基于Slant变换的半脆弱水印算法

Semi-fragile Watermarking Algorithm Based on Slant Transform

为了使算法同时具有较高的定位精度和鲁棒性,提出了一种基于Slant变换的半脆弱性数字水印算法.算法引入"相关块组"的概念,结合Slant变换高能量集中性及直流量化原理完成水印嵌入过程,在认证过程中使用了定位参考块.实验结果表明,该算法能容忍一定程度的JPEG压缩、Gauss噪声等偶然篡改,对图像中发生的篡改可以有效地检测并进行精确地定位.

To keep algorithm＇s high robustness and accuracy, a semi-fragile digital watermarking algorithm based on slant transform was proposed. The algorithm introduced the conception of ＂relevant- block-group＂ , finished the process of watermark embedding by utilizing the characteristic of high energy concentration and the principle of the DC coefficient quantization, and used positioning reference blocks during the process of authentication. Experiment results show that, to some extent, the algorithm tolerates the accidental tampering, such as the JPEG compression, gauss noise, etc. The tampered areas can be detected effectively and located accurately.