A Blind Watermarking Using Orthogonal Finite Ridgelet Transform and Fuzzy C-Means

Abstract

Based on energy distribution analysis of orthogonal FRIT coefficients, a novel digital image watermark embedding and blind detecting algorithm in ridgelet domain is proposed in this paper. Since the ridgelet transform has directional sensitivity and anisotropy, the image is first partitioned into small pieces and the orthogonal FRIT is applied for each piece to obtain a sparse representation of the image, especially for straight edge singularity. Through analyzing texture distribution in ridgelet coefficients of each piece, these image pieces are classified into frat regions and texture regions by Fuzzy C-Mean (FCM) clustering algorithm. The texture regions used for watermark embedding also classified into two regions, strong texture regions and week texture regions for different embedding strengths based on the features of luminance masking and texture masking. And the watermarks can be blindly detected without the original image and watermark information. Experimental results show that the proposed watermarking scheme can achieve a better tradeoff between the robustness and the transparency.