Brightness preserving contrast enhancement of medical images using adaptive gamma correction and homomorphic filtering

Abstract

In this paper we propose an efficient method to enhance contrast of medical images. Image contrast enhancement is a pre-processing step that improves efficiency of other image dealing applications such as pattern recognition and computer vision. The proposed method enhances contrast and preserves brightness of given image using the gamma correction and homomorphic filtering. This method uses two step processing, in first step global contrast of image is enhanced using the gamma correction and weighted probability distribution of luminance pixels and then in second step homomorphic filtering is used for image sharpening, in order to preserve image brightness this filtering if followed by image normalization. Experiments results show that the proposed method is able to enhance contrast of medical images without much affecting its brightness. This makes the proposed algorithm to be a flexible tool for medical image enhancement.