An Insitu Single-pointed Wavelet-based Method for Noise Reduction in Sar Images

Speckle noise caused by interference of electromagnetic waves complicates Synthetic aperture radar (SAR) images to be interpreted and further practical application, therefore reducing speckle noise and preserving more detailed information are indispensable tasks in pre-processing. In this paper, a new insitu single-pointed (ISPW) method based on wavelet decomposition to several scales to suppress speckle noise was introduced. On the basis that pixels in log-transformed images are mutually independent, we operate insitu operations on wavelet coefficients in both approximate and detailed parts in each scale according to distribution of approximate component in each wavelet decomposition scale, while not affecting others’ in order to remove more speckle noise as well as preserve more original edge information. Several evaluation criteria are applied to examine the performance of this ISPW method. Results of experiments show that ISPW method can give a better visual quality and obtain a higher signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR) and edge preserving ability (EPA) as well.