blind image
5.This paper applies an algorithm of blind image watermarking in DCT domain based on module 2 add operation through a method of introducing random and adjusting AC coefficient of matrix,Experiments show that this algorithm can effectively prevent information lose of watermarking from damaging and it is robust against cut and alternation.
9.4. We put forward an algorithm for semi-fragile watermarking of still image according to the invariant property to JPEG lossy compression and based on the invariant property to JPEG of the coefficient of DCT, which enables the real blind examination and provides good guarantee for the safety of the system to the control of the key at the same time;

