Action Recognition in Temporally Untrimmed Videos!

Automatically recognizing and localizing a large number of action categories from videos in the wild of significant importance for video understanding and multimedia event detection. THUMOS workshop and challenge aims at exploring new challenges and approaches for large-scale action recognition with large number of classes from open source videos in a realistic setting.

Most of the existing action recognition datasets are composed of videos that have been manually trimmed to bound the action of interest. This has been identified to be a considerable limitation as it poorly matches how action recognition is applied in practical settings. Therefore, THUMOS 2015 will conduct the challenge on temporally untrimmed videos. The participants may train their methods using trimmed clips but will be required to test their systems on untrimmed data.

A new forward-looking dataset containing over 430 hours of video data and 45 million frames (70% larger than THUMOS'14) with the following components is made available under this challenge:

  • Training Set: over 13,000 temporally trimmed videos from 101 action classes.
  • Validation Set: Over 2100 temporally untrimmed videos with temporal annotations of actions.
  • Background Set: Approximately 3000 relevant videos guaranteed to not include any instance of the 101 actions.
  • Test Set: Over 5600 temporally untrimmed videos with withheld ground truth.

All videos are collected from YouTube. We will evaluate the success of the proposed methods based on their performance on the new THUMOS 2015 Dataset in two tasks:

  1. Action Classification: this task accepts submissions for whole-clip action classification on 101 action classes.
  2. Temporal Action Localization: this task accepts submissions on action recognition and temporal localization on a subset of 20 action classes.

Participants may either submit a notebook paper that briefly describes their system, or a research paper detailing their approach. All of the submission results will be summarized during the workshop and included in the workshop\conference proceedings. Additionally, the top performers will be invited to give oral presentations, with remaining entries encouraged to present their work in the poster session.

For more details, please see the Evaluation Setup document or the released resources.

See the last THUMOS Challenges: THUMOS 2014 and THUMOS 2013
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[06/22/2015] The summary presentations and notebook papers were uploaded.

[06/14/2015] The results for the challenge were released on the website.

[05/07/2015] The deadline has been extended to May 30, 2015 [11:59 PST].

[05/04/2015] Evaluation document and sample submission files were updated.

[05/01/2015] This year's test set is now available.

[05/01/2015] Due to their extreme large size, we will not be releasing low-level features this year. Participants are encouraged to develop and test new features for the challenge.

[04/10/2015] The development kit with sample submission files and is now available.

[04/10/2015] The first part of the training data (videos+annotations for background and validation) was released.

[3/2015] Website launched.

Mailing List

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Important Dates

  • Test Data Release: May 1, 2015
  • Submission Deadline: May 30, 2015
  • Notebook Papers Due: June 3, 2015
  • Publication date: As per conference schedule
  • Workshop / Results Announcement: June 11, 2015

Program Chairs

General Chairs