JP3344016B2 - Video signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing device for a color video camera.

[0002]

2. Description of the Related Art FIG. 23 is a block circuit diagram showing a conventional video signal processing device. In the figure, 24, 25, 26
Is a gain control circuit.

Next, the operation will be described. The gain control circuits 24 and 25 control the gain of the RY color difference signal and the BY color difference signal by the control signals KR and KB in order to perform appropriate color reproduction. The gain control circuit 26 controls the gain of the luminance signal Y in accordance with the control signal KY.

[0004]

Since the conventional video signal processing apparatus is configured as described above, the hue is RY
There is a problem that only the gains of the axis and the BY axis can be changed, and correction of a specific color affects other colors.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a simple circuit configuration in which a good image in which only a color region to be detected is color-corrected by a natural change without affecting other colors can be used. It is an object of the present invention to obtain a video signal processing device realized by the above.

[0006]

According to a first aspect of the present invention, there is provided a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. Is output within the hue range, the saturation determined from the first color difference signal and the second color difference signal, and the difference between the hue determined from the first color difference signal and the second color difference signal and the representative value of the hue range of the specific color are output. A look-up table that outputs a value that can be distinguished from the output value outside the hue range of the specific color is provided. By inputting the first color difference signal and the second color difference signal to the look-up table, it is determined whether or not the hue range and saturation ranges, if the color of the hue range and saturation range of the specific color, and outputs a detection signal indicating a specific color region, the saturation degree of the specific color Compare with the representative value of the saturation range and When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the saturation and the difference between the representative value of the hue range of the specific color is subtracted. When the saturation is smaller than the representative value of the saturation range of the specific color, the difference between the saturation and the lower limit of the saturation range of the specific color is used to calculate the difference between the representative value of the hue range of the specific color. It outputs the reduced one.

A video signal processing device according to a second aspect of the present invention is a video signal processing device for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether the color is within the range, and if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output ,
Comparing the saturation with a representative value of the saturation range of the specific color,
When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the saturation is subtracted from the difference between the representative value of the hue range of the specific color. Is sliced, and when the saturation is smaller than the representative value of the saturation range of the specific color, the representative value of the hue range of the specific color is obtained from the difference between the saturation and the lower limit of the saturation range of the specific color. Is obtained by slicing the difference obtained by subtracting the difference.

A video signal processing apparatus according to a third aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether the color is within the range, and if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output ,
Comparing the saturation with a representative value of the saturation range of the specific color,
When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the saturation is subtracted from the difference between the representative value of the hue range of the specific color. When the saturation is smaller than the representative value of the saturation range of the specific color, the representative value of the hue range of the specific color is calculated from the difference between the saturation and the lower limit of the saturation range of the specific color. Non-linear conversion of the difference between the value and the difference is output.

A video signal processing apparatus according to a fourth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether the color is within the range, and if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output ,
Comparing the saturation with a representative value of the saturation range of the specific color,
When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the representative value of the hue range of the specific color is subtracted from the difference between the upper limit of the saturation range of the specific color and the saturation. Is passed through a low-pass filter or a band-pass filter, and when the saturation is smaller than the representative value of the saturation range of the specific color, the specific color Is output after passing through a low-pass filter or a band-pass filter after subtracting the difference from the representative value of the hue range.

A video signal processing apparatus according to a fifth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition and subtraction of the second color difference signal to and from the first color difference signal; a first color difference signal and a second color difference signal within a hue range of a specific color. And the difference between the hue determined from the first color difference signal and the second color difference signal and the representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color And a first color difference signal And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. By determining whether the color is within the saturation range of the specific color, if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output , Compare the representative value of the saturation range of the color, and if the saturation is greater than the representative value of the saturation range of the specific color, determine the specific color from the difference between the upper limit of the saturation range of the specific color and the saturation. A value obtained by subtracting the difference from the representative value of the hue range is output as a correction amount. If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the lower limit of the saturation range of the specific color are output. Corrected by subtracting the difference from the representative value of the hue range of the specific color from the difference from the value Output as the first gain control means and the second gain control means and controlled independently in accordance with the magnitude of the correction amount, and performs color correction of the specific color area.

A video signal processing apparatus according to a sixth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition and subtraction of the second color difference signal to and from the first color difference signal; a first color difference signal and a second color difference signal within a hue range of a specific color. And the difference between the hue determined from the first color difference signal and the second color difference signal and the representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color And a first color difference signal And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. By determining whether the color is within the saturation range of the specific color, if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output , Compare the representative value of the saturation range of the color, and if the saturation is greater than the representative value of the saturation range of the specific color, determine the specific color from the difference between the upper limit of the saturation range of the specific color and the saturation. A value obtained by subtracting the difference from the representative value of the hue range is output as a correction amount. If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the lower limit of the saturation range of the specific color are output. Corrected by subtracting the difference from the representative value of the hue range of the specific color from the difference from the value And outputs as the first in accordance with the magnitude of the output obtained by slicing the correction amount
The gain control means and the second gain control means are independently controlled to perform color correction of a specific color area.

A video signal processing apparatus according to a seventh aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition and subtraction of the second color difference signal to and from the first color difference signal; a first color difference signal and a second color difference signal within a hue range of a specific color. And the difference between the hue determined from the first color difference signal and the second color difference signal and the representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color And a first color difference signal And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. By determining whether the color is within the saturation range of the specific color, if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output , Compare the representative value of the saturation range of the color, and if the saturation is greater than the representative value of the saturation range of the specific color, determine the specific color from the difference between the upper limit of the saturation range of the specific color and the saturation. A value obtained by subtracting the difference from the representative value of the hue range is output as a correction amount. If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the lower limit of the saturation range of the specific color are output. Corrected by subtracting the difference from the representative value of the hue range of the specific color from the difference from the value Output as, the correction amount of the first gain control means and the second gain control means and controlled independently in accordance with the magnitude of the output obtained by non-linear transformation, and performs color correction of the specific color area.

According to an eighth aspect of the present invention, there is provided a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition and subtraction of the second color difference signal to and from the first color difference signal; a first color difference signal and a second color difference signal within a hue range of a specific color. And the difference between the hue determined from the first color difference signal and the second color difference signal and the representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color And a first color difference signal And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. By determining whether the color is within the saturation range of the specific color, if the color is within the hue range of the specific color and within the saturation range, a detection signal indicating the specific color area is output , Compare the representative value of the saturation range of the color, and if the saturation is greater than the representative value of the saturation range of the specific color, determine the specific color from the difference between the upper limit of the saturation range of the specific color and the saturation. A value obtained by subtracting the difference from the representative value of the hue range is output as a correction amount. If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the lower limit of the saturation range of the specific color are output. Corrected by subtracting the difference from the representative value of the hue range of the specific color from the difference from the value The first gain control means and the second gain control means are independently controlled in accordance with the magnitude of the output obtained by passing the correction amount through a low-pass filter or a band-pass filter to perform color correction of a specific color area. It is what you do.

According to a ninth aspect of the present invention, the contents of the look-up table provided in the video signal processing apparatus of the first to eighth aspects are the first color difference signal and the second color difference signal.
, The difference between the hue determined from the first and second color difference signals and the representative value of the hue range of the specific color, and whether the color is within the hue range of the specific color or outside the hue range. If the first color difference signal and the second color difference signal are within the hue range of the specific color, the upper n of the first color difference signal of m bits and the second color difference signal of m bits enter the bits in the look-up table, respectively, those of the saturation portion of the output was increased by m-n bits to a first saturation, the lower m-n of the first color difference signal
The first color difference signal and the second color difference signal are obtained by adding the saturation portion of the output obtained by inputting the bits and the lower mn bits of the second color difference signal to the look-up table to the first saturation. The saturation degree is determined from the color difference signal.

