| 摘要 |
Fingerprinting and fingerprint detection, techniques are described which, unlike typical fingerprint systems used to conceal video signals, are compatible with all conceivable forms of signal compression systems while still allowing viewing of the video signal. The fingerprint technique is based on the principle of applying very slight local spatial distortion to the pixels in a video image, and the like, by means of selected warp patterns. Thus the technique provides means for conveying, within the video signal, selected information in the form of the fingerprint which is detectable electronically but which is not noticeable to a critical viewer who is watching the video signal. That is, the resultant fingerprinted video signal will appear to be identical to the undistorted video signal. the fingerprint detection technique provides for the recovery of the conveyed information which may comprise an instruction to prevent the fingerprinted video image from being copied, messages which allow identifying the source and date of an unauthorized copy of the video image, etc.
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