The Blind Watermarking Method Simulation Research Based on Wavelet Tree Quantization

Abstract

This article studies image copyright protection algorithm based on watermark. Aimed at the defect that watermark loading algorithm easily leads to the loss of original image information, it proposes a kind of quantization based on wavelet tree structure so that in the watermark extraction process, it can restore the original intact image without original image or watermark information. First, it makes use of level-four wavelet transform to construct tree wavelet coefficient waveband diagram. Then it discretizes and insets watermark information into different waveband nodes of tree structure according to coefficient variation maximum principle. By designing self-adaption threshold value during extracting process, it can restrict some common watermarking loss better, such as smoothing, mean value filtering and gaussian noise. The experiment result proves that this method can make watermark image the visually same as the original image and watermark can still be extracted effectively after preprocessing.