Analysis of quantization watermarking in the wavelet transform domain

Abstract

Quantization watermarking is a method of embedding hidden copyright information based on dithered quantization. Such a scheme is only practical for watermarking applications, where the original signal is available to the detector as for a fingerprinting purpose. The aim of this paper is to analyze the quantization watermarking in the wavelet transform or equivalently in filter bank domain. We involve the nonlinear effect of dithered quantization in the filter bank analysis using the time-domain formulation of the filter bank. We derive a general and compact form for distortion in the host image due to the encoding and embedding process. The formulation can be simplified and optimized for different filter banks and dither signals. We provide some supporting experiments for the analysis.