System and method for contrast extension adjustment and overflow compensation of image signal

Abstract

This invention provides a system and method for image signal contrast extension and overflow compensation. The system includes contrast extension and overflow compensation look-up tables, an image gray level boundary determining unit, a contrast extension unit, an overflow judging unit, and an overflow compensation unit. The image gray level boundary determining unit defines a maximum and a minimum among the gray levels of the pixels of an image signal and calculates the difference. The contrast extension unit selects corresponding parameter from the contrast extension table for contrast extension of a given image pixel. The overflow judging unit judges whether the pixels are overflowed. The overflow compensation unit compensates the pixel. When a pixel is overflowed, the overflow compensation unit selects, according to the gray level of the pixel, a corresponding overflow compensation parameter to reduce the gray level to overcome the problem of overflow.