlapping region occurs in all three R, G, and B signals with respect to two arbitrary designated correction points, the color correction number for the color correction point designated later is overwritten as it is. FIG. 11 shows an example of the color boundary by overwriting when the normal distribution curve is used as a function of the correction factor change.

However, in such a simple method, as shown in FIG.
As shown in FIG. 1, the change rate sharply changes at the overlapping boundary, and the color correction output becomes visually noticeable.
In some cases, the center level specified for color correction does not reach the specified color signal level.

Therefore, when an overlapping region occurs in all three signals of R, G, and B, when the color correction number is written, first, a predetermined color correction level width is used, and the post designation priority is given. Each lookup by correction number in order
Write the correction number in the table. After that, while the color correction level width is gradually narrowed, the color correction numbers are repeatedly written in the order of the correction numbers with the post designation priority. Figure 1 shows the flow of this operation.
2 shows.

This operation will be further described with reference to FIGS. 13 to 19.

If there are overlapping areas in the color correction numbers "1" and "2" in the one-dimensional color signal space as shown in FIG. 13, the overlapping areas are divided into areas as shown in FIG. It is desirable to divide. To do so, simply divide at the intersection.

Next, the case of the two-dimensional color signal space will be described. Also in this case, it is assumed that there are overlapping areas with color correction numbers “1” and “2” as shown in FIG. At this time, if the one-dimensional intersection division is applied, the correction designation area decreases as shown by the diagonal lines in FIG. 16 when viewed in a two-dimensional space. Ideally, as shown in FIG. 17, it is desired to divide the overlapping areas into one another. Therefore, as described above, the color correction number is repeatedly written while the color correction level width is gradually narrowed. In this way, the boundaries of the two approaches the dividing line shown in FIG. 17 little by little. This is shown in FIG.

In FIG. 18, a thick line shows a newly written area and a thin line shows an already written area. In this example, the color correction number "1" is written first, and then the color correction number "2" is written. Next, the color correction level width is narrowed, and the color correction number "1" is written again, and then the color correction number "2" is written. The same data is repeatedly written in the portions other than the boundary, but the write control is simpler in that case. In this way, the area is divided as shown in FIG.

In this way, for the correction center level, only the correction lower limit obtained from the color correction level width = correction center level−color correction level width / 2, correction upper limit = correction center level + color correction level width / 2 Using the data, the optimum area division can be obtained only by a simple repetitive writing device without performing complicated arithmetic processing.

FIG. 19 shows an example of the correction distribution curve in the color space obtained by the optimum division of the correction area. Here, a normal distribution curve was used as the correction factor function.

That is, by performing such a simple repetitive operation, R, G, and
Even if an overlapping area occurs in all three B signals, the optimum color correction area division can be performed, and a color correction output that is natural in terms of visual evaluation can be obtained.

Such a repetitive operation can be used even in the case of one dimension, and the same result as the simple intersection division can be obtained. In addition, the optimum division is similarly obtained when it is used in three dimensions.

In the above description, the case where the quantized R, G, B signals are used as the color signals has been described, but the present invention can be similarly implemented by using the digital color converted analog color video signals. The present invention can be similarly implemented by using signals other than the RGB signals, for example, the luminance signal and the color difference signal YCbCr.

When the luminance signal and the color difference signal YCbCr are used, the brightness and color are corrected so that they match the brightness and color level distribution characteristics of the actual color video signal. In that case, the function form of the color correction level width and the change of the color correction rate can be set independently for the luminance signal and the color difference signal, and the contents of the lookup tables can be rewritten easily. The function form of the color correction level width and the change of the color correction rate is set broadly and gently for the luminance signal representing the brightness, and the color correction level width and the change of the color correction rate are set for the color difference signal representing the color. It is good to select the function form relatively narrowly and sharply.
It is also possible to correct only the color component using only the color difference signal, or to correct the color difference signal using the luminance signal, and conversely, to correct the luminance signal using the color difference signal.

[0061]

As described above, the color correction apparatus of the present invention uses a plurality of look-up tables having a small memory capacity, so that the color of the input color video signal can be accurately and highly accurately and with a high degree of freedom. Can be corrected or colored. In addition, the smaller look-up table capacity reduces the amount of color correction data written to the table, so it is possible to change the data in a short time. It is also possible to change the correction amount.

The present invention has a great effect when it is used for editing and producing a television or other video program, and for restoring a film that has deteriorated and is discolored.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a color correction apparatus according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an example of stored contents of a look-up table for color correction flag data in the first embodiment.

FIG. 4 is a diagram showing an example of stored contents of a lookup table for color correction flag data in the second embodiment.

FIG. 5 is a diagram showing an example in which the same color correction number is written in a plurality of addresses corresponding to the color correction level width.

FIG. 6 is a block configuration diagram showing a color correction apparatus of a third embodiment of the present invention.

FIG. 7 is a diagram showing an example in which write addresses of color correction numbers are duplicated in a lookup table for writing color correction numbers.

FIG. 8 is a diagram showing an example in which an overlap detection color correction number is written in overlapping writing addresses when color signals of two colors overlap.

FIG. 9 is a block configuration diagram showing a fourth color correction device of the present invention.

FIG. 10 is a diagram showing an example of overlapping of color signals.