According to a tenth aspect of the present invention, the contents of the look-up table provided in the video signal processing apparatus of the first to eighth aspects are the first color difference signal and the second color difference signal.
, The difference between the hue determined from the first and second color difference signals and the representative value of the hue range of the specific color, and whether the color is within the hue range of the specific color or outside the hue range. hue range identification flag der to is, the higher the first color difference signal and the second case is the color difference signal is within the hue range of the specific color, the first color difference signal and second color difference signals of the m bits of the m bits and n bits is inputted to the look-up table, respectively, those of the saturation portion of the output was increased by m-n bits to a first saturation, the lower m-n of the first color difference signal
The bit amount and the lower mn bits of the second color difference signal are compared with each other by a comparator, and the larger one is added to the first saturation degree, and the sum calculated as the saturation degree determined from the first and second color difference signals. Is what you do.

[0016]

According to a first aspect of the present invention, there is provided a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal, and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether it is within the range. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output.
Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. A value obtained by subtracting the difference between the representative value of the specific color hue range and the representative value of the specific color from the difference is output.If the saturation is smaller than the representative value of the specific color saturation range, the saturation and the specific color saturation are output. Since a value obtained by subtracting the difference from the representative value of the hue range of the specific color from the difference from the lower limit of the degree range is output, there is an effect that the degree of approximation of the specific color can be quantitatively detected.

A video signal processing apparatus according to a second aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal, and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether it is within the range. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. The difference between the saturation and the representative value of the hue range of the specific color is subtracted from the difference and the sliced output is obtained.If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the specific Since the difference between the lower limit of the color saturation range and the difference from the representative value of the hue range of the specific color is subtracted and sliced and output, it is possible to quantitatively detect the degree of approximation of the specific color. There is an effect.

A video signal processing apparatus according to a third aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal, and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table, so that the hue range of the specific color and the saturation It is determined whether it is within the range. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. Non-linear conversion of the difference between the representative value of the hue range of the specific color and the difference between the representative value of the hue range of the specific color and output.If the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and Since the difference between the specific color saturation range and the lower limit of the specific color hue range is subtracted from the lower limit value of the specific color and nonlinearly converted and output, the approximation degree of the specific color can be detected as the perceived amount. There is a possible effect.

A video signal processing apparatus according to a fourth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. And outputting a difference between a saturation determined from the first color difference signal and the second color difference signal and a difference between a hue determined from the first color difference signal and the second color difference signal and a representative value of a hue range of the specific color. A look-up table that outputs a value that can be distinguished from the output value outside the range; and a first color difference signal and a second color difference signal are input to the look-up table. It is determined whether it is within the range. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. When a difference between the saturation and the representative value of the hue range of the specific color is subtracted from the difference and output through a low-pass filter or a band-pass filter, and the saturation is smaller than the representative value of the saturation range of the specific color. A low-pass filter or a band-pass filter outputs a value obtained by subtracting the difference between the saturation and the representative value of the hue range of the specific color from the difference between the lower limit of the saturation range of the specific color. There is an effect that the similarity can be quantitatively detected.

A video signal processing apparatus according to a fifth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition / subtraction of the second color difference signal to / from the first color difference signal; a first color difference signal and a second color difference signal within a specific color hue range. And a difference between the hue determined from the first color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color. And a first color difference signal. And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. Thus, it is determined whether or not it is within the saturation range of the specific color. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. The difference between the saturation and the representative value of the hue range of the specific color is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the specificity are determined. A value obtained by subtracting the difference from the representative value of the hue range of the specific color from the difference from the lower limit value of the color saturation range is output as a correction amount. (2) Since the two gain control means are independently controlled to perform color correction of a specific color area, it is possible to perform color correction of a specific color with a natural change in which a boundary is not noticeable without affecting other colors. There is an effect.

A video signal processing apparatus according to a sixth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. First arithmetic means for adding / subtracting the first color difference signal to / from the second color difference signal, first gain control means for controlling the amount of addition / subtraction of the first color difference signal to / from the second color difference signal, and addition / subtraction of the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition / subtraction of the second color difference signal to / from the first color difference signal; a first color difference signal and a second color difference signal within a specific color hue range. And a difference between the hue determined from the first color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color. And a first color difference signal. And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. Thus, it is determined whether or not it is within the saturation range of the specific color. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. The difference between the saturation and the representative value of the hue range of the specific color is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the specificity are determined. A value obtained by subtracting the difference between the hue range of the specific color and the representative value of the hue range of the specific color from the difference from the lower limit of the color saturation range is output as a correction amount. Since the control means and the second gain control means are independently controlled to perform the color correction of the specific color area, the color correction of the specific color can be performed with a natural change in which the boundary is less noticeable without affecting other colors. There is an effect that can be performed.

A video signal processing apparatus according to a seventh aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition / subtraction of the second color difference signal to / from the first color difference signal; a first color difference signal and a second color difference signal within a specific color hue range. And a difference between the hue determined from the first color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color. And a first color difference signal And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. Thus, it is determined whether or not it is within the saturation range of the specific color. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. The difference between the saturation and the representative value of the hue range of the specific color is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the specificity are determined. A value obtained by subtracting the difference from the representative value of the hue range of the specific color from the difference from the lower limit of the color saturation range is output as a correction amount, and the first amount is output according to the magnitude of the output obtained by nonlinearly converting the correction amount. In order to independently control the gain control means and the second gain control means and perform color correction of a specific color area,
There is an effect that color correction of a specific color can be performed with a natural change in which boundaries are less noticeable without affecting other colors.

An image signal processing apparatus according to an eighth aspect of the present invention is a video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal. A first calculating means for adding / subtracting the first color difference signal to / from the second color difference signal, a first gain control means for controlling an amount of adding / subtracting the first color difference signal to / from the second color difference signal, and adding / subtracting the second color difference signal to / from the first color difference signal. A second calculating means for controlling the amount of addition / subtraction of the second color difference signal to / from the first color difference signal; a first color difference signal and a second color difference signal within a specific color hue range. And a difference between the hue determined from the first color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and a value that can be distinguished from the output value outside the hue range of the specific color. And a first color difference signal. And the second color difference signal are input to the lookup table to determine whether or not the color is within the hue range of the specific color. If the hue is within the hue range of the specific color, the saturation and the luminance signal are further compared. Thus, it is determined whether or not it is within the saturation range of the specific color. If the color is within the hue range and the saturation range of the specific color, a detection signal indicating the specific color area is output. Further, comparing the saturation with a representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the upper limit of the saturation range of the specific color and the saturation value are compared. The difference between the saturation and the representative value of the hue range of the specific color is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the saturation and the specificity are determined. A value obtained by subtracting the difference from the representative value of the hue range of the specific color from the difference from the lower limit of the color saturation range is output as a correction amount, and the output of the correction amount passed through a low-pass filter or a band-pass filter. Since the first gain control means and the second gain control means are independently controlled in accordance with the above, and color correction of a specific color area is performed, natural changes in which boundaries are less noticeable without affecting other colors. Can perform color correction for specific colors There is that effect.

According to a ninth aspect of the present invention, the contents of the look-up table provided in the video signal processing apparatus of the first to eighth aspects are the first color difference signal and the second color difference signal.
And the difference between the hue determined from the first and second color difference signals and the representative value of the hue range of the specific color, and distinguishing between the hue range of the specific color and the hue range. Hue range identification flag. When the first color difference signal and the second color difference signal are within the hue range of the specific color, the upper n bits of the m-bit first color difference signal and the m-bit second color difference signal are respectively stored in a lookup table. A value obtained by increasing the saturation portion of the input and the output by mn bits is defined as the first saturation. Further, the lower-order mn bits of the first color difference signal and the lower-order mn bits of the second color difference signal are respectively input to the look-up table, and the saturation portion of the output obtained is used as the first saturation. Since the sum is the saturation determined from the first color difference signal and the second color difference signal, there is an effect that the calculation error can be reduced even if the capacity of the look-up table is reduced.

