基于混沌和脆弱水印的图像篡改检测算法

Image tamper detection scheme based on chaotic system and fragile watermarking

针对现有基于脆弱水印方法的不足,提出了一种新的结合混沌系统和脆弱水印的图像篡改检测算法。算法首先利用Arnold cat映射对原始图像进行k次置乱,然后选取置乱图像的最低有效位(LSB)平面作为水印嵌入位置,实际嵌入的水印由Logistic混沌映射产生的随机二进制序列与原始水印异或得到,通过LSB替换算法嵌入。最后对LSB替换后图像进行T-k次的Arnold cat映射得到水印图像。实验结果表明,混沌系统的引入大大增强了脆弱水印的安全性;另外,针对不同种类的攻击,算法具有良好的篡改检测和定位精确性。

In order to solve the shortage of the method based on fragile watermarking, a new chaotic system and fragile watermarking based image tamper detection algorithm was proposed. Firstly, the method used Arnold cat map k times to scramble the original image, and then chose the Least Significant Bit （LSB） plane of the scrambled image as the embedding position. The actual watermark information was formed by using exclusive-or operation between a random binary sequence produced by Logistic map and the original watermark, and the LSB replacement method was utilized to embed watermark. Finally, the watermarked image was obtained by utilizing Arnold cat map T - k times. The experimental results show that, the introduction of chaotic system to a great extend improves the security of the proposed scheme. In addition, the proposed method achieves superior tamper detection and localization accuracy under different common attacks.