Video fingerprint

Video fingerprinting is a technique in which software identifies, extracts, and then summarizes characteristic components of a video recording, enabling that video to be uniquely identified by its resultant "fingerprint". This technology has proven to be effective at identifying and comparing digital video data.

Video fingerprinting should not be confused with digital watermarking, which relies on inserting identifying features into the content, and therefore changing the content. Some watermarks can be inserted in a way that they are imperceptible by a viewer. A robust watermark can be difficult to detect and remove, but removal of invisible watermarks is a significant weakness.

Since watermarks must be inserted into the video, they only identify copies of the particular video made after that point in time. For example, if a watermark is inserted at broadcast it cannot be used to identify copies of the video made before the broadcast.

Video fingerprinting does not rely on any addition to the video stream. A video fingerprint cannot be "removed", because it is not "added". In addition, a reference video fingerprint can be created at any point, from any copy of the video.

Watermarks offer some advantages over fingerprinting. A unique watermark can be added to the content at any stage in the distribution process, and multiple independent watermarks can be inserted into the same video content. This can be particularly useful in tracing the history of a copy of a video. Detecting watermarks in a video can indicate the source of an unauthorized copy.

While video fingerprinting systems must search a potentially large database of reference fingerprints, a watermark detection system only has to do the computation to detect the watermark. This computation can be significant, and when multiple watermark keys must be tested, then watermarking can fail to scale to the volumes required by commercial applications such as user generated video services.

Video fingerprinting is of interest in the Rights Management (DRM) area, particularly regarding the distribution of unauthorized content on the Internet. Video fingerprinting systems enable content providers (e.g., film studios) or publishers (e.g., user generated content (UGC) sites) to determine if any of the publisher's files contain content registered with the fingerprint service. If registered content is detected, the publisher can take the appropriate action – remove it from the site, monetize it, add correct attribution, etc.

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Wikipedia