According to a tenth aspect of the present invention, the look-up table provided in the video signal processing apparatus of the first to eighth aspects includes a first color difference signal and a second color difference signal.
And the difference between the hue determined from the first and second color difference signals and the representative value of the hue range of the specific color, and distinguishing between the hue range of the specific color and the hue range. Hue range identification flag. When the first color difference signal and the second color difference signal are within the hue range of the specific color, the upper n bits of the m-bit first color difference signal and the m-bit second color difference signal are respectively stored in a lookup table. A value obtained by increasing the saturation portion of the input and the output by mn bits is defined as the first saturation. Further, the lower mn bits of the first chrominance signal and the lower mn bits of the second chrominance signal are compared by a comparator, and the larger one is added to the first saturation to obtain the first chrominance. Since the saturation is determined by the signal and the second color difference signal, there is an effect that the calculation error can be reduced even if the capacity of the lookup table is reduced.

[0026]

[Embodiment 1] FIG. 1 is a block circuit diagram showing a video signal processing device according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a lookup table, and reference numeral 2 denotes a specific color detection circuit.

Next, the operation will be described. By inputting the RY color difference signal and the BY color difference signal to the look-up table 1, a specific color is determined from the saturation C determined from the first color difference signal and the second color difference signal, and from the saturation C to the saturation C. Is subtracted from the representative value of the hue range by multiplying by the coefficient K, which is a deviation from the representative value of the hue range. The coefficient K has the maximum value at the representative value of the hue range of the specific color, decreases as the distance from the representative value of the hue range of the specific color decreases, and reaches the minimum value at the boundary of the hue range of the specific color. The saturation C is calculated as in the following equation (1). The coefficient K is calculated as in the following equation (2). As shown in FIG. 2, the relationship between θ and φ in equation (2) is θ
Is the angle between the positive direction axis of the BY axis and the representative value of the hue range of the specific color, and φ is the angle between the positive direction axis of the BY axis and the hue of the data to be written in the look-up table 1. . Therefore, if the absolute value of the difference between these two angles increases, K decreases. K1 becomes inoperable when | θ−φ | becomes 0, and is therefore added to the denominator as an appropriate coefficient. The K1 of the numerator is for normalizing K to 1, and as K1 is increased, the effect of | θ−φ | on K becomes weaker. C = ((R−Y) ² + (B−Y) ² )) ^0.5 (1) K = K1 / (K1 + | θ−φ |) (2) As shown in FIG. In the area, the upper 5 bits store the degree of saturation C with respect to the inputs RY and BY, and the lower 3 bits store the difference S. Outside the specific color area, 0 is stored in the lookup table 1. Here, K1 is set to 20, and the units of θ and φ are expressed in degrees, but other units may be used. However, the coefficient K1 needs to be similarly converted if the unit changes. The saturation C and the difference S of the lookup table 1 and the luminance signal Y are input to the specific color detection circuit 2 and the approximation signal A
P and the detection signal D are obtained. The approximation signal AP has a maximum value when it is a representative value of the saturation range of the specific color and a representative value of the hue range of the specific color. The detection signal D is a sign bit of the approximation signal AP, and is 1 when the specific color is negative and 0 when the specific color is positive.

The specific color detection circuit 2 will be described. The specific color detection circuit 2 is configured as shown in FIG. In FIG. 4, 3 is a comparator, 4 is a switch circuit, 5 and 6 are adders,
7 is a zero comparator, 8 is an OR gate, and 9 is an adder.

Next, the operation will be described. In the three-dimensional space represented by the RY color difference signal, the BY color difference signal, and the luminance signal Y, all points distributed on a vector extending in a certain direction from the origin can be said to be the same color. 5 is represented. Here, utilizing the correlation between the color difference signal and the luminance signal, the saturation range of the specific color region is determined by the relationship between the saturation C and the luminance signal Y as shown in the following equation (3). Here, a and b are constants, and aY is the lower limit of the saturation range of the specific color, and bY is the upper limit (a <b) of the saturation range of the specific color. aY ≦ C ≦ bY (3) Here, for example, Y is 26, a is 1/16, and b is １ ／.
Then, the specific color area is a range surrounded by a thin line in FIG.

A color in which the output C of the lookup table 1 exists within the range of the equation (3) is regarded as a color within the saturation range of the specific color. Here, a representative value d of the saturation range of the specific color that satisfies the relationship a <d <b is set. In FIG. 4 , a comparator 3 compares dY and C obtained by multiplying the luminance signal Y by d,
If dY ≦ C, 0 is set as the output of the comparator 3, and if dY> C, 1 is set as the output of the comparator 3. Also, C is calculated by the adder 5.
Then, an output C-aY obtained by subtracting aY from bY and an output bY-C obtained by subtracting C from bY by the adder 6 are input to the switch circuit 4. Here, when the outputs from the adders 5 and 6 are negative values, they are indicated by two's complement. The most significant bit (MSB) of the outputs of the adders 5 and 6 is a sign bit, and is 1 when negative and 0 when positive. In the switch circuit 4, if the output of the comparator 3 is 0, bY-C, and if the output of the comparator 3 is 1, C-a.
Switch to Y and output its value. Further, the adder 9 removes the difference S from the output value to obtain an approximation signal AP that takes into account the deviation of the hue range of the specific color from the representative value.
If the approximation signal AP is positive, it is regarded as a color in the specific color region, and if negative, it is regarded as a color outside the specific color region. Only the sign bit of the approximation signal AP is extracted and input to the OR gate 8. The zero comparator 7 outputs 1 when the saturation C is 0, outputs 0 when the saturation C is not 0, and inputs the output value of the zero comparator 7 to the OR gate 8. Therefore detection signal D hue outside the scope of a specific color at saturation C 0 of the detected color Luke or saturation C, and the formula (3)
When the color to be detected is outside the hue range of the specific color and within the saturation range, the value is set to 1. The approximation signal AP and the detection signal D
6 is shown in FIG. The approximation signal AP has the maximum value of the representative value of the saturation range of the specific color and the representative value of the hue range of the specific color as a maximum, and becomes larger for colors closer to the specific color and smaller for colors shifted from the specific color. The detection signal D is set to 0 only in the specific color area,
It is set to 1 outside the specific color area. As a result, it is possible to quantitatively detect the degree of approximation of a specific color.

Embodiment 2 FIG. FIG. 7 is a block circuit diagram showing a video signal processing device according to Embodiment 2 of the present invention. In the figure, the same parts as those in FIG. Reference numeral 10 denotes a slice circuit.

Next, the operation will be described. By inputting the RY color difference signal and the BY color difference signal to the look-up table 1, a saturation C and a difference S determined from the first color difference signal and the second color difference signal are output. The saturation C is calculated as in equation (1). As shown in FIG. 3, the outputs C and S for the inputs RY and BY are stored in the look-up table 1 within the hue range of the specific color, and 0 are stored outside the hue range of the specific color. The saturation C, the difference S, and the luminance signal Y are input to the specific color detection circuit 2, and the approximation signal A
P ′ and the detection signal D are obtained. The approximation signal AP 'has the maximum value of the representative value of the saturation range of the specific color and the representative value of the hue range of the specific color. Become. That is,
The approximation signal AP 'is larger for a color closer to the specific color and smaller for a color shifted from the specific color. The detection signal D is a sign bit of the approximation degree signal AP ′, and is negative if the specific color is 0 and 0 if the specific color is positive. The specific color detection circuit 2 operates as described in the first embodiment.

Next, the slice circuit 10 will be described. FIG.
As shown in FIG.
If H exceeds H, all outputs are set to H. That is, the approximation signal AP ′ is sliced by H. The sliced output is used as an approximation signal AP. Therefore, the approximation signal A
P changes slowly. As a result, it is possible to quantitatively detect the degree of approximation of a specific color.

Embodiment 3 FIG. FIG. 9 is a block circuit diagram showing a video signal processing device according to Embodiment 3 of the present invention. In FIG. 9, the same parts as those in FIG. 11 is a non-linear conversion circuit.

