Use of singular value decomposition for digital image watermarking

Watermarking, is the process of embedding data into a multimedia cover, and can be used primarily for copyright protection and other purposes. Schemes that have recently been proposed modify the pixel values or Transform domain coefficients. The Singular Value Decomposition (SVD) is a practical numerical tool with applications in a number of signal processing fields including image compression. In an SVD-based watermarking scheme, the singular values of the cover image are modified to embed the watermark data. This method has been proposed an optimal SVD-based watermarking scheme that embeds the watermark in two steps. In the first step, the cover image is divided into smaller blocks and a piece of the watermark is embedded in each block. In the second step extracting the watermark from the watermarked image. Use of SVD provides robustness. It can be proved by testing it in presence of various noise attacks & general image processing operations.