双重认证的变换域图像半脆弱数字水印算法

Dual Authentication Semi-Fragile Watermarking of Images in Transform Domain

提出了一种DCT域与DWT域相结合的双重认证图像半脆弱数字水印算法,定义了一个小波系数量化函数以实现水印的嵌入与提取,根据图像局部特性,该量化函数可动态地进行调整;同时设计了三个混沌密钥,结合DCT域定义水印及其嵌入位置实验表明,该算法在保持对常见的JPEG压缩稳健的同时。

A combination of Discrete Cosine Transform (DCT) and Discrete Wavelet Transform(DWT) domain is introduced and a quantization function is defined to quantify wavelet coefficients according to the watermarks to be embedded. The quantization function can be dynamically adjusted according to the local image characteristics. Three private chaos keys are designed to define the watermarks to be embedded and determine the position for watermarking. Experimental results show that the proposed algorithm is robust against JPEG lossy compression, and provides very good classification of intentional and incidental tampering.