In order to overcome the shortcomings of the conventional local statistical speckle filters for synthetic aperture radar (SAR) images,a combined despeckling algorithm is proposed based on region classification,adaptive windowing,and structure detection.Firstly,the combined despeckling algorithm classifies the local region and directly preserves the strong edges and structures as well as the point targets.Then,the homogeneous region and the weak edge and structure region grow adaptively to obtain appropriate filtering windows.Lastly,the new filtering windows are classified.For the homogeneous region,the averaged filter is directly used.For the edge and structure region,the structure information is detected and the homogeneous sub-window is selected as the final filtering region.Despeckling experiments demonstrate that,the combined despeckling algorithm effectively suppresses the speckles in homogeneous region and edge region,and well preserves the strong edge and structure information as well as the point targets.