Digital Watermarking for Gray-level Watermarks

Digital watermarking has recently emerged as an important area of research to protect the copyright of multimedia and internet data. Most of other literatures focus on the algorithms of embedding one-dimensional watermarks or twodimensional binary digital watermarks. In this work, a robust method of embedding a gray-level digital watermark into an image is proposed. A gray-level digital watermark is decomposed into a series of binary digital images for implementing multiple watermark. This watermark is self-extractable.