Patent ID: 7375854

Claim:
A method for color correction including: (1) the gray levels and the luminance values of a light source of a display device being measured by a color measurement system; (2) the gray levels and luminance values being normalized and N groups of gray levels (P) and luminance values (Q) being selected, wherein N is a positive integer and 2≦N≦maximum of what the display device can display; (3) each n groups of selected values being taken as an interval, wherein n is a positive integer and 2≦n ≦N; (4) the gray levels (P) and the luminance values (Q) of each interval being executed by logarithmic and divisional operations to obtain a gamma parameter: γ=log Q/log P, then a fitting function of the gamma parameter for each interval being able to be obtained, which can fit all selected data of the interval; (5) a fitting luminance value of each gray level in interval being able to be obtained from the fitting function of the gamma parameter for each interval of each color light of the light source, and then a lookup table consisted of gray levels and their corresponding fitting luminance values being able to be made; (6) original gray data of an image being normalized to obtain a gamma curve consisted of gray levels (X) and luminance values (Y) of each color light of the light source, where the function of the gamma curve is Y=X γ , and γ represents the gamma parameter; (7) the image gray signals of the function of the gamma curve Y=X γ being corresponded to a function of a predetermined target curve Yt=Xt γ′ , letting Xt=X and obtaining a modified gray signals by an iteration method, its steps including: (a) the gamma curve function and the target curve function being executed logarithmic and divisional operations, i.e. log Yt=(γ′/γ)log Y, to obtain a target luminance value Yt; (b) obtaining a transitional luminance value Yn corresponding with transitional gray levels Xn from the lookup table; (c) comparing the transitional luminance value Yn with the target luminance value Yt, if the difference between them is smaller than a tolerable error, then the target luminance value Yt and the target gray level Xt being substituted by the transitional luminance value Yn and transitional gray level Xn, respectively, if the difference between them being larger than a tolerable error, then the steps (a) to (c) mentioned above being repeated; and (d) transmitting the gray signals processed through steps (a) to (c), and the display device expressing a gray distribution state according to the modified gray signals.