Patent ID: 7447355

Claim:
A method for defining a plurality of chromaticity regions according to luminance levels and adjusting chromaticity of images accordingly, the method comprising the steps of: (a) defining a plurality of chromaticity regions according to a variety of luminance levels; and (b) multiplying an original chromaticity vector of a pixel with an adjusting factor to form an adjusted chromaticity vector, the original chromaticity vector of the pixel corresponding to one of the chromaticity regions set in step (a), which corresponds to a luminance level of the pixel, wherein the chromaticity regions comprise a first chromaticity region corresponding to a first luminance level larger than 60 but not larger than 175, a pixel having a chromaticity vector within the first chromaticity region having a first chromaticity component and a second chromaticity component conforming to the following constraints: 2*C b −3*C r <−64, 2*C b −3*C r >−288, C b +C r >−12, and 2*C b +C r <24, where C b is the first chromaticity component and C r the second chromaticity component.