Object tracking systems and methods are described. In one aspect, a three-dimensional
point cloud is generated from a time series of video frames and partitioned into
a set of vertically-oriented bins. The point cloud is mapped into one or more plan-view
images each containing for each vertically-oriented bin a corresponding pixel having
one or more values computed based upon one or more attributes of the point cloud
members occupying the corresponding vertically-oriented bin. The object is tracked
based at least in part upon one or more of the plan-view images. In another aspect,
one or more original object templates are extracted from at least one of the one
or more plan-view images, and the object is tracked based at least in part upon
a comparison of at least one of the object templates with regions of the corresponding
plan-view images. In another aspect, the point cloud may be discretized along the
vertical axis into two or more horizontal partitions.