Image Enhancement Based on Nonsubsampled Contourlet Transform

Based on nonsubsampled contourlet transform and image statistical property, an image enhancement method is presented. A 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 estimates the variance in each decomposed direction, and the directional local neighborhood statics is used to distinguish the strong edge, wake edge and noise. The wake edge is enhanced and the speckled noise is reduced. Experimental results show that the method represents better performance in wake edges information enhancement and speckle reduction.