SAR Image Enhancement Based on Nonsubsampled Contourlet Transform
Sha Yu-heng;Liu Fang; Jiao Li-cheng
Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education of China, Institute of Intelligent Information Processing, Xidian University, Xi’an 710071, China
Abstract:Based on nonsubsampled Contourlet transform and SAR image statistical property, a SAR image enhancement method is proposed. A speckle noise variance estimate algorithm is given using nonsubsampled Laplace Pyramid decompose, and a wake edge enhancement algorithm using directional local neighborhood is proposed. This paper estimate the speckle variance in each decomposes direction, and the directional local neighborhood statistical is used to distinguish the strong edge, wake edge and noise. The wake edge is enhanced and the speckled noise is restrained. Experiment results show that the method represents better performance compared with NSWT in wake edges information enhancement and speckle reduction.