Next, the operation will be described. By inputting the RY color difference signal and the BY color difference signal to the look-up table 1, a saturation C and a difference S determined from the first color difference signal and the second color difference signal are output. The saturation C is calculated as in equation (1). As shown in FIG. 3, the outputs C and S for the inputs RY and BY are stored in the look-up table 1 within the hue range of the specific color, and 0 are stored outside the hue range of the specific color. The saturation C, the difference S, and the luminance signal Y are input to the specific color detection circuit 2, and the approximation signal A
P ′ and the detection signal D are obtained. The approximation signal AP 'has the maximum value of the representative value of the saturation range of the specific color and the representative value of the hue range of the specific color. Become. That is,
The approximation signal AP 'is larger for a color closer to the specific color and smaller for a color shifted from the specific color. The detection signal D is a sign bit of the approximation degree signal AP ′, and is negative if the specific color is 0 and 0 if the specific color is positive. The specific color detection circuit 2 operates as described in the first embodiment.

The nonlinear conversion circuit 11 will be described. Y
Since the three-dimensional space represented by the signal, the RY color difference signal, and the BY color difference signal is not a linear space when considered by human perception, the approximation signal AP ′ is not linear as a human perception amount. Therefore, as shown in FIG. 10, the change of the approximation signal AP ′ is converted by a non-linear conversion circuit 11 using a higher-order function, and is converted into an approximation signal AP corresponding to human perception. As a result, it becomes possible to detect the degree of approximation of the specific color as the perception amount.

Embodiment 4 FIG. FIG. 11 is a block circuit diagram showing a video signal processing device according to Embodiment 4 of the present invention. In the figure, the same parts as those in FIG. 12 is a filter.

Next, the operation will be described. By inputting the RY color difference signal and the BY color difference signal to the look-up table 1, a saturation C and a difference S determined from the first color difference signal and the second color difference signal are output. The saturation C is calculated as in equation (1). As shown in FIG. 3, the outputs C and S for the inputs RY and BY are stored in the look-up table 1 within the hue range of the specific color, and 0 are stored outside the hue range of the specific color. The saturation C, the difference S, and the luminance signal Y are input to the specific color detection circuit 2, and the approximation signal A
P ′ and the detection signal D are obtained. The approximation signal AP 'has the maximum value of the representative value of the saturation range of the specific color and the representative value of the hue range of the specific color. Become. That is,
The approximation signal AP 'is larger for a color closer to the specific color and smaller for a color shifted from the specific color. The detection signal D is a sign bit of the approximation degree signal AP ′, and is negative if the specific color is 0 and 0 if the specific color is positive. The specific color detection circuit 2 operates as described in the first embodiment.

The filter 12 will be described. When the filter 12 is, for example, a low-pass filter, as shown in FIG. 12, the rise of the approximation signal AP ′ from aY to dY and the fall from dY to bY are smoothly changed to obtain the approximation signal AP. As a result, it is possible to quantitatively detect the degree of approximation of a specific color.

Embodiment 5 FIG. FIG. 13 is a block circuit diagram showing a video signal processing device according to Embodiment 5 of the present invention. In the figure, the same parts as those in FIG. 13 is a first gain control circuit, 14 is a second gain control circuit, 15 is a first arithmetic circuit, and 16 is a second arithmetic circuit.

Next, the operation will be described. As described in the first embodiment, the approximation signal AP and the detection signal D are obtained from the specific color detection circuit 2. The RY color difference signal is input to the second gain control circuit 14 and the first arithmetic circuit 15, and the BY color difference signal is input to the first gain control circuit 13 and the second arithmetic circuit 16. When the detection signal D is 0, the first gain control circuit 13 and the second gain control circuit 14 control the gains of the BY color difference signal and the RY color difference signal in accordance with the magnitude of the approximation signal AP. . Then, the output of the first gain control circuit 13 is input to the first arithmetic circuit 15, and the output of the second gain control circuit 14 is input to the second arithmetic circuit 16. When the detection signal D is 0, the first arithmetic circuit 15 adds and subtracts the BY color difference signal to the RY color difference signal in accordance with the approximation signal AP, and the second arithmetic circuit 1
In step 6, the RY color difference signal is converted to the BY color difference signal by the approximation signal AP
, And outputs the respective calculation results as an RY color difference signal and a BY color difference signal. As a result, it is possible to move the hue of only a specific color, so that in a color video camera, a color that has been difficult to express due to the spectral sensitivity characteristics of the image sensor can be corrected to an appropriate color. Further, it is possible to correct a color different from the actual color, such as a human memory color such as a skin color.

Embodiment 6 FIG. FIG. 14 is a block circuit diagram showing a video signal processing device according to Embodiment 6 of the present invention. In the figure, the same parts as those in FIGS.

Next, the operation will be described. As described in the first embodiment, the approximation signal AP ′ and the detection signal D are obtained from the specific color detection circuit 2. For example, a signal obtained by slicing the approximation signal AP ′ by H by the slicing circuit 10 is output as the approximation signal AP. The RY color difference signal is input to the second gain control circuit 14 and the first arithmetic circuit 15, and the BY color difference signal is input to the first gain control circuit 13 and the second arithmetic circuit 16. When the detection signal D is 0, the first gain control circuit 13 and the second gain control circuit 14 control the gains of the BY color difference signal and the RY color difference signal in accordance with the magnitude of the approximation signal AP. . Then, the output of the first gain control circuit 13 is input to the first arithmetic circuit 15, and the output of the second gain control circuit 14 is input to the second arithmetic circuit 16. When the detection signal D is 0, the first arithmetic circuit 15 adds and subtracts the BY color difference signal to the RY color difference signal in accordance with the approximation signal AP, and the second arithmetic circuit 1
In step 6, the RY color difference signal is converted to the BY color difference signal by the approximation signal AP
, And outputs the respective calculation results as an RY color difference signal and a BY color difference signal. As a result, it is possible to move the hue of only a specific color, so that in a color video camera, a color that has been difficult to express due to the spectral sensitivity characteristics of the image sensor can be corrected to an appropriate color. Further, it is possible to correct a color different from the actual color, such as a human memory color such as a skin color. Since the change in the approximation signal AP is made gentle by the slice circuit 10, these color corrections can be performed with natural changes in which the boundaries are less noticeable.

Embodiment 7 FIG. FIG. 15 is a block circuit diagram showing a video signal processing device according to Embodiment 7 of the present invention. In the figure, the same parts as those in FIGS.

Next, the operation will be described. As described in the first embodiment, the approximation signal AP ′ and the detection signal D are obtained from the specific color detection circuit 2. For example, the non-linear conversion circuit 11 converts the approximation signal AP ′ by using a higher-order function, and outputs a signal obtained as a smooth change as the approximation signal AP. R-
The Y color difference signal is supplied to the second gain control circuit 14 and the first arithmetic circuit 1
5 and the BY color difference signal is input to the first gain control circuit 13 and the second arithmetic circuit 16. First gain control circuit 13
When the detection signal D is 0 in the second gain control circuit 14,
The gain of the BY color difference signal and the gain of the RY color difference signal are controlled in accordance with the magnitude of the approximation signal AP. Then, the output of the first gain control circuit 13 is input to the first arithmetic circuit 15, and the output of the second gain control circuit 14 is input to the second arithmetic circuit 16. When the detection signal D is 0, the first arithmetic circuit 15 adds or subtracts the BY color difference signal to the RY color difference signal according to the approximation signal AP, and the second arithmetic circuit 16 adds the BY color difference signal to the BY color difference signal.
The Y color difference signal is added or subtracted according to the approximation signal AP, and the respective calculation results are output as an RY color difference signal and a BY color difference signal. As a result, it is possible to move the hue of only a specific color, so that in a color video camera, a color that has been difficult to express due to the spectral sensitivity characteristics of the image sensor can be corrected to an appropriate color. Further, it is possible to correct a color different from the actual color, such as a human memory color such as a skin color.
3 represented by Y signal, RY color difference signal, and BY color difference signal
Since the dimensional space is not a linear space in terms of human perception, sufficient color correction cannot be performed by linear correction. Therefore, the non-linear conversion circuit 11 non-linearly converts the change in the approximation signal AP ′, and sets R as a correction amount corresponding to human perception.
By controlling the gains of the -Y color difference signal and the BY color difference signal, it is possible to perform the change with a natural change that makes the boundary less noticeable.

