ELECTRONIC WATERMARK DEVICE, AUTHENTICATION PROCESSING DEVICE, DECODING PROCESSING DEVICE, AND RE-QUANTIZATION DEVICE

摘要

There is provided a signature circuit (1) for quantizing an image signal, calculating an authenticator from the quantization index of the image signal, an embedding the authenticator in the quantization index. On the other hand, there is provided an encoder (2) for calculating a difference signal between the image signal and the reference signal, quantizing the difference signal according to the quantization index having the authenticator embedded by the signature circuit (1), and outputting the quantization index of the difference signal.