SAR image speckle reduction algorithm based on second wavelet packet transform

According to the different characteristics that signal and noise exhibit during the wavelet decomposition, a new denoising method based on the second wavelet packet decomposition is presented. In this paper, by using the best wavelet packet, the synthetic aperture radar (SAR) images are decomposed and the norm of each sub-band is calculated. Then signals and noise can be discriminated and the images can be denoised based on the norm and soft-threshold ways. Experiments show that the proposed algorithm is of excellent performance in denoising SAR images, and can remove most noise of images with well-kept texture detail information. The calculating speed of the method is twice the speed of the general wavelet packet transform algorithm.