Browse Prior Art Database

Adaptive Scene Change Detection

IP.com Disclosure Number: IPCOM000117581D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Linzer, EN: AUTHOR

Abstract

Scene change detection is used in Moving Picture Experts Group (MPEG) encoding to place I frames. Scene change detection is often performed by looking at differences in statistics (e.g., average pel value) or at differences between pictures. These methods are often not very robust, and can result in I frames at locations that are not scene changes.

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Adaptive Scene Change Detection

      Scene change detection is used in Moving Picture Experts Group
(MPEG) encoding to place I frames.  Scene change detection is often
performed by looking at differences in statistics (e.g., average pel
value) or at differences between pictures.  These methods are often
not very robust, and can result in I frames at locations that are not
scene changes.

      The I frame placement is done adaptively.  A preliminary scene
change detection is done.  An I frame is placed at a scene change if
and only if another scene change has not recently been detected.

      An example of a preliminary scene change detection is to look
at the difference in average luma and/or chroma values of a reference
frame and the previous reference frame (or the first field of a
reference frame and the last field of the previous reference frame).
If they differ by more than a threshold, a scene change is declared.

      In the Figure, n_mpeg is a constant equal to the number of
fields in a typical Group of Pictures (GOP).  For this Figure,
reference frames are inserted periodically on a non-adaptive basis,
but the type (I or P) of reference frames is determined adaptively.