FIG. 11 is a diagram showing an example of color boundaries by overwriting when a normal distribution curve is used as a function of a correction factor change.

FIG. 12 is a diagram showing a flow of an operation of a color correction level width when an overlapping area occurs in all three signals of R, G and B.

FIG. 13 is a diagram showing a state in which a color correction number has an overlapping area in a one-dimensional signal space.

FIG. 14 is a diagram showing optimum area division in the case of one dimension.

FIG. 15 is a diagram showing a state where an overlapping area exists in a color correction number in a two-dimensional signal space.

FIG. 16 is a diagram showing a region of each color correction number when intersection division is performed in a two-dimensional signal space.

FIG. 17 is a diagram showing ideal area division.

FIG. 18 is a diagram showing how the boundary between two color correction number areas gradually approaches an ideal dividing line.

FIG. 19 is a diagram showing an example of a correction distribution curve in a color space obtained by optimal division of a correction area.

[Explanation of symbols]

10 Look-up table control microprocessor 11-13, 15-17, 21-23, 25-27, 3
1-33, 37-39, 51-53 Look-up table 14 AND circuit 18-20 Adder circuit 24 Match detection circuit 34-36 Subtractor circuit 40-43 Multiplier circuit

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Claims (9)

[Claims] 1. A color video signal including a plurality of color signals respectively representing a plurality of color components is input and a color different from the color representing a predetermined color contained in the color video signal is input. A color correction device that outputs a signal that represents the flag means (11 to 13, 21) that outputs a signal that indicates whether or not the color signal is a signal to be subjected to color correction for each of the plurality of color signals. 23 to 23), a judging means (14, 24) for judging whether or not the outputs of the flag means are all in agreement, and a color correction amount for each of the plurality of color signals is output in accordance with the output of the judging means. Correction amount output means (1
5-17, 25-27), and addition means (18-20, 28-30) for adding the color correction amount to the plurality of color signals for each color component. apparatus. 2. The flag means includes first storage means which is addressed by the color signal and outputs its stored contents, and the correction amount output means is addressed by the output of the judgment means and its stored contents. The color correction device according to claim 1, further comprising a second storage unit that outputs 3. The first storage means (21-23) stores different values for a plurality of colors designated in advance, and the determination means stores the first value for each of the plurality of color signals. 3. The color correction device according to claim 2, wherein when the output values of the storage means are all the same, the value is output. 4. The color correction apparatus according to claim 2, wherein the first storage unit is configured to output the same value for a color area centered on a color designated in advance. 5. A means (31-43) for controlling the ratio of the color correction amount output by the correction amount output means for a region in which a color region centered on each color overlaps a plurality of colors designated in advance. 5. The color correction device according to claim 1, further comprising: 6. The means for controlling the ratio of the color correction amount includes center value output means (31 to 33) for outputting the center value of the color represented by the output value of the determination means for each color component, and the center value output means (31 to 33). A means (34 to 36) for subtracting the output value of the value output means from the plurality of color signals for each color component, and a color correction rate for the color component with respect to the output for each color component of the subtracting means. Color correction rate output means (37
To 39), a first multiplication means (40) for multiplying the output of each color component of the color correction rate output means to output a total color correction rate, and an output of the multiplication means for the correction amount output means (25). ~ 2
The color correction device according to claim 5, further comprising second multiplication means (41 to 43) for multiplying the output of 7) for each color component. 7. The flag means is configured to output a signal not to be subjected to color correction for a region in which a color region centered on each color overlaps a plurality of colors designated in advance. The color correction device according to claim 1. 8. A color video signal including three or more color signals respectively representing three or more color components is input, and a signal representing a prespecified color included in the color video signal is different from the color. In a color correction device that outputs a signal representing a color, for each of the combinations of two color signals of the above three or more color signals, whether or not the combined color signal is a signal to be subjected to color correction. Flag means (51 to 53) for outputting a signal indicating that, a judging means (24) for judging whether or not all the outputs of the flag means match, and the plurality of colors according to the output of the judging means. Correction amount output means (2) for outputting the color correction amount for each of the signals
5 to 27), addition means (28 to 30) for adding the output of the correction amount output means to the plurality of color signals for each color component, and each color for a plurality of predesignated colors. A means (31) for controlling the ratio of the color correction amount output by the correction amount output means for the area where the central color area overlaps.
To 43) are included. 9. A color video signal including three or more color signals respectively representing three or more color components is input, and a signal representing a prespecified color included in the color video signal is different from the color. A color correction device for outputting a signal representing a color, which is provided for each combination of two color signals of the three or more color signals, is addressed by the combined color signal, and outputs its stored contents. The storage means (51-53) for performing the determination and the determination means (2) for determining whether or not the outputs of the storage means are the same for each of the combinations.
4) and a correction amount output means (2) for outputting a color correction amount for each of the plurality of color signals according to the output of the determination means.
5 to 27), addition means (28 to 30) for adding the output of the correction amount output means to the plurality of color signals for each color component, and representing the color when the color to be corrected is designated. A means (10) for writing a color correction number to a corresponding address of the storage means is provided, wherein the writing means is an area in which color areas centering on a plurality of colors designated in advance overlap with the three or more color signals. Regarding the above, the color correction apparatus further comprises means for repeatedly writing the color correction numbers in the order of the color correction numbers while narrowing the correction width sequentially.