6Van Schyndel R G,Tirkel A Z,Osborne C F.A digital watermark.Proc.IEEE Int.Conf.on Image Processing,1994:86-89.
7Wolfgang R B,Delp E J.Overview of image security techniques with applications in multimedia system.Proceeding of the SPIE Conference on Multimedia Networks:Security,Displays,Terminals and Gateways,1997,3228 (7):297-308.
8Pitas I.A method for signature casting on digital images.Proceedings of IEEE International Conference on Image Processing,1996,3 (5):215-218.
9Brassil J,Low S,Maxemchuk N,et al.Electronic marking and identification techniques to discourage document copying.IEEE J.Select.Areas Common.,1995,13(52):1495-1504.
10Kite T D,Venkata N D,Evans B L.A fast high-quality inverse halftoning algorithm for error diffused halftones.IEEE Transactions on Image Processing,2000,9(9):1583-1592.
