New Improved Filters for the Contourlet Transform with Application in Image Denoising
 
New Improved Filters for the Contourlet Transform with Application in Image Denoising ■
 
Alin Alecu, Alin Alecu, Alin Alecu, Adrian Munteanu, Adrian Munteanu, Adrian Munteanu, Alexandra Pizurica, Alexandra Pizurica, Alexandra Pizurica, Jan Cornelis, Jan Cornelis, Jan Cornelis, Peter Schelkens, Peter Schelkens, Peter Schelkens
 
Abstract ■

In this paper we propose new filters for the contourlet transform and derive a series of trigonometric filters. Furthermore, we propose a methodology for designing new filters that are obtained from polynomial functions. Thus, we jointly derive different filters for each contourlet decomposition level, and apply them in image denoising. We show that on all the tested images and noise levels, the contourlet transform equipped with the proposed filters clearly outperforms its raised cosine filter-based counterpart in terms of denoising performance. In this sense, when employing polynomial filters, we report gains of up to 0.6dB.