Implementation of digital watermarking system

It is easy to make perfect unauthorised copies on a large scale in the music, film, book and software publishing industries. A digital watermark - a hidden copyright message with hidden serial numbers-can be used as a direct method of preventing unauthorised copying. This paper presents a novel digital watermarking system based on vector quantisation (VQ) and discrete cosine transform (DCT), which can embed a grey level image. The proposed new system can embed 16 times more information than other traditional DCT based watermarking system. The recovered images have high peak signal to noise ratio (PSNR) value and good visual quality. This system is robust in terms of both JPEG compression and other signal processing attacks.