Insertion and detection of hidden watermark in digital image or audio data uses decoded component coefficients that are modulated by signal representing watermarking information to form watermark coefficients

摘要

The watermarking process extracts a sub-set of low frequency components from the data set, and applies entropy decoding to these components. The decoded component coefficients are modulated by a signal representing the watermarking information to form watermark coefficients. These coefficients are entropy encoded then inserted in the place of the initially extracted sub-set of components.