A fragile watermarking based on the triplet of wavelet coefficients

A novel fragile watermarking approach based on the triplet of wavelet coefficients is proposed and 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.