Patent ID: 7657087

Claim:
A method implemented in a computing device for determining whether an input pixel in a color space coordinate system is a flesh-tone pixel, wherein said method when executed by the computing device, causes the computing device to perform a plurality of steps comprising: (a) defining a flesh-tone axis in said color space coordinate system, wherein said color space coordinate system includes an origin, a first coordinate axis and a second coordinate axis, and said flesh-tone axis passes through a center of a flesh-tone region and the origin of said color space coordinate system; (b) calculating a perpendicular point on said flesh-tone axis, said perpendicular point having the shortest distance to an input pixel; (c) calculating a first distance between said input pixel and said perpendicular point projected on the first coordinate axis, and a second distance between said perpendicular point and the center of said flesh-tone region projected on the first coordinate axis; and (d) determining that said input pixel is a flesh-tone pixel if said first distance is smaller than a first threshold value and said second distance is smaller than a second threshold value, wherein said first threshold value is proportional to an acute angle between said flesh-tone axis and the second coordinate axis, and said second threshold value is proportional to an area of said flesh-tone region.