Filtering of radar images for geological structural mapping
Catherine Méring, Jean‐François Parrot · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
Geological structural features may be described on satellite images as thin lines or contours. The extraction of these features is usually performed by enhancement techniques such as filtering and edge detection. However, radar images being characterized by the presence of speckle noise, the classical enhancement techniques do not provide good results in this case. We present here two methods of filtering based on local transformations of the gray-tone function. They provide gray-tone images where the speckle is removed and the continuity and sharpness of thin structures are preserved. The valuation of the methods is done by analyzing the binary images resulting from an automatic thresholding of the filtered images according to two criteria: homogeneity and connectivity.