Methods of scene fade detection for indexing of video sequences

• US 6,327,390 B1
• Filed: 01/14/1999
• Issued: 12/04/2001
• Est. Priority Date: 01/14/1999
• Status: Expired due to Term

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Sun, Huifang, Ito, Hiroshi, Divakaran, Ajay, Poon, Tommy C.
• Primary Examiner(s): Chen, Wenpeng
• Application Number:
  US09/231,699
• Time in Patent Office: 1,055 Days
• Field of Search: 382/236, 382/235, 382/232, 382/239, 348/700, 348/699, 375/240.25, 375/240.26, 345/328, 345/327, 345/326
• US Class Current: 382/235
• CPC Class Codes: H04N 19/142 Detection of scene cut or scene change
• CPC Class Codes: H04N 19/179 the unit being a scene or a shot
• CPC Class Codes: H04N 19/87 involving scene cut or scene change detection in combination with video compression
• CPC Class Codes: H04N 5/147 Scene change detection

Abstract

A method locates scene changes in a sequence of images or frames that have been compressed without first decompressing the sequence. The sequence includes subsequences of P-frames between I-frames. DC residual coefficients including sign information are extracted from the sub-sequences of P-frames. If the number of residual coefficients in the P-frames exceed a predetermined threshold, then a scene change is indicated. Positive coefficients indicate fade-ins, and negative coefficients indicate fade-outs.

Claims

1. A method of processing digital image-representative video data in compressed form comprising the steps of:

extracting, from a sequence of digital image-representative video data in compressed form, which comprises at least I-frames and P-frames occurring between the I-frames, each sub-sequence of P-frames corresponding to a group of pictures,

processing said video data in compressed form for each frame in said sub-sequence to extract corresponding DC residual coefficients, including sign information, for each of said Pframes, and

determining numbers of positive and negative DC residual coefficients in said extracted P-frames in excess of a threshold value to locate fade-in and fade-out scene changes, respectively.

2. A method of processing digital image-representative video

data in compressed form according to claim 1 wherein:

said step of determining comprises counting the number of blocks having positive DC components and the number of blocks having negative DC components in each said P-frame,

determining which count is greater and saving the sign of the greater for each said P-frame,

identifying each P-frame where the greater count is equal to or more than a predetermined majority of non-zero DC components in said P-frame,

identifying each group of pictures in which DC components of a particular sign consistently exceed those of opposite sign,

designating a fade-in scene change where said greater count in each said identified group of pictures is associated with a positive sign, and

designating a fade-out scene change where said greater count in each said identified group of pictures is associated with a negative sign.

3. A method of processing digital image-representative video data in compressed form according to claim 2 wherein:

said step of identifying each P-frame further comprises identifying each P-frame where the greater count is equal to or more than 60 percent of the non-zero DC components in said frame.

4. The method of claim 2 wherein:

said step of identifying each group of pictures comprises identifying each such group of pictures in which DC components of one sign exceed those of opposite sign in all P-frames corresponding to a time interval substantially equal to a fade sequence.

5. The method of claim 3 wherein:

said step of identifying each group of pictures comprises identifying each such group of pictures in which DC components of one sign exceed those of opposite sign in all P-frames during a time interval of the order of one second.

6. The method of claim 1 wherein:

said step of determining numbers of positive and negative DC residual coefficients in said extracted P-frames in excess of a threshold value comprises identifying each group of pictures in which DC components of one sign exceed the number of DC components of the opposite sign by at least a predetermined value.