Granted Patent B2

US 7,796,780 · App. 11/165,435 · Granted Sep 14, 2010

Abstract

Claims (52)

1. A non-transitory computer-readable medium comprising software for video processing, which when executed by a computer system, cause the computer system to perform operations comprising a method of:

receiving video from an overhead view of a scene;

detecting moving pixels in the video;

detecting line segments in a foreground of the scene in the video based on detected moving pixels;

identifying targets in the video based on the detected line segments;

tracking targets in the video based on the identified targets; and

managing tracked targets in the video, wherein detecting line segments comprises:

counting edge pixels; and

identifying a line segment based on the edge pixels.

2. A computer-readable medium as in claim 1 , wherein detecting moving pixels comprises:

separating the foreground in the video from background in the video; and

detecting foreground edges in the video.

3. A computer-readable medium as in claim 1 , wherein identifying the line segment comprises:

identifying a start point;

predicting next search directions;

identifying a next line pixel; and

providing a line segment.

4. A computer-readable medium as in claim 1 , wherein identifying targets comprises:

updating existing targets;

detecting new targets;

refining the new targets;

merging the existing targets and the new targets;

splitting the existing targets and the new targets; and

cleaning the existing targets and the new targets.

5. A computer-readable medium as in claim 4 , wherein updating targets comprises:

predicting a target on its new location;

assigning detected line segments to the predicted target; and

updating the target.

6. A computer-readable medium as in claim 4 , wherein detecting new targets comprises:

performing line segment clustering;

performing cluster verification based on the line segment clustering; and

generating a new target based on the cluster verification.

7. A computer-readable medium as in claim 4 , wherein refining the new targets comprises:

agglomerating remaining line segments to nearest targets;

re-estimating the targets; and

updating the targets.

8. A computer-readable medium as in claim 4 , wherein merging the existing targets and the new targets comprises:

obtaining a target pair; and

merging the target pair if parameters of the target pair are similar.

9. A computer-readable medium as in claim 4 , wherein splitting the existing targets and the new targets comprises:

obtaining a target;

performing line clustering on the obtained target if the obtained target is not similar to a normal target to obtain clusters; and

assigning a target identities to the clusters if the clusters are similar to the normal target.

10. A computer-readable medium as in claim 4 , wherein merging and splitting the existing targets and the new targets comprises:

generating a foreground mask;

detecting foreground objects based on the foreground mask; and

analyzing the foreground objects to obtain a number of targets.

11. A computer-readable medium as in claim 10 , wherein analyzing the foreground objects is based on comparing the foreground objects to a multiple target size threshold, a minimum single target size threshold, and a maximum single target size threshold.

12. A computer-readable medium as in claim 4 , wherein cleaning the existing targets and the new targets comprises:

obtaining a target;

maintaining the obtained target if the obtained target is detected in a current frame or was not moving out of a field of view of the video camera; and

removing the obtained target if the obtained target is not detected in a current frame and was moving out of a field of view of the video camera.

Assignments (8)