Abstract：In order to effectively protect the copyright of multimedia data

a novel digital color image watermarking algorithm based on singular value decomposition was presented in this paper. The watermark used in the algorithm is 8bits gray-level image which is used extensively in these days and includes more information than the binary image watermark. The scheme first encodes the gray-level watermark into the binary-value bit sequence using the singular value decomposition

and then embeds the encoded watermark into the region with high visual masking effect. In order to access the aim of the watermark’s imperceptions

a method which extracts the blue channel in RGB color space of the host image is adopted. The application of watermark encoding scheme makes our method achieve the goal of watermark blind-extraction and large quantity of vivid information’s hiding. Simulation results show that the proposed method is more robust than traditional methods. The watermarks extracted from the host image after different kinds of attacks that usually encountered in the course of image processing and transmission are still clear and their visual information are nearly lossless.