Watermarking Schemes For Copy Protection : A Survey

DIGITAL WATERMARKING IS THE PROCESS OF EMBEDDING INFORMATION INTO A DIGITAL SIGNAL, I.E. AUDIO,PICTURES, VIDEO, ETC. EMBEDDED MARKS IN THE MESSAGE ARE GENERALLY IMPERCEPTIBLE BUT CAN BE DETECTED OR EXTRACTED. THE EMBEDDING TAKES PLACE BY MANIPULATING THE CONTENT OF THE DIGITAL DATA, WHICH MEANS THE INFORMATION IS NOT EMBEDDED IN THE FRAME AROUND THE DATA. IF THE SIGNAL IS COPIED, THEN THE EMBEDDED INFORMATION IS ALSO IN THE COPY. BY IMPERCEPTIBLY HIDING INFORMATION INTO THE VIDEO CONTENT IT WILL BE POSSIBLE TO PREVENT COPYING OR PLAYBACK OF SUCH CONTENT. SO,WATERMARKING IS AN EMERGING TECHNOLOGY THAT IS CLAIMED TO HAVE AN IMPORTANT APPLICATION IN COPY PROTECTION. A VARIETY OF WATERMARKING TECHNIQUES HAVE BEEN PROPOSED BY RESEARCHERS FOR THE COPY-PROTECTION. THIS PAPER PRESENTS AN EXTENSIVE REVIEW OF THE PREVAILING LITERATURE IN WATERMARKING FOR COPY PROTECTION.