Embodiment 8 FIG. FIG. 16 is a block circuit diagram showing a video signal processing device according to Embodiment 8 of the present invention. In the figure, the same portions as those in FIGS. 11 and 13 are denoted by the same reference numerals, and description thereof will be omitted.

Next, the operation will be described. As described in the first embodiment, the approximation signal AP ′ and the detection signal D are obtained from the specific color detection circuit 2. For example, a high-frequency component of the approximation signal AP ′ is removed by the filter 12 and a smooth change is output as the approximation signal AP. The RY color difference signal is input to the second gain control circuit 14 and the first arithmetic circuit 15, and the BY color difference signal is input to the first gain control circuit 13 and the second arithmetic circuit 16. When the detection signal D is 0, the first gain control circuit 13 and the second gain control circuit 14 control the gains of the BY color difference signal and the RY color difference signal in accordance with the magnitude of the approximation signal AP. . Then, the output of the first gain control circuit 13 is input to the first arithmetic circuit 15, and the output of the second gain control circuit 14 is input to the second arithmetic circuit 16. When the detection signal D is 0, the first arithmetic circuit 15 performs RY
The BY color difference signal is added to and subtracted from the color difference signal according to the approximation signal AP, and the RY color difference signal is added to and subtracted from the BY color difference signal by the second arithmetic circuit 16 according to the approximation signal AP. The result is output as an RY color difference signal and a BY color difference signal. As a result, it is possible to move the hue of only a specific color, so that in a color video camera, a color that has been difficult to express due to the spectral sensitivity characteristics of the image sensor can be corrected to an appropriate color. Further, it is possible to correct a color different from the actual color, such as a human memory color such as a skin color. Since the change in the approximation signal AP is smoothed by the filter 12, these color corrections can be performed by natural changes in which the boundaries are less noticeable.

Embodiment 9 FIG. FIG. 17 is a block circuit diagram showing a video signal processing device according to Embodiment 9 of the present invention. In the figure, the same parts as those in FIG. 17 is a first bit shift circuit, 18 is a second bit shift circuit, 19 is a third bit shift circuit, 20, 2
Reference numerals 1 and 22 denote adders. However, the lookup table 1 in this embodiment has four ports for input and two ports for output.

In FIG. 3, the saturation C and the difference S determined from the RY color difference signal and the BY color difference signal are stored in the look-up table 1 within the hue range of the specific color, and 0 outside the hue range of the specific color. In this embodiment, as shown in FIG. 21, one bit is added to the most significant bit (MSB) as a hue range identification flag, and when the hue range identification flag is 0, the hue range is outside the hue range. Bits 1 to 3 store the difference S in the lookup table 1 and bits 4 to 8 store the value indicating the degree of saturation C in the lookup table 1. Therefore, in this embodiment, the specific color detection circuit 2 shown in FIG. 4 is configured as shown in FIG. The difference from FIG. 4 is that the zero comparator 7 becomes unnecessary, and instead, the MSB (hue range identification flag) output from the look-up table 1 is input to the OR gate 8 to determine whether or not the area is a specific color area. FIG. 17 will be described. For example, RY color difference signal,
The BY color difference signal has m bits. The structure of this signal is M
It is assumed that SB is a sign bit and negative is 1 and positive is 0. The remaining bits, both positive and negative, represent the absolute value of the value. That is, 01
01 is +5 and 1101 is -5. The RY color difference signal and the BY color difference signal are reduced by the first bit shift circuit 17 by p (p = m−1−n) bits into upper n bits RYn and BYn. Figure 1 shows these relationships.
FIG. The RYn and BYn are input to the lookup table 1 and only the saturation portion of the output value is input to the third bit shift circuit 19. In the third bit shift circuit 19, a value obtained by adding 0 for p bits to the input value is used as the saturation C1.
Output as Further, RYn and BYn are increased by p bits by the second bit shift circuit 18 and returned to the original digits, and the sign bits are removed, and RY and BY are respectively set. Since RY and BY are all 0 for the lower p bits, the RY and BY have absolute values smaller than the absolute values of the RY color difference signal and the BY color difference signal. Furthermore, the RY color difference signal and the BY
From the absolute value of the color difference signal excluding the sign bit, the adder 20,
21, RY and BY are subtracted respectively, and the lower p bits RYp and BYp of the RY color difference signal and the BY color difference signal are subtracted.
Get. RYp and BYp are values having a large absolute value (R-
Since the value (RY, BY) having a small absolute value is subtracted from (Y, BY), the sign is the same as that of the original signal (RY, BY). RYp and BYp are input to the look-up table 1 to obtain the saturation C2 excluding the MSB and the difference S. The adder 22 adds the saturations C1 and C2 to obtain the saturation C. For this reason, it is possible to reduce the capacity of the look-up table 1 and the calculation error.

The reason why the present embodiment obtains the above effects will be described. In FIG. 19, the saturation obtained by calculating the m-bit RY color difference signal and the BY color difference signal by equation (1) is C3. When this operation is performed by combining a multiplier and a divider, the circuit scale becomes large. Therefore, the saturation is calculated using a look-up table. Input m bits, output q
If it is a bit, the capacity of the lookup table is 2 ＾ 2m
Q bits are required. In a look-up table in which inputs are thinned out to upper n bits, 2 ＾ 2n · (q−
p) A bit capacity is required. Saturation degree C1 in this case
Is smaller than C3. At the saturation degree C1, the calculation error increases even if the capacity of the lookup table decreases. A method of reducing the calculation error is the present invention, and a description thereof will be given. RY color difference signal RYp for lower p bits
And the lower p bits of the BY color difference signal BYp are input to the look-up table 1 to obtain the saturation C2.
Look-up table 1 with input of Y color difference signal BYn
Is shifted by p bits to obtain the saturation C by adding the saturations C1 and C2 whose digits have been corrected. This saturation C is substantially equal to the saturation C3. The reason will be described. As shown in FIG. 19, when an angle between C1 and C3 is e and an angle between C2 and C3 is f, C1, C2, C
The relationship of 3 is as shown in equation (4). C3 = C1 · COS e + C2 · COS f (4) Here, e is a very small angle unless the look-up table is made extremely small. Further, when C2 is large, f is a small angle, and when f is large, C2 is very small with respect to C1, so that equation (5) is established. C3 ≒ C1 + C2 (5) Therefore, when the saturation is calculated by dividing the input into high-order bits and low-order bits as in the calculation method of the present embodiment and using each output, it is possible to reduce the calculation error. It becomes possible.

Embodiment 10 FIG. FIG. 22 shows Embodiment 10 of the present invention.
1 is a block circuit diagram showing a video signal processing device according to the present invention.
In the figure, the same parts as those in FIG. 23 is a comparator. However, the lookup table 1 in this embodiment has two ports for input and one port for output.

