一种复合型自适应盲水印算法

提出同时嵌入鲁棒水印和脆弱水印的复合型自适应盲水印算法。鲁棒水印根据邻居特征平均值和奇偶判决法嵌入到所选择的频带中，再将水印图像分块，把分块图像的灰度均值映射为混沌初值，经过若干次迭代生成脆弱水印，嵌入到其像素灰度值的LSB平面。实验结果表明，该算法对一般的图像处理具有良好的鲁棒性，同时还能对图像篡改进行精确定位，且作为盲水印算法有良好的安全性。

Algorithm of Compound Adaptive Blind Watermark

Embedding robust and fragile watermark in one image simultaneously, an algorithm of compound, adaptive blind watermark is proposed. The robust watermark is embedded in selected sub-band of frequency domain according to neighboring symbol’s mean value and odd-even adjudgement rule. The watermarked image is partitioned into small pieces. Let the grayscale average value of small pieces map the initial values of the chaotic mapping. The fragile watermark obtained by iterating several times of the chaotic mapping is embedded into the LSB plane of the watermarked image. Experimental results show that the method is robust against normal image processing and can precisely detect the location of any changes in images. Being a blind watermark algorithm has good security.