Edge extraction is one of the most important components of multisensor information fusion.For SAR images the performance of conventional edge extraction methods such as those based on zero crossings of the second order derivatives is terribly bad due to the existence of speckle.Based on the analysis of the characteristics of synthetic aperture radar(SAR)images

this paper puts forward a combined method for edge extraction of SAR images

which is composed of wavelet transform and fuzzy weighted median filter.Wavelet can be used for edge detection because multiresolution wavelet decomposition of an image yields detailed coefficients that contain the high frequency content of the image.Median filter is a kind of nonlinear filters that has good ability in keeping edge.The experimental results show the effectiveness and stability of the method.The examples of SAR image edges and visible light image edges are given and analyzed respectively.Furthermore

these edges are used for image matching.The precision of location can come to 1 pixel.