Medical Image Enhancement based on Adaptive Histogram Equalization and Contrast Stretching

Abstract

Image enhancement techniques aim to improve the quality of images. In field of medical image processing, low contrast is considered as one of the main and most important issues. As Histogram Equalization (HE) is an effective and simple technique, it is widely used as contrast enhancement. In this paper, efficient method to enhance the quality of medical images has been proposed. This method depends on Discrete Wavelet Transform (DWT) to decompose an input image as the first step. HE and contrast stretching were carried out on the results of DWT separately. Adaptive Histogram Equalization (AHE) was applied on the main part that is resulted from DWT. Contrast stretching was applied on the remaining parts. The results that been gotten showed goodness and efficiency of the proposed method.