Digital Image Watermarking using Spread Spectrum Techniques in DCT domain

DCT 영역에서 대역확산에 의한 디지털 영상 워터마킹

In this paper, we propose a digital watermarking method using the spread spectrum techniques in DCT domain. Watermark is embedded in the middle band frequencies of 8$\times$8 DCT block. Therefore, we improve image quality and robustness. Experiment results show that the proposed watermark is robust against various attack.