Mitsubishi Electric Research Laboratories, Inc.

Hiroshi Ito

Huifang Sun

Ajay Divakaran

Tommy C Poon

This invention relates to methods of feature extraction from MPEG-2 and MPEG-4 compressed video sequences. The spatio-temporal compression complexity of video sequences is evaluated for feature extraction by inspecting the compressed bitstream and the complexity is used as a descriptor of the spatio-temporal characteristics of the video sequence. The spatio-temporal compression complexity measure is used as a matching criterion and can also be used for absolute indexing. Feature extraction can be accomplished in conjunction with scene change detection techniques and the combination has reasonable accuracy and the advantage of high simplicity since it is based on entropy decoding of signals in compressed form and does not require computationally expensive inverse Discrete Cosine Transformation (DCT).

Methods of feature extraction of video sequences

This invention relates to methods of abrupt scene change detection and fade detection for indexing of MPEG-2 and MPEG-4 compressed video sequences. Abrupt scene change and fade-detection techniques applied to signals in compressed form have reasonable accuracy and the advantage of high simplicity since they are based on entropy decoding and do not require computationally expensive inverse Discrete Cosine Transformation (DCT).

Methods of scene change detection and fade detection for indexing of video sequences

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.

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Fort Lee, NJ, United States of America

Hiroshi Ito