Video signal processor for detecting flesh tones in am image

A video signal processor receiving a luminance signal and color-difference signals as video signals, comprising:

• first means for outputting a value based upon the received color-difference signals by referencing a predetermined table;
• second means for comparing the output value with the luminance signal and outputting a result of the comparison;
• third means for extracting only low-frequency components from the result of the comparison;
• fourth means for slicing the extracted low-frequency components by a predetermined slice level and outputting a resultant signal as a flesh-tone detection signal;
• and
• fifth means for controlling the gains of the plurality of color-difference signals, independently, in accordance with a value of the flesh-tone detection signal.

A video signal processor receiving a luminance signal and color-difference signals as video signals, comprising:

• first arithmetic means for adding a first color-difference signal to, or subtracting the first color-difference signal from, a second color-difference signal;
• first gain control means for controlling an amount of the first color-difference signal to be added to or subtracted from the second color-difference signal;
• second arithmetic means for adding the second color-difference signal to, or subtracting the second color-difference signal from, the first color-difference signal;
• second gain control means for controlling an amount of the second color-difference signal to be added to or subtracted from the first color-difference signal;
• first means for outputting a signal based upon the first and second color-difference signals by referencing a predetermined table;
• second means for comparing the output signal with the luminance signal and outputting a result of the comparison;
• third means for extracting only low-frequency components from the result of the comparison;
• fourth means for slicing the extracted low-frequency components by a predetermined slice level and outputting a resultant signal as a flesh-tone detection signal;
• and
• fifth means for controlling said first and said second gain control means, independently, in accordance with a value of the flesh-tone detection signal.

A method of adjusting a color difference signal of an image in a video signal processor comprising the steps of:

• (a) detecting flesh tone in areas of the image based upon a luminance signal and saturation level of the color difference signals of the image and generating a flesh tone detecting signal;
• and
• (b) controlling gains of the color difference signals based upon the generated flesh tone detecting signal;
• wherein the step (a) includes the substeps of:
• (i) receiving, in a memory, the color difference signals of the image,
• (ii) outputting a signal indicative of color signal saturation level from the memory, based upon the received color difference signals;
• (iii) comparing the output signal from the memory and the luminance signal;
• and
• (iv) outputting a signal indicative of flesh-tone or non-flesh-tone in an area of the image based upon the comparison of step (iii).

A method of adjusting a color difference signal of an image in a video signal processor comprising the steps of:

• (a) detecting flesh tone in areas of the image based upon a luminance signal and saturation level of the color difference signals of the image and generating a flesh tone detecting signal;
• and
• (b) controlling gains of the color difference signals based upon the generated flesh tone detecting signal;
• wherein step (a) includes the substeps of:
• (i) outputting a signal indicative of color signal saturation level based upon the color difference signals;
• and
• (ii) comparing the output signal and the luminance signal to produce a signal indicative of flesh tone or non flesh tone in an area of the image.

A method of adjusting a color difference signal of an image in a video signal processor comprising the steps of:

• (a) detecting flesh tone in areas of the image based upon a luminance signal and saturation level of the color difference signals of the image and generating a flesh tone detecting signal;
• and
• (b) controlling gains of the color difference signals based upon the generated flesh tone detecting signal;
• and wherein step (a) includes the steps of:
• (i) utilizing the color difference signals to access a table pre-stored in memory;
• and
• (ii) comparing the accessed value to the luminance signal to generate a signal indicative of flesh tone or non-flesh tone in an area of the image.