Semi-Fragile Watermarking Based on SVM for Image Authentication

A novel semi-fragile watermarking scheme based on support vector machine (SVM) for image authentication is proposed This scheme first gives a definition of wavelet coefficient direction tree, then the relation model between the root node and its offspring nodes is established using SVM, and further watermark is embedded and extracted based on this relation model. In this scheme, a tempering information matrix and a local tempering appraising function (TAF_L) are defined for image authentication. TAF_L is calculated by a sliding widow and the maximal TAF_L, namely TAF_M, is used to distinguish the acceptable operations from the malicious tempering. In addition, the system has sound robustness to JPEG compression and good secure because not only the watermark is scrambled by a transformation, but also the binding relation among coefficients significantly discourages an adversary from performing the collage attack.