Performance Evaluation of Block Based Svd Image Watermarking

This paper presents a block based digital image watermarking algorithm that is dependent on the mathematical technique of singular value decomposition (SVD). Traditional SVD watermarking already exists for watermark embedding on the image as a whole. In the proposed approach, the original image is divided into blocks, and then the watermark is embedded in the singular values (SVs) of each block, separately. The watermark embedding on a blockby- block basis makes the watermark more robust to the attacks such as noise, compression, cropping and lowpass filtering as the results reveal. The watermark detection is implemented by extracting the watermark from the SVs of the watermarked blocks. Extracting the watermark from one block at least is enough to ensure the existence of the watermark.