CEW: A non-blind adaptive image watermarking approach based on entropy in contourlet domain

This paper presents a new approach for non-blind watermarking of still gray level images in contourlet domain. It uses the Human Visual System (HVS) characteristic, and an innovative entropy based approach to create an efficient watermarking scheme. It decomposes original image in contourlet domain in four hierarchical levels and watermarks it with a logo image, which is scrambled thru a well-known PN-sequence. A novel entropy-based method is developed for selection of contourlet coefficients that provides an adaptive way for determining the number of watermarked coefficients and watermarking factor at each level of contourlet decomposition. This approach shows resistance against some attacks presented in the watermarking literature.