Digital Watermarking Based on Discrete Cosine Transformation

Watermarking technology is an effective approach to image content authentication and copyright protection, which has got notable achievements in recent years. In different frequency intervals of discrete cosine transformation(DCT), compared the characteristics of the watermarking algorithm, an embedding and detection algorithm was proposed. It can solve the explanation attack well and improve the watermarking security. The theme gives the experiment of the algorithm, and it shows that the algorithm can guarantee the unperceivability and transparency of the digital image. The experimental result analyses that has good robust against JPEG, cropping, and frangibility against the attack of filtering and gauss white noisy. Experiments also showed that the watermark image by extracted, its peak signal to noise ratio (PSNR) values remain in a higher range.