Due to the presence of speckle,which can be modeled as a strong,multiplicative noise,edge detection in synthetic aperture radar(SAR) images is extremely difficult.We propose a new step-edge detector for SAR images,which is search of the best local adaptive Gabor filter based on ROEWA.Edge directions are determined by multi-direction characteristics of Gabor filter.At the same time,errors of edge directions are rectified by maximum likelihood estimation.By combination of the visual cells octave a...