Tracking People by Learning Their Appearance

—An open vision problem is to automatically track the articulations of people from a video sequence. This problem is difficult because one needs to determine both the number of people in each frame and estimate their configurations. But, finding people and localizing their limbs is hard because people can move fast and unpredictably, can appear in a variety of poses and clothes, and are often surrounded by limb-like clutter. We develop a completely automatic system that works in two stages; it first builds a model of appearance of each person in a video and then it tracks by detecting those models in each frame (“tracking by model-building and detection”). We develop two algorithms that build models; one bottom-up approach groups together candidate body parts found throughout a sequence. We also describe a top-down approach that automatically builds people-models by detecting convenient key poses within a sequence. We finally show that building a discriminative model of appearanc...

• Type: Journal
• Year: 2007
• Where: PAMI
• Authors: Deva Ramanan, David A. Forsyth, Andrew Zisserman
• Keywords: Bottom-up Approach Groups, PAMI 2007, Video Sequence, —An Open Vision