对图像进行非邻域滤波，调节参数后，能使得SAR图像接近光学图像-It is a non local filter. Using it , the SAR images can be approximated to optical one

usefull function to calculat ENL in SAR image denoising ,we computed the equivalent number of looks (ENL), a standard parameter widely used in the remote sensing community which measures the speckle reduction in homogeneous areas. with some SAR i