In FIG. 3, the saturation degree C determined from the RY color difference signal and the BY color difference signal is stored in the look-up table 1 within the hue range of the specific color, and 0 outside the hue range of the specific color. In this embodiment, as shown in FIG. 21, the most significant bit (M
SB), adding 1 bit as a hue range identification flag,
When the hue range identification flag is 0, the hue range is within the hue range. When the hue range identification flag is 1, the hue range is outside the hue range. . Therefore, in this embodiment, the specific color detection circuit 2 shown in FIG. 4 is configured as shown in FIG. The difference from FIG. 4 is that the zero comparator 7 becomes unnecessary, and instead, the MSB (hue range identification flag) output from the look-up table 1 is input to the OR gate 8 to determine whether or not the area is a specific color area. FIG. 22 will be described. For example, the RY color difference signal and the BY color difference signal have m bits. The structure of this signal is such that the MSB is a sign bit and the negative is 1 and the positive is 0. The remaining bits, both positive and negative, represent the absolute value of the value. That is, 0101 is +5,
1101 becomes -5. The RY color difference signal and the BY color difference signal are p (p = m−
1-n) RY for upper n bits reduced by bits
n, BYn. FIG. 18 shows these relationships. These RYn and BYn are input to the lookup table 1,
Only the saturation portion of the output value is input to the third bit shift circuit 19. The third bit shift circuit 19 outputs a value obtained by adding 0 for p bits to the input value as the saturation C1. Further, RYn and BYn are increased by p bits by the second bit shift circuit 18 and returned to the original digits, and the sign bits are removed, and RY and BY are respectively set. This R
Since Y and BY are all 0 for the lower p bits, RY
The absolute value is smaller than the absolute values of the color difference signal and the BY color difference signal. Further, RY and BY are subtracted by the adders 20 and 21 from the absolute values of the RY color difference signal and the BY color difference signal excluding the sign bit, and the RY color difference signal and the B
-Obtain RYp and BYp for the lower p bits of the Y color difference signal.
RYp and BYp are values having large absolute values (RY, B-
Since the value (RY, BY) having a small absolute value is subtracted from (Y), the sign is the same as that of the original signal (RY, BY). R
Yp and BYp are input to the comparator 23, and the larger one is set as the saturation degree C4. The saturation C is obtained by adding the saturation C1 and the saturation C4 by the adder 22. For this reason, it is possible to reduce the capacity of the look-up table 1 and the calculation error.

The reason why the present embodiment achieves the above effects will be described. In FIG. 19, the saturation obtained by calculating the m-bit RY color difference signal and the BY color difference signal by equation (1) is C3. When this operation is performed by combining a multiplier and a divider, the circuit scale becomes large. Therefore, the saturation is calculated using a look-up table. Input m bits, output q
If it is a bit, the capacity of the lookup table is 2 ＾ 2m
Q bits are required. In a look-up table in which inputs are thinned out to upper n bits, 2 ＾ 2n · (q−
p) A bit capacity is required. Saturation degree C1 in this case
Is smaller than C3. At the saturation degree C1, the calculation error increases even if the capacity of the lookup table decreases. A method of reducing the calculation error is the present invention, and a description thereof will be given. RY color difference signal RYp for lower p bits
And the lower p bits of the BY color difference signal BYp are compared with the comparator 2
3, the output of the look-up table 1 having the larger value C4, the RY color difference signal RYn for the upper n bits, and the BY color difference signal BYn for the upper n bits is input for p bits. obtaining a saturation C by adding the saturation C1 corrected digits by only bit shifting. This saturation C is substantially equal to the saturation C3. The reason will be described. As shown in FIG. 19, the angle between C1 and C3 is e, and C2 and C3 are
Assuming that the angle formed by 3 is f, the relationship between C1, C2, and C3 is as shown in equation (5) as shown in the ninth embodiment. further,
In equation (5), the same holds when C4 is added to C1 instead of C2. Therefore, when the saturation is calculated by dividing the input into upper bits and lower bits and using the respective outputs as in the calculation method of the present embodiment, the calculation error can be reduced.

In the ninth embodiment, four input ports and two output ports are used. However, if the reading speed of the lookup table 1 is sufficiently high, the frequency of the color difference signal for the upper n bits and the lower p bits is increased. It is also possible to have two input ports and one output port by inputting the data into the lookup table 1 in a time-division manner, synchronizing the output using a switch circuit and a delay circuit, and then adding and returning the frequency to be slowed down. It is. In the ninth and tenth embodiments, a signal for upper n bits and a signal for lower p bits are extracted using a bit shift circuit. However, in the case of a digital circuit, a signal line for upper n bits or a lower p bit is used. Only need to be extracted and directly input to the look-up table 1. In this case, the adders 20 and 21 become unnecessary. In the ninth and tenth embodiments, the output when the upper n bits are input is the output obtained by adding 0 for the p bits by the third bit shift circuit 19 and the output when the lower p bits are input. Is added by the adder 22, but in the case of a digital circuit,
By combining the signal lines of the respective outputs, a signal bit-shifted by p bits is added. In this case, the third bit shift circuit 19 and the adder 22 become unnecessary. Further, the look-up table 1 in the above embodiment is a ROM (Read Only Memory), a RAM (Random Acc
(Essue Memory) or a storage device such as a semiconductor device such as a CD, a magneto-optical disk, a magnetic disk, or a magnetic tape.

[0055]

According to the first aspect of the present invention, the saturation is compared with the representative value of the saturation range of the specific color, and when the saturation is larger than the representative value of the saturation range of the specific color, the specific value is determined. A value obtained by subtracting the difference between the upper limit value of the color saturation range and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output from the representative value of the saturation range of the specific color. Is also smaller,
To output a value obtained by subtracting the difference between the saturation and the lower limit value of the saturation range of the specific color from the representative value within the hue range of the specific color, quantitatively detecting the degree of approximation of the specific color. There is an effect that becomes possible.

According to the second aspect of the present invention, the saturation is compared with the representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, the saturation of the specific color is determined. A slice obtained by subtracting the difference between the upper limit of the saturation range and the representative value in the hue range of the specific color from the difference between the saturation and the slice is output, and the saturation is a representative value of the saturation range of the specific color. If smaller, the difference between the saturation and the lower limit of the saturation range of the specific color is subtracted from the difference between the representative value in the hue range of the specific color and sliced and output. There is an effect that the degree can be quantitatively detected.

According to the third aspect of the present invention, the saturation is compared with the representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, the saturation of the specific color is determined. A value obtained by subtracting the difference between the upper limit of the saturation range and the representative value in the hue range of the specific color from the difference between the saturation and the nonlinear conversion is output, and the saturation is representative of the saturation range of the specific color. If the value is smaller than the value, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is nonlinearly converted and output. There is an effect that it is possible to accurately detect the color and the degree of approximation of a specific color as a perceived amount.

According to the fourth aspect of the present invention, the saturation is compared with the representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, A value obtained by subtracting the difference between the upper limit value of the saturation range and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output through a low-pass filter or a band-pass filter, and the saturation is output for the specific color. If the saturation value is smaller than the representative value of the saturation range, the difference between the saturation and the lower limit value of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is determined by a low-pass filter or band-pass filter. Since the signal is output through the filter, the degree of approximation of the specific color can be quantitatively detected.

According to the fifth aspect of the present invention, if the color is within the specific color region, the saturation is compared with the representative value of the saturation range of the specific color, and the saturation is set within the saturation range of the specific color. If the difference is larger than the representative value, a value obtained by subtracting the difference between the upper limit of the saturation range of the specific color and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output as a correction amount. Is smaller than the representative value of the saturation range of the specific color, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is corrected. The first gain control means and the second gain control means are independently controlled in accordance with the magnitude of the correction amount, and color correction is performed only in a specific color area, so that other colors are affected. It is possible to perform color correction of specific colors with natural changes that make the boundaries less noticeable There is a result.

According to the sixth aspect of the present invention, if the color is within the specific color area, the saturation is compared with the representative value of the saturation range of the specific color, and the saturation is set within the saturation range of the specific color. If the difference is larger than the representative value, a value obtained by subtracting the difference between the upper limit of the saturation range of the specific color and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output as a correction amount. Is smaller than the representative value of the saturation range of the specific color, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is corrected. The correction amount is output as a first amount according to the size of the sliced output.
Since the gain control means and the second gain control means are independently controlled to correct only the specific color area, the color correction of the specific color can be performed with a natural change in which the boundary is less noticeable without affecting other colors. Has the effect of being able to perform

According to the seventh aspect of the present invention, if the color is within the specific color region, the saturation is compared with the representative value of the saturation range of the specific color, and the saturation is determined to be within the saturation range of the specific color. If the difference is larger than the representative value, a value obtained by subtracting the difference between the upper limit of the saturation range of the specific color and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output as a correction amount. Is smaller than the representative value of the saturation range of the specific color, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is corrected. The first gain control means and the second gain control means are independently controlled in accordance with the magnitude of the output obtained by nonlinearly converting the absolute value, and color correction is performed only for a specific color area. Color correction of specific colors with natural changes that make the boundaries less noticeable without affecting the color There is an effect that it becomes possible to perform.

