基于三重小波系数集的易损水印算法

Novel Fragile Watermarking Based on Triplet of Wavelet Coefficients

提出一种新的基于三重小波系数集的易损水印算法 .定义了三重小波系数集 ,根据将要嵌入的水印比特将三重小波系数集的标准差对阈值的余数量化到不同位置 ,提取时根据该余数所在的不同区间恢复嵌入的水印 .实验结果表明 ,该算法能够反应对图像的篡改 ,指出篡改发生的空间位置并给出篡改的程度 .同时 ,该算法对于一般的图像处理操作如 JPEG压缩和中值滤波等具有一定的鲁棒性 .

A novel fragile watermarking approach based on the triplet of wavelet coefficients is proposed. Triplet of wavelet coefficients is defined.The standard deviation of three wavelet coefficients in the triplet of wavelet coefficients is divided by a prespecified threshold, and watermark bit is embedded by the quantization of the remainder resulted from this division operation.Experimental results show that the proposed algorithm can point out the tamper-existing region and the extent of tampering. And the method is robust to common image processing operations such as JPEG lossy compression and median filtering, etc.