Patent ID: 7724396

Claim:
A method for dithering image data, suitable for representing A-bit grayscale levels with a B-bit resolution, where A and B are positive integers and A>B, the method for dithering image data comprising: designating a corresponding target grayscale value within an interval from greater than or equal to 0 to less than or equal to (2 B −1)*2 A−B for each signal grayscale value from 0 to 2 A −1, wherein the 2 A target grayscale values form a strictly increasing sequence, and if expressed in binary, each of the target grayscale values has A integer digits and C decimal digits, where C is a positive integer; wherein if the signal grayscale value to be represented is X, obtaining the target grayscale value Y corresponding to the signal grayscale value X according to the correspondence between the 2 A signal grayscale values and the 2 A target grayscale values; and representing the target grayscale value Y with 2-dimensional dithering on a display device with the B-bit resolution.