SAR image edge detection by ratio-based Harris method

The presence of speckle, which modeled as a strong multiplicative noise, makes the edge detection of synthetic aperture radar (SAR) images very difficult. The usual edge detectors using gradient yield poor results. By analyzing Harris' combined corner and edge detector, to solve the speckle-sensitivity and anisotropic response, an edge detection method used for SAR image is presented. Horizontal, vertical and diagonal ratios of averages of non-overlapped neighboring pixel values instead of gradients are used to calculate edge strength maps (ESM); then they are fused to obtain the final ESM; finally, a threshold is presented to obtain edge detection result. Analysis and experiment results illustrate that the proposed method can be used for edge detection in SAR image effectively.