用于图像篡改定位和恢复的分层半脆弱数字水印算法-For image tamper localization and recovery in hierarchical semi-fragile digital watermarking algorithm

提出一种基于图像认证的半脆弱数字水印算法。该算法具有较好的自适应性，采用改进的低通滤波器，根据人眼的分辨能力设定 梯度阈值。实验结果证明，该算法对常规图像处理操作具有较强的鲁棒性，能够抵御JPEG顶级有损压缩，同时对于恶意篡改攻击(擦除、扭曲、挤压、光照等操作)表现出脆弱性，可检测出篡改的痕迹和类型。 -A semi-fragile watermark algorithm for image authentication is proposed, which has adaptabilit

基于混沌理论和量化方法实现一种针对灰度图像的鲁棒和脆弱相结合的双重水印算法。-Double watermarking algorithm based on chaos theory and quantitative methods to achieve a combination of robust and fragile phase of the gray-scale image.