Face segmentation and tracking based on connected operators and partition projection

摘要

A new technique for segmenting and tracking human faces in video sequences is presented. The algorithm relies on the concepts of connected operators and partition projection to tackle the problems of face segmentation and tracking, respectively. It uses a connected operator to extract the connected component that more likely belongs to a face. Such a connected operator is implemented by means of a Binary Partition Tree. A set of connected regions (a node in the tree) is selected maximizing the estimation of the likelihood of being part of a face. This way, a first estimate of the face is obtained. Final face segmentation is carried out by a face extraction step that applies the previous maximization in the partition space. Faces are tracked through the sequence based on the partition projection approach. Partition projection accommodates the partition of the previous image into the information of the current frame. The current image is classified into face, no face and uncertain regions by projecting the previous face partition. Therefore, the projection yields the first estimate of the face. The face core component is grown up to obtain the final face segmentation using the previous face extraction process. The technique has been successfully assessed using several test sequences in raw format (MPEG-4 database) as well as in MPEG-1 format (from the MPEG-7 database).