Scalable Semi-Automatic Annotation for Multi-Camera Person Tracking

• Published in: IEEE transactions on image processing Vol. 25; no. 5; p. 2259
• Main Authors: Nino, Jorge, Frias-Velazquez, Andres, Bo Bo, Nyan, Slembrouck, Maarten, Guan, Junzhi, Debard, Glen, Vanrumste, Bart, Tuytelaars, Tinne, Philips, Wilfried
• Format: Journal Article
• Language: English
• Published: United States 01.05.2016
• ISSN: 1941-0042

This paper proposes a generic methodology for semi-automatic generation of reliable position annotations for evaluating multi-camera people-trackers on large video datasets. Most of the annotation data is computed automatically, by estimating a consensus tracking result from multiple existing trackers and people detectors and classifying it as either reliable or not. A small subset of the data, composed of tracks with insufficient reliability is verified by a human using a simple binary decision task, a process faster than marking the correct person position. The proposed framework is generic and can handle additional trackers. We present results on a dataset of approximately 6 hours captured by 4 cameras, featuring a person in a holiday flat, performing activities such as walking, cooking, eating, cleaning, and watching TV. When aiming for a tracking accuracy of 60cm, 80% of all video frames are automatically annotated. The annotations for the remaining 20% of the frames were added after human verification of an automatically selected subset of data. This involved about 2.4 hours of manual labour. According to a subsequent comprehensive visual inspection to judge the annotation procedure, we found 99% of the automatically annotated frames to be correct. We provide guidelines on how to apply the proposed methodology to new datasets. We also provide an exploratory study for the multi-target case, applied on existing and new benchmark video sequences.