Patent ID: 7227990
Filing Date: 2007-06-05
Classification: G06T,H04N

Abstract:
1. A color image processing device comprising: a color space converter for converting image signals to luminance signals corresponding to luminance and first and second chromaticity signals corresponding to chromaticity; a luminance signal correcting unit for correcting the luminance signal of a target pixel based on an average luminance signal obtained from luminance signals of the target pixel and predetermined pixels surrounding the target pixel in an x-y plane where x is in a main scanning direction and y is in a sub-scanning direction, and a saturation signal corresponding to saturation of the target pixel; a chromaticity signal correcting unit for correcting a color space inverter for inverting the corrected luminance signal, the corrected first chromaticity signal and the corrected second chromaticity signal to image signals; and a saturation calculator for generating a saturation signal of the target pixel based on the first and second chromaticity signals; an average saturation calculator for generating the average saturation signal based on the first and second average chromaticity signals; and a hue difference calculator for generating the hue difference signal based on the first and second chromaticity signals as well as the first and second average chromaticity signals; wherein the chromaticity signal correcting unit comprises a color correcting factor calculator for determining the chromaticity correcting level for correcting the first and second chromaticity signals of the target pixel based on the saturation signal of the target pixel, the average saturation signal and the hue difference signal; and wherein the color correcting factor calculator determines the chromaticity correcting level according to a first equation, when the hue difference signal is smaller than a hue difference threshold and determines the chromaticity correcting level according to a second equation, different from the first equation, when the hue difference signal is greater than the hue difference threshold.