Method and apparatus of managing visual content
A method of managing visual content. In one instance, the method includes receiving a stream of video fingerprints, derived in a fingerprint generator by an irreversible data reduction process, from respective temporal regions within a particular visual content stream and at a fingerprint processor that is physically separate from the fingerprint generator via a communication network. The fingerprints are processed in the fingerprint processor to generate metadata which is not directly encoded in the fingerprints. Processing of the fingerprints includes windowing the stream of fingerprints with a time window, deriving frequencies of occurrence of particular fingerprint values or ranges of fingerprint values within each time window, determining statistical moments or entropy values of said frequencies of occurrence, comparing said statistical moments or entropy values with expected values for particular types of content, and generating metadata representing the type of the visual content.
1. A method of managing visual content, comprising the steps of:
receiving a stream of video fingerprints, derived in a fingerprint generator by an irreversible data reduction process from respective temporal regions within a particular visual content stream, at a fingerprint processor that is physically separate from the fingerprint generator via a communication network; and
processing said fingerprints in the fingerprint processor to generate metadata which is not directly encoded in the fingerprints; wherein said processing includes:
windowing the stream of video fingerprints with a time window,
deriving frequencies of occurrence of particular fingerprint values or ranges of fingerprint values within each time window by converting each set of particular fingerprint values to a histogram,
determining statistical moments or entropy values of said frequencies of occurrence,
comparing said statistical moments or entropy values with expected values for particular types of content,
generating metadata representing the type of the visual content, and
providing the metadata to a control system for managing video content distribution.
2. The method according to claim 1 , wherein said statistical moment comprises one or more of the mean; variance; skew or kurtosis of said frequencies of occurrence.
3. The method according to claim 1 , wherein said communication network comprises the Internet.
4. The method according to claim 1 , wherein a video fingerprint stream has less than 500 bytes of data per field.
5. The method according to claim 1 , wherein a video fingerprint stream has less than 200 bytes of data per field.
6. The method according to claim 1 , wherein said content comprises a video stream of video frames and wherein a fingerprint is generated for substantially every frame in the video stream.
7. An apparatus for use in managing visual content, the apparatus comprising:
a fingerprint processor configured to receive via a communication network a stream of video fingerprints derived in a fingerprint generator that is physically separate from the fingerprint processor by an irreversible data reduction process from respective temporal regions within a particular visual content stream, the fingerprint processor including
a window unit configured to receive said stream of video fingerprints and apply a time window,
a frequency of occurrence histogram unit configured to derive the frequencies of occurrence of particular fingerprint values in each time window by converting each set of particular fingerprint values to a histogram,
a statistical moment unit configured to derive statistical moments of said frequencies of occurrence, and
a classifier configured to generate from said statistical moments metadata representing the type of the visual content to provide the metadata to a control system for managing video content distribution.
8. The apparatus according to claim 7 , further comprising an entropy unit configured to derive entropy values for histograms of frequencies of occurrence and wherein said classifier is configured to generate said metadata representing the type of the visual content additionally from said entropy values.
9. A non-transitory computer readable medium comprising a computer program which causes programmable apparatus to implement a method of managing visual content, comprising the steps of:
receiving a stream of video fingerprints, derived in a fingerprint generator by an irreversible data reduction process from respective temporal regions within a particular visual content stream, at a fingerprint processor that is physically separate from the fingerprint generator via a communication network; and
processing said fingerprints in the fingerprint processor to generate metadata which is not directly encoded in the fingerprints; wherein said processing includes:
windowing the stream of video fingerprints with a time window,
deriving frequencies of occurrence of particular fingerprint values or ranges of fingerprint values within each time window by converting each set of particular fingerprint values to a histogram,
determining statistical moments or entropy values of said frequencies of occurrence,
comparing said statistical moments or entropy values with expected values for particular types of content,
generating metadata representing the type of the visual content, and
providing the metadata to a control system for managing video content distribution.