Research and DSP Realization of Digital Watermarking Algorithm Used for Copyright Protection

With the development of communication technology, digital watermarking is widely used in copyright protection and the algorithms are more and more sophisticated. A new digital watermarking algorithm used for copyright protection is proposed in this paper, and it is realized by DSP. First, the original image is blocked, and the integer lifting wavelet transform is carried out for each blocked image; then the direct sequence spread spectrum is done to the watermark sequence by using the spreading codes which are generated through the chaotic system, and the spread spectrum watermark is embedded in the high-frequency sub-bands; Finally, the watermarked image is obtained through the block inverse wavelet transform. Watermark detection process does not require the original image; it is a blind detection algorithm. The algorithm can resist to random noise, filtering, compression, shearing, sample and other attacks. The DSP realization can better process the watermark embedding and detection, and can meet the requirements of general application. It has the features such as high computing speed, high algorithm efficiency and strong practicality and so on.