Improved fragile watermark technique
LI Tao, MENG Qing_hai,XU Tong(91550 Unit of PLA, Dalian 116023, China)
This paper firstly introduces the principle of watermark and summarizes the techniques of image watermark. Then an improved fragile watermark technique is presented, where Haar wavelet transform does not involve normalization, and quantization function is mended, watermark embedding equation is also improved. With these improvements, the watermark technique does work precisely. Using the error control code, fragile watermark detection can be done without original watermark.