Video copy detection

The goal of this process is to protect a video creator's intellectual property.

Oostveen et al. introduced the concept of a fingerprint, or hash function, that creates a unique signature of the video based on its contents.

This fingerprint is based on the length of the video and the brightness, as determined by splitting it into a grid.

B.Coskun et al. presented two robust algorithms based on discrete cosine transform.

Hampapur and Balle created an algorithm creating a global description of a piece of video based on the video's motion, color, space,[clarification needed] and length.

To look at the color levels of the image was thought, and for this reason, Li et al. created an algorithm that examines the colors of a clip by creating a binary signature get from the histogram of every frame.

[clarification needed] This algorithm, however, returns inconsistent results in cases in which a logo is added to the video, because the insertion of the logo's color elements adds false information that can confuse the system.

Watermarks are used to introduce an invisible signal into a video to ease the detection of illegal copies.

In such a case (e.g., two distinct news broadcasts), the algorithm can return that the video in question is a copy as the news broadcast often involve similar kind of banner and presenter often sit in a similar position.

Videos with very minimal changes in frames with respect to time are more vulnerable to hash collision.

In this algorithm, the video is divided in N blocks, sorted by gray level.

It generates a signature of a whole video, and can easily handle changes in format or added watermarks, but is less tolerant of cropping or clipping.

[3] Described by A. Joly et al., this algorithm is an improvement of Harris' Interest Points detector.

In every image, the algorithms identifies and defines two parts: the background, a set of static elements along a temporal sequence, and the motion, persistent points changing positions throughout the video.

[clarification needed] There exist algorithms for video copy detection that are in use today.