| 摘要 |
PROBLEM TO BE SOLVED: To provide a color image signal processing method for suppressing a large change in the hue of a skin color at over exposure or an under exposure. SOLUTION: The color image signal processing method includes a step (a) of capturing image signal data of an original color system or a complementary color system; a step (b) of converting the image signal data into data of luminance Y and color difference signals Cr, Cb in the Y-Cr=Cb space; and an arithmetic step (c) of using at least one of formulae 1 to 4 to calculate a color difference matrix arithmetic operation. The formulae are Cr'=Cr×A/K +Cb×B (1), Cr'=(Cr×A+Cb×B)/K (2), Cb'=Cr×C+Cb×D×K (3), and Cb'=(Cr×C+Cb×D)×K (4), where A, B, C and D are color difference matrix coefficients, K is a function of Y and a correction coefficient greater than 0, K is decided so that a color difference ratio H(=Cr'/Cb') is constant independently of the luminance Y, and Cr' and Cb' are color difference signals after the correction. |
