METHOD FOR BURYING DATA IN IMAGE, AND METHOD FOR EXTRACTING THE DATA

摘要

The object of the invention is to provide a method of embedding data in an image and a method of extracting the data, which methods ensures that an image in which data is embedded at the time of JPEG encoding can be decoded by a standard decoder, that the embedded data can be completely extracted at the time of decoding while an irreversible encoding method is used, and that image degradation due to embedding of data is reduced. The invention is characterized in that, at the time of embedding of data in'an image, an original image is divided into unit blocks having 8 × 8 pixels, DCT is performed on the entire frame on a block-by-block basis, each block is quantized according to a quantization table, and one bit of data is substituted for a coefficient value after quantization to embed the data, and in that run-length encoding and Huffman encoding are performed in order, and the value in the quantization table corresponding to the substituted coefficient value after the quantization is replaced with 1.