| 摘要 |
PURPOSE: A method for embedding and detecting a watermark is provided to supply a robust watermark against various attacks for image data. CONSTITUTION: According to image compression technology, an encoded bitstream is obtained through the compression of an original image(S610), and entire DCT(Discrete Cosine Transform) for the bit stream is performed(S620). A watermark is inserted through the increase and decrease of DCT coefficients according to the time sequence for plural frames(S630). Received compressed image data are decoded, and the entire DCT for the decoded image data is performed. According to the increase or decrease of DCT coefficient average within a low frequency domain per WGP(Watermarking Group of Pictures) in the DCT region, the watermark is detected. |
