Image Contrast Enhancement Based on Differential Gray Level of Gradient Pixels Pair

Abstract

This paper proposes a method for image contrast enhancement by using not only the distribution of gray levels but also the spatial features included in an objective input image. A contour appears on the boundary between the two planes that have different gray levels. For image contrast enhancement, expanding the difference of the gray levels in the planes that locates on both sides of the contour is supposed to be effective. By expanding the subtraction between the gray levels in the neighboring planes, the contour becomes conspicuous by visual. Therefore, the difference between the gray levels of the pixels pair is treated as the weight for contrast enhancement in the proposed method. The resultant image by the proposed method had better contrast and less noises than the conventional methods.