According to the eighth aspect of the present invention, if the color is within the specific color area, the saturation is compared with the representative value of the saturation range of the specific color, and the saturation is determined to be within the saturation range of the specific color. If the difference is larger than the representative value, a value obtained by subtracting the difference between the upper limit of the saturation range of the specific color and the representative value within the hue range of the specific color from the difference between the saturation and the saturation is output as a correction amount. Is smaller than the representative value of the saturation range of the specific color, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value within the hue range of the specific color is corrected. The first gain control means and the second gain control means are independently controlled in accordance with the magnitude of the output obtained by passing the absolute value through a low-pass filter or a band-pass filter. To make corrections, more boundaries are visible without affecting other colors. Chinikui the effect of making it possible to perform the specific color of the color correction in a natural variation.

According to the ninth aspect of the invention, there is an effect that even if the capacity of the lookup table is reduced, the calculation error can be reduced.

According to the tenth aspect of the present invention, there is an effect that the calculation error can be reduced even if the capacity of the lookup table is reduced.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram illustrating a video signal processing device according to a first embodiment.

FIG. 2 is a diagram illustrating a relationship between a representative value of a hue range of a specific color and a hue of data to be written into a look-up table in Examples 1, 2, 3, and 4;

FIG. 3 is a diagram showing the contents of a look-up table 1 that stores the degree of saturation of a specific color area in Examples 1, 9, and 10;

FIG. 4 is a specific color detection circuit 2 according to the first, ninth, and tenth embodiments.
FIG. 3 is a diagram showing the configuration of FIG.

FIG. 5 is a diagram illustrating a specific color area in a three-dimensional space according to the first embodiment.

FIG. 6 is a diagram illustrating a relationship between an approximation signal AP and a detection signal D with respect to a saturation range of a specific color region in the first embodiment.

FIG. 7 is a block circuit diagram illustrating a video signal processing device according to a second embodiment.

FIG. 8 is a diagram illustrating a relationship between an approximation signal AP and a detection signal D with respect to a saturation range of a specific color region according to the second embodiment.

FIG. 9 is a block circuit diagram illustrating a video signal processing device according to a third embodiment.

FIG. 10 is a diagram illustrating a relationship between an approximation signal AP and a detection signal D with respect to a saturation range of a specific color region according to the third embodiment.

FIG. 11 is a block circuit diagram illustrating a video signal processing device according to a fourth embodiment.

FIG. 12 is a diagram illustrating a relationship between an approximation signal AP and a detection signal D with respect to a saturation range of a specific color region according to a fourth embodiment.

FIG. 13 is a block circuit diagram illustrating a video signal processing device according to a fifth embodiment.

FIG. 14 is a block circuit diagram illustrating a video signal processing device according to a sixth embodiment.

FIG. 15 is a block circuit diagram illustrating a video signal processing device according to a seventh embodiment.

FIG. 16 is a block circuit diagram illustrating a video signal processing device according to an eighth embodiment.

FIG. 17 is a block circuit diagram illustrating a video signal processing device according to a ninth embodiment.

FIG. 18 is a diagram illustrating a configuration of each bit of an RY color difference signal and a BY color difference signal in Examples 9 and 10.

FIG. 19 shows the saturation C when the capacity of the lookup table 1 in the ninth and tenth embodiments is 2 ＾ 2m · q bits.
3, and the capacity of the lookup table 1 is 2 ＾ 2n ·
The RY color difference signal and B-
The saturation C1 for the upper n bits of the Y color difference signal and the saturation C2 for the lower p bits of the RY color difference signal and the BY color difference signal.
FIG.

FIG. 20 is a diagram illustrating a configuration of a specific color detection circuit 2 according to the ninth and tenth embodiments.

FIG. 21 is a diagram showing the contents of a lookup table 1 storing saturation and a specific color identification flag in Examples 9 and 10.

FIG. 22 is a block circuit diagram illustrating a video signal processing device according to a tenth embodiment.

FIG. 23 is a block circuit diagram showing a conventional video signal processing device.

[Explanation of symbols]

 Reference Signs List 1 lookup table 2 specific color detection circuit 3 comparator 4 switch circuit 5, 6 adder 7 zero comparator 8 OR gate 9 adder 10 slice circuit 11 nonlinear conversion circuit 12 filter 13 first gain control circuit 14 second gain control Circuit 15 First operation circuit 16 Second operation circuit 17 First bit shift circuit 18 Second bit shift circuit 19 Third bit shift circuit 20, 21, 22 Adder 23 Comparator 24, 25, 26 Gain control circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-69291 (JP, A) JP-A-5-103335 (JP, A) JP-A-1-314087 (JP, A) JP-A-63-69291 177685 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 9/64-9/78

Claims (10)

