Abstract
An adaptive image filtering scheme is presented for edge and contrast enhancement. This filtering technique is based on a sliding window, which moves across the image in both vertical and horizontal directions. At each step, the density value of the center pixel in the window is transformed to a new value via the filtering equation. This algorithm is superior to that of unsharp masking, a technique reported in the past few years, in the sense that it does not uniformly enhance the high frequency noise components of the image for the sake of edge enhancement. Since the parameters of this filtering algorithm are adaptively adjusted according to the statistics of the local area (window), there are no user (operator) interactions required. The relation between the size of the sliding window, the degree of enhancement, and the stability of the filter are shown in applications concerning visualization of digital angiograms and chest radiographs.