| Abstract: | This paper presents a robust algorithm for digital image watermarking based on Singular Value Decomposition (SVD) and Dither Quantization. The eigen matrix in the singular value decomposition is explored for data embedding. The perceptibility of the watermarked image is enhanced by embedding the watermark image in some selected and most complex blocks of the host image. A block is said to be a complex block, if the number of edges in the block is more than a predefined threshold. The proposed method is robust and the watermark image can survive to many image attacks like rotation, scaling, noise, JPEG compression, JPEG 2000 compression, low pass filtering, biplane removal, row column blanking, row column copying, cropping, image tampering and gamma correction. Results are compared with an existing and recent method and found to be superior in terms of the quality of the extracted watermark image and resilience to attacks. The metric used to test the robustness of the proposed algorithm is the Normalized Cross correlation (NC).
|