(57) [Claims] 1. A video signal processing device for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein the first color difference signal and the second color difference signal are within a hue range of a specific color. The determined saturation, the first color difference signal and the second
A look-up table for outputting a difference between a hue determined from the hue difference signal and a representative value of a hue range of the specific color, and outputting a value that can be distinguished from the output value outside the hue range of the specific color; And the second color difference signal are input to the look-up table to determine whether the color is within the hue range and the saturation range of the specific color, and determine whether the color is within the hue range and the saturation range of the specific color. For example, a detection signal indicating a specific color area is output , and the saturation is compared with a representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, A value obtained by subtracting the difference between the upper limit of the color saturation range and the representative value of the hue range of the specific color from the difference between the saturation and the saturation is output, and the saturation is higher than the representative value of the saturation range of the specific color. If smaller, the saturation and the lower limit of the saturation range of the specific color Video signal processing device and outputs the minus the difference between the representative value of the hue range of the specific color from. 2. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein the first color difference signal and the second color difference signal fall within a hue range of a specific color. The determined saturation, the first color difference signal and the second
A look-up table that outputs a difference between a hue determined from the hue difference signal and a representative value of a hue range of a specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color; And the second color difference signal are input to the look-up table to determine whether the color is within the hue range and the saturation range of the specific color , and determine whether the color is within the hue range and the saturation range of the specific color. For example, a detection signal indicating a specific color area is output , and the saturation is compared with a representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, The difference between the upper limit of the color saturation range and the difference between the saturation and the representative value of the hue range of the specific color is sliced and output, and the saturation is representative of the saturation range of the specific color. If less than the value, the saturation and the saturation range of the specific color A video signal processing apparatus characterized by outputting the sliced minus the difference between the representative value of the hue range of the specific color from the difference between the lower limit value. 3. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein the first color difference signal and the second color difference signal fall within a hue range of a specific color. The determined saturation, the first color difference signal and the second
A look-up table that outputs a difference between a hue determined from the hue difference signal and a representative value of a hue range of a specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color; And the second color difference signal are input to the look-up table to determine whether the color is within the hue range and the saturation range of the specific color , and determine whether the color is within the hue range and the saturation range of the specific color. For example, a detection signal indicating a specific color area is output , and the saturation is compared with a representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, A value obtained by subtracting the difference between the upper limit of the color saturation range and the representative value of the hue range of the specific color from the difference between the saturation and the nonlinear conversion is output, and the saturation is the saturation of the specific color. If less than the representative value, the saturation and the saturation range of the specific color Video signal processing device and outputting non-linearly converting the minus the difference between the representative value of the hue range of the specific color from the difference between the lower limit of. 4. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein the first color difference signal and the second color difference signal are within a hue range of a specific color. The determined saturation, the first color difference signal and the second
A look-up table that outputs a difference between a hue determined from the hue difference signal and a representative value of a hue range of a specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color; And the second color difference signal are input to the look-up table to determine whether the color is within the hue range and the saturation range of the specific color , and determine whether the color is within the hue range and the saturation range of the specific color. For example, a detection signal indicating a specific color area is output , and the saturation is compared with a representative value of the saturation range of the specific color. If the saturation is larger than the representative value of the saturation range of the specific color, A value obtained by subtracting the difference between the upper limit value of the color saturation range and the representative value of the hue range of the specific color from the difference between the saturation and the saturation is output through a low-pass filter or a band-pass filter, and the saturation is output for the specific color. Less than the typical value of the saturation range In the case, the difference between the saturation and the lower limit of the saturation range of the specific color minus the difference between the representative value of the hue range of the specific color is output through a low-pass filter or a band-pass filter. Video signal processing device. 5. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein a first color difference signal is added to or subtracted from a second color difference signal.
Computing means, first gain control means for controlling the amount of addition / subtraction of the first color difference signal to / from the second color difference signal, second computing means for adding / subtracting the second color difference signal to / from the first color difference signal, A second gain control means for controlling an amount of addition and subtraction of the second color difference signal from the first color difference signal; a saturation determined from the first color difference signal and the second color difference signal within a hue range of the specific color; A lookup table that outputs a difference between a hue determined from the color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color. By inputting the first color difference signal and the second color difference signal to the look-up table, it is determined whether or not the color is within the hue range of the specific color. By comparing with the luminance signal, the saturation of the specific color Determine囲内or not, if the color in a hue range and saturation range of the specific color, and outputs a detection signal indicating a specific color area, the representative value of saturation range of the specific color and the saturation When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the representative value of the hue range of the specific color from the difference between the saturation and the saturation. Is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the hue of the specific color is calculated from the difference between the saturation and the lower limit of the saturation range of the specific color. A value obtained by subtracting the difference from the representative value of the range is output as a correction amount, and the first gain control means and the second gain control means are independently controlled in accordance with the magnitude of the correction amount, so that the specific color area A video signal processing device for performing color correction. 6. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein a first color difference signal is added to or subtracted from a second color difference signal.
Computing means, first gain control means for controlling the amount of addition / subtraction of the first color difference signal to / from the second color difference signal, second computing means for adding / subtracting the second color difference signal to / from the first color difference signal, A second gain control means for controlling an amount of addition and subtraction of the second color difference signal from the first color difference signal; a saturation determined from the first color difference signal and the second color difference signal within a hue range of the specific color; A lookup table that outputs a difference between a hue determined from the color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color. By inputting the first color difference signal and the second color difference signal to the look-up table, it is determined whether or not the color is within the hue range of the specific color. By comparing with the luminance signal, the saturation of the specific color Determine囲内or not, if the color in a hue range and saturation range of the specific color, and outputs a detection signal indicating a specific color area, the representative value of saturation range of the specific color and the saturation When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the representative value of the hue range of the specific color from the difference between the saturation and the saturation. Is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the hue of the specific color is calculated from the difference between the saturation and the lower limit of the saturation range of the specific color. A value obtained by subtracting the difference from the representative value of the range is output as a correction amount, and the first gain control means and the second gain control means are independently controlled according to the magnitude of the output obtained by slicing the correction amount, A video signal processing device for performing color correction of a specific color area. 7. A video signal processing apparatus for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein a first color difference signal is added to or subtracted from a second color difference signal.
Computing means, first gain control means for controlling the amount of addition / subtraction of the first color difference signal to / from the second color difference signal, second computing means for adding / subtracting the second color difference signal to / from the first color difference signal, A second gain control means for controlling an amount of addition and subtraction of the second color difference signal from the first color difference signal; a saturation determined from the first color difference signal and the second color difference signal within a hue range of the specific color; A lookup table that outputs a difference between a hue determined from the color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color. By inputting the first color difference signal and the second color difference signal to the look-up table, it is determined whether or not the color is within the hue range of the specific color. By comparing with the luminance signal, the saturation of the specific color Determine囲内or not, if the color in a hue range and saturation range of the specific color, and outputs a detection signal indicating a specific color area, the representative value of saturation range of the specific color and the saturation When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit of the saturation range of the specific color and the representative value of the hue range of the specific color from the difference between the saturation and the saturation. Is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the hue of the specific color is calculated from the difference between the saturation and the lower limit of the saturation range of the specific color. A value obtained by subtracting the difference from the representative value of the range is output as a correction amount, and the first gain control means and the second gain control means are independently controlled according to the magnitude of the output obtained by nonlinearly converting the correction amount. A video signal processing device for performing color correction of a specific color region. 8. A video signal processing device for processing a luminance signal, a first color difference signal, and a second color difference signal as a video signal, wherein a first color difference signal is added to or subtracted from a second color difference signal.
Computing means, first gain control means for controlling the amount of addition / subtraction of the first color difference signal to / from the second color difference signal, second computing means for adding / subtracting the second color difference signal to / from the first color difference signal, A second gain control means for controlling an amount of addition and subtraction of the second color difference signal from the first color difference signal; a saturation determined from the first color difference signal and the second color difference signal within a hue range of the specific color; A lookup table that outputs a difference between a hue determined from the color difference signal and the second color difference signal and a representative value of the hue range of the specific color, and outputs a value that can be distinguished from the output value outside the hue range of the specific color. By inputting the first color difference signal and the second color difference signal to the look-up table, it is determined whether or not the color is within the hue range of the specific color. By comparing with the luminance signal, the saturation of the specific color Determine囲内or not, if the color in a hue range and saturation range of the specific color, and outputs a detection signal indicating a specific color area, the representative value of saturation range of the specific color and the saturation When the saturation is larger than the representative value of the saturation range of the specific color, the difference between the upper limit value of the saturation range of the specific color and the saturation and the representative value of the hue range of the specific color from the difference between the saturations. Is output as a correction amount, and when the saturation is smaller than the representative value of the saturation range of the specific color, the hue of the specific color is calculated from the difference between the saturation and the lower limit of the saturation range of the specific color. A value obtained by subtracting the difference from the representative value of the range is output as a correction amount. The first gain control means and the second gain control means output the correction amount through a low-pass filter or a band-pass filter according to the magnitude of the output. Perform independent color correction for specific color areas A video signal processing apparatus according to claim. 9. The contents of a look-up table provided in the video signal processing device according to any one of claims 1 to 8, wherein the content of the look-up table is a saturation determined from the first color difference signal and the second color difference signal, and the first color difference signal and the second color difference signal. a hue determined from the second color difference signal and the difference between the representative value of the hue range of the specific color, Ri distinguishing color gamut identification flag der whether out hue range or within a hue range of the specific color, the first color difference signal and the If the two color difference signals are within the hue range of the specific color, the upper n bits of the m-bit first color difference signal and the m-bit second color difference signal are input to the look-up table, respectively, and the output is saturated. The first saturation is obtained by increasing the degree portion by mn bits , and the lower mn bits of the first color difference signal and the lower mn bits of the second color difference signal are respectively looked up. Saturation part of output obtained by input to table A video signal processing apparatus characterized in that the sum of the first and second saturations is used as a saturation determined from a first color difference signal and a second color difference signal. 10. The contents of a look-up table provided in the video signal processing device according to claim 1 are a saturation determined from a first color difference signal and a second color difference signal, and a first color difference signal and a second color difference signal. a hue determined from the second color difference signal and the difference between the representative value of the hue range of the specific color, Ri distinguishing color gamut identification flag der whether out hue range or within a hue range of the specific color, the first color difference signal and the When the two color difference signals are within the hue range of the specific color, the m-bit first color difference signal and the m-bit second color difference signal
And the upper n bits of the color difference signals input to the look-up table, respectively, those of the saturation portion of the output was increased by m-n bits to a first saturation, lower first color difference signal m- The n bits and the lower mn bits of the second color difference signal are compared by a comparator, and the larger one is added to the first saturation, and the saturation determined from the first color difference signal and the second color difference signal. A video signal processing device.