An adaptive SAR image speckle reduction algorithm based on wavelet transform and partial differential equations

Aiming at the structural feature and resolution preservation in speckle reduction of SAR image, an improved algorithm of speckle reduction which combines the adaptive wavelet soft-thresholding operation with partial differential equations (PDE) operation is proposed in this paper. Firstly, for suppressing the speckle noise primarily, the method of adaptive wavelet soft-thresholding operation based on statistical characteristics of sub-blocks is used. SAR image is divided into sub-blocks and the most homogeneous sub-block is chosen to calculate the threshold. Secondly, the PDE operation is used to suppress the residual noise. The effectiveness of the algorithm is verified by the experiments with the HJ1C SAR image.