A CONTENT BASED WATERMARKING SCHEME USING RADIAL SYMMETRY TRANSFORM AND SINGULAR VALUE DECOMPOSITION

The Watermarking techniques represent actually a very important issue in digital multimedia content distribution. To protect digital multimedia content we embed an invisible watermark into images which facilitate the detection of different manipulations, duplication, illegitimate distributions of these images. In this paper we present an approach to embedding invisible watermarks into color images using a robust transform of images that is the Radial symmetry transform. The watermark is inserted in blocs of eight pixels large of the blue channel using the Singular Value Decomposition (SVD) of these blocs and those of the radial symmetry transform. The insertion in the blue channel is justified when we know that many works states that the human visual system is less sensible to perturbation in the blue channel of the image. Results obtained after tests show that the imperceptibility of the watermark using this approach is good and its robustness face to different attacks leads to think that the proposed approach is a very promising one