Sıfır atamalı süzgeç kümeleri ile dalgalama

A watermarking scheme for audio and image files is proposed based on waveletdecomposition via zero assigned filter banks. Zero assigned filter banks are per-fect reconstruction, conjugate quadrature mirror filter banks with assigned zerosin low pass and high pass filters. They correspond to a generalization of filterbanks that yield Daubechies wavelets.The watermarking method consists of partitioning a given time or space sig-nal into frames of fixed size, wavelet decomposing each frame via one of two filterbanks with different assigned zeros, compressing a suitable set of coefficients inthe wavelet decomposition, and reconstructing the signal from the compressedcoefficients of frames. In effect, this method encodes the bit `0? or `1? in eachframe depending on the filter bank that is used in the wavelet decomposition ofthat frame.The method is shown to be perceptually transparent and robust against channelnoise as well as against various attacks to remove the watermark such as denois-ing, estimation, and compression. Moreover, the original signal is not neededfor detection and the bandwidth requirement of the multiple authentication keysthat are used in this method is very modest.Keywords: Wavelets, filter banks, zero assignment, watermarking.