A Novel Blind Robust Watermarking Scheme Based on Statistic Characteristic of Wavelet Domain Coefficients

In this paper, a novel blind watermarking scheme for still image based on the two-dimensional discrete wavelet transform (DWT) is proposed. In the scheme, digital watermarking with a pseudo-random sequence is derived from a full logistic map system, and the robustness is achieved by embedding every bit of watermark sequence several times in many different locations in approximate sub-band of one-level Haar wavelet decomposition. The strength of watermarking is adjusted by an auto-adaptive way for fidelity constraints. During detection process, by use of the statistic characteristic of sub-band LL coefficients and the maximum subjection principle, the watermarking is extracted reliably without recurring to original image. Simulations demonstrate that the proposed method can resist many kinds of signal processing attacks such that JPEG compression, additive noise, linear filtering, format conversion, cropping and slight geometric distortion, and so the proposed algorithm has high robustness.