Local expert forest of score fusion for video event classification

Jingchen Liu, Scott McCloskey, Yanxi Liu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Scopus citations


We address the problem of complicated event categorization from a large dataset of videos "in the wild", where multiple classifiers are applied independently to evaluate each video with a 'likelihood' score. The core contribution of this paper is a local expert forest model for meta-level score fusion for event detection under heavily imbalanced class distributions. Our motivation is to adapt to performance variations of the classifiers in different regions of the score space, using a divide-and-conquer technique. We propose a novel method to partition the likelihood-space, being sensitive to local label distributions in imbalanced data, and train a pair of locally optimized experts each time. Multiple pairs of experts based on different partitions ('trees') form a 'forest', balancing local adaptivity and over-fitting of the model. As a result, our model disregards classifiers in regions of the score space where their performance is bad, achieving both local source selection and fusion. We experiment with the TRECVID Multimedia Event Detection (MED) dataset, detecting 15 complicated events from around 34k video clips comprising more than 1000 hours, and demonstrate superior performance compared to other score-level fusion methods.

Original languageEnglish (US)
Title of host publicationComputer Vision, ECCV 2012 - 12th European Conference on Computer Vision, Proceedings
Number of pages14
EditionPART 5
StatePublished - 2012
Event12th European Conference on Computer Vision, ECCV 2012 - Florence, Italy
Duration: Oct 7 2012Oct 13 2012

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
NumberPART 5
Volume7576 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other12th European Conference on Computer Vision, ECCV 2012

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


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