A Semi-fragile Digital Watermarking Technique Based on Wavelet Transform for Image Authentication

摘要

A new semi-fragile digital watermarking technique for image authentication is proposed in the paper. In the proposed scheme, we embed watermarks in the discrete wavelet domain of the image by quantizing the corresponding coefficients. Unlike previously proposed techniques, this novel approach provides information on specific frequencies as well as spatial regions of the image that have been modified, which makes tamper detection possible. This allows the user to make application-dependent decisions concerning whether an image, which is lossy compressed for instance, still has credibility. Simulation results indicate the advantages of the proposed techniques.