Hvs-based Image And Video Watermarking Method Study

The　age　of　computer　network　has　brought　great　advantages　in　the　data　acquisition,　exchange　and　transmission,　but　the　transparence　of　digital　data　also　facilitates　unauthorized　copying　and　intentional　tampering.　As　a　potential　and　effective　solution　to　these　problems,　digital　watermarking,　which　embeds　an　imperceptible　signal　(the　watermarking)　into　multimedia　data　such　as　image,　text,　video　and　audio,　has　attracted　considerable　attention　in　the　past　few　years.　This　paper　describe　the　fundamental　demands　and　various　techniques　of　digital　watermarking　and　basic　conception　,　then　presents　three　novel　schemes　of　based　HVS　,　two　for　image　watermarking　and　one　for　video　watermarking.　The　first　scheme　is　proposes　a　blind　image　watermarking　algorithm　based　on　lifting　scheme　wavelet　and　DCT,　The　scheme　combine　the　qualities　of　lifting　scheme　wavelet　and　DCT　and　the　merit　invisibility　of　HVS　,　makes　the　embedded　watermarking　energy　in　the　coefficient　block　have　the　adaptively.　The　algorithm　has　very　strong　robustness　for　some　common　image　processing　operations.　　The　second　scheme　is　proposes　an　iterative　quantization　public　watermarking　scheme　based　on　PSNR.　In　the　watermarking　embedding　procedure,　the　quantization　step　is　adaptively　adjusted　according　to　the　target　PSNR　and　the　characteristics　of　the　HVS,　so　that　a　good　compromise　between　the　imperceptibility　and　robustness　is　reached.　One　watermarking　signal　is　embedded　by　means　of　weight　average　into　a　few　iterative　quantized　low　or　middle　frequency　coefficients.This　manner　provide　the　scheme　has　high　robustness.　　The　third　scheme　is　proposes　a　blind　adaptive　video　watermarking　algorithm　based　on　lifting　scheme　wavelet　and　HVS.　During　the　embedding　process,the　scheme　using　the　merit　of　non-compressed　digital　video　watermarking,and　the　HVS　masking　characteristics　of　texture　area　and　motion　area　are　considered　to　adaptively　adjust　the　embedding　strength　which　can　enhance　the　watermarking　robustness　as　much　as　possible　without　harming　its　invisibility.