A watermarking algorithm based on wavelet tree

An un-blind watermarking algorithm based on discrete wavelet transform is brought forward in this article. This algorithm inherits the thought of embedded zerotree wavelet (EZM). First, use db1 wavelet to make the image three levels decomposition, find out the wavelet tree of significant coefficients of low frequency and middle frequency and then embed watermarking used additive formula with these coefficients. Watermarking information is a black and white two-value image, the identification of intensity of embedded watermarking can use tensile factors, original image needed as watermarking detected. Experimental Results showed that it can ensure robustness of watermarking when embedded a part of watermarking information in low frequency significant coefficients and some in middle frequency.