Contourlet:Efficient Directional and Multiresolution Analytic Tool

The Contourlet transform is a new extension to wavelet transform in two dimensions using nonseparable and directional filter banks.With rich set of basis images oriented at varying directions in multiple scales,Contourlet transform can effectively capture the smooth contours,which are the dominant features in natural images,with only a small number of coefficients.This paper discussed the background,principles,digital realization and the application of Contourlet transform.Based on an analysis of the current problems within Contourlet transform,its further research directions has been anticipated.