An effective preprocessor for enhancing edge detection in speckle images

Edge detection is an intuive stragety to figure out an object in digital images. Nevertheless, if an image is spread with noise such as ultrasonic noise, scanner noise or camera noise, general edge detectors can not perform effectively. In this paper, a preprocessor is provided to handle this issue. For each pixel in a speckle image, the preprocessor first determines whether it is a noise or not. It then checks if it is located on an edge. According to the information, the preprocessor can define different weighted coefficients to equalize each pixel. After that, we can perform an edge detection mechnism on the processed image to draw the edge map. Experimental results show that the preprocessor is able to effectively enhance the performance of edge detection mechanims in speckle images.