Semi-online Multi-people Tracking by Re-identification

Long Lan, Xinchao Wang, Gang Hua, Thomas S. Huang, Dacheng Tao

Research output: Contribution to journalArticlepeer-review


In this paper, we propose a novel semi-online approach to tracking multiple people. In contrast to conventional offline approaches that take the whole image sequence as input, our semi-online approach tracks people in a frame-by-frame manner by exploring the time, space and multi-camera relationship of detection hypotheses in the near future frames. We cast the multi-people tracking task as a re-identification problem, and explicitly account for objects’ appearance changes and longer-term associations. We model our approach using a Multi-Label Markov Random Field, and introduce a fast α-expansion algorithm to solve it efficiently. To our best knowledge, this is the first semi-online approach achieved by re-identification. It yields very promising tracking results especially in challenging cases, such as scenarios of the crowded streets where pedestrians frequently occlude each other, scenes captured with moving cameras where objects may disappear and reappear randomly, and videos under changing illuminations wherein the appearances of objects are influenced.

Original languageEnglish (US)
Pages (from-to)1937-1955
Number of pages19
JournalInternational Journal of Computer Vision
Issue number7
StatePublished - Jul 1 2020
Externally publishedYes


  • Combinatory optimization
  • Deep learning
  • Multi-object tracking
  • Semi-online methods

ASJC Scopus subject areas

  • Software
  • Computer Vision and Pattern Recognition
  • Artificial Intelligence


Dive into the research topics of 'Semi-online Multi-people Tracking by Re-identification'. Together they form a unique fingerprint.

Cite this