They are not equally reliable: semantic event search using differentiated concept classifiers

Xiaojun Chang, Yao-Liang Yu, Yi Yang, Eric P. Xing

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

26 Citations (Scopus)


Complex event detection on unconstrained Internet videos has seen much progress in recent years. However, state-of-the-art performance degrades dramatically when the number of positive training exemplars falls short. Since label acquisition is costly, laborious, and time-consuming, there is a real need to consider the much more challenging semantic event search problem, where no example video is given. In this paper, we present a state-of-the-art event search system without any example videos. Relying on the key observation that events (e.g. dog show) are usually compositions of multiple mid-level concepts (e.g. "dog," "theater," and "dog jumping"), we first train a skip-gram model to measure the relevance of each concept with the event of interest. The relevant concept classifiers then cast votes on the test videos but their reliability, due to lack of labeled training videos, has been largely unaddressed. We propose to combine the concept classifiers based on a principled estimate of their accuracy on the unlabeled test videos. A novel warping technique is proposed to improve the performance and an efficient highly-scalable algorithm is provided to quickly solve the resulting optimization. We conduct extensive experiments on the latest TRECVID MEDTest 2014, MEDTest 2013 and CCV datasets, and achieve state-of-the-art performances.

Original languageEnglish
Title of host publicationProceedings - 29th IEEE Conference on Computer Vision and Pattern Recognition - CVPR 2016
Subtitle of host publication26 June – 1 July 2016 Las Vegas, Nevada
EditorsLourdes Agapito, Tamara Berg, Jana Kosecka, Lihi Zelnik-Manor
Place of PublicationPiscataway NJ USA
PublisherIEEE, Institute of Electrical and Electronics Engineers
Number of pages10
ISBN (Electronic)9781467388511
ISBN (Print)9781467388528
Publication statusPublished - 2016
Externally publishedYes
EventIEEE Conference on Computer Vision and Pattern Recognition 2016 - Las Vegas, United States of America
Duration: 27 Jun 201630 Jun 2016 (Proceedings)


ConferenceIEEE Conference on Computer Vision and Pattern Recognition 2016
Abbreviated titleCVPR 2016
Country/TerritoryUnited States of America
CityLas Vegas
Internet address

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