A Novel Digital Watermark Based on Wavelet Coefficients Comparison

Watermark technology is one of the most promising and effective ways for copyright protection of digital media and safe transmission of digital information. In the proposed method, the watermark is embedded in the components of medium frequency on the horizontal and vertical direction based on the wavelet coefficients comparison, and an effective strategy of parameter adjustment is used to reduce the error occurred in the traditional method. Then the attack testes are completed in the environment of MATLAB 7.0. The results indicate that the presented method performs good robustness in addition to holding the image quality under the noise attack, filtering and image cutting etc..