Edge detection using histogram equalization and multi-filtering process

Edge detection plays a critical role in image processing The performance of an edge detection algorithm can be affected by serious noise & intensity inhomogeneities. In this paper, a method aiming at detecting edge of image with varieties of gradient signal degradation is proposed. The method comprises two steps. The first step is to perform adaptive histogram equalization to improve the signal contrast in a discriminative manner. To this end, the histogram of the input image is analysed and the irregularity of image intensity, if there is any, is identified and removed by using a contrast limited adaptive histogram equalization technique. The following step is a gradient modulation filtering process with the modulation factor determined by the local intensity. The simulation results comprising subjective and objective analysis show that the pro- posed method is applicable and effective to detect edges of low-quality images.