US 6,295,367 B1 · System and method for tracking movement of objects in a scene using correspondence graphs

Abstract

A system and method for tracking movement of objects in a scene from a stream of video frames using first and second correspondence graphs. A first correspondence graph, called an object correspondence graph, is formed comprising a plurality of nodes representing region clusterss in the scene which are hypotheses of objects to be tracked, and a plurality of tracks. Each track comprises an ordered sequence of nodes in consecutive video frames that represents a track segment of an object through the scene. A second correspondence graph, called a track correspondence graph, is created, comprising a plurality of nodes, each node corresponding to at least one track in the first correspondence graph. A track comprising an ordered sequence of nodes in the second correspondence graph represents the path of an object through the scene. Tracking information for objects, such as persons, in the scene, is accumulated based on the first correspondence graph and second correspondence graph.

Claims38

Dependent claims

A method for tracking movement of objects in a scene from a stream of video frames comprising image information for the scene, the objects represented by region clusters which are hypotheses of objects to be tracked, comprising steps of:

(a) forming a first correspondence graph comprising a plurality of object nodes representing the region clusters, and a plurality of tracks, each track comprising an ordered sequence of object nodes in consecutive video frames that represents a candidate track segment of an object in the scene, wherein the first correspondence graph includes multiple tracks representing multiple candidate track segments for the same object;
(b) forming a second correspondence graph from tracks in the first correspondence graph, the second correspondence graph comprising a plurality of nodes and a plurality of tracks, each node in the second correspondence graph representing at least one track in the first correspondence graph, each track in the second correspondence graph comprising an ordered sequence of nodes representing a path of an object through the scene;
and
(c) accumulating track information for objects based on information in the second correspondence graph.

1 more element

A system for tracking movement of objects in a scene, comprising:

(a) a video camera for monitoring the scene;
(b) frame grabber means coupled to the video camera for generating a stream of video frames representing image information in the scene;
(c) processor means coupled to the frame grabber means, the processor means being programmed to:
(1) form a first correspondence graph comprising a plurality of object nodes representing region clusters which are hypotheses of objects to be tracked, and a plurality of tracks, each track comprising an ordered sequence of object nodes in consecutive video frames that represents a candidate track segment of an object in the scene, wherein the first correspondence graph includes multiple tracks representing multiple candidate track segments for the same object;
(2) form a second correspondence graph from tracks in the first correspondence graph, the second correspondence graph comprising a plurality of nodes and a plurality of tracks, each node in the second correspondence graph representing at least one track in the first correspondence graph, each track in the second correspondence graph comprising an ordered sequence of nodes in the second correspondence graph representing a track of an object through the scene;
and
(3) accumulate track information for objects based on information in the second correspondence graph.

4 more elements

Dependencies are inferred from the claim text.

System and method for tracking movement of objects in a scene using correspondence graphs

Life of this patent

System and method for tracking movement of objects in a scene using correspondence graphs

Life of this patent

Abstract

Claims38