Gamma correction with revised piecewise curve and edge directed error diffusion

摘要

Gamma correction is an indispensable process due to the nonlinear I/O characteristics of modern display devices such as CRT and LCD. However, coarse and imprecise gamma correction degrades the image quality significantly by causing false contours in the low luminance regions. This paper proposes a new gamma correction method with error diffusion. This method employs a relatively small LUT, while providing an efficient and precise way for indexing the gamma corrected values. Moreover, we adopt a revised piecewise gamma correction curve to enhance the contrast of the dark area and make error diffusion in an edge directed strategy. Experiment results indicate this method gives good performances in gamma correction, especially for the dark area of images.