A FAST AND ROBUST HYBRID WATERMARKING SCHEME BASED ON SCHUR

This paper presents a robust watermarking for still digital images based on schur factorization and Singular Value Decomposition (SVD). In this paper, image is decomposed into 88  blocks and after applying schur factorization, the stable largest eigen values of the upper triangle is used as robust locations for embedding watermark. The matrix array formed by largest eigen values further factorized by Singular Value Decomposition and singular values of these coefficients are modified with the singular values of watermark. Later inverse SVD and inverse schur is applied to get watermarked image. The watermark is subjected to checkmark watermarking evaluation software and it is found that the method is robust against number of attacks and highly imperceptible.