Speckle filtering and texture analysis in SAR images

The presence of speckle in radar images makes the radiometric and textural aspects less efficient for class discrimination. Many adaptive filters have been developed for speckle reduction. In this study, the most well-known and promising filters have been analysed. Some modifications have then been introduced to the refined gamma-map filter in order to improve its filtering effectiveness. This has stemmed from a proposed refined speckle filtering algorithm for SAR images which ensures reliable local statistics estimation, edge enhancement and preservation of both textural and curvilinear features. In these modifications the determination of the speckle coefficient of variation and the orientation of a possible edge or linear feature have been carried out in a more practical and holistic manner to avert the imperfections in the existing filter