VIDEO/VISION BASED ACCESS CONTROL METHOD AND SYSTEM FOR PARKING OCCUPANCY DETERMINATION, WHICH IS ROBUST AGAINST ABRUPT CAMERA FIELD OF VIEW CHANGES

• US 20150077549A1
• Filed: 09/16/2013
• Published: 03/19/2015
• Est. Priority Date: 09/16/2013
• Status: Active Grant

• Current Assignee: Conduent Business Services, LLC (Conduent, Inc.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Wu, Wencheng
• Granted Patent: US 9,716,837 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G06V 10/751 Comparing pixel values or logical combinations thereof, or feature values having positional relevance, e.g. template matching
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming

Abstract

Methods, systems and processor-readable media for parking occupancy determination. Changes in the field of view can be measured using template matching between templates derived from an original scene and a current scene with motion removed. The changes measured in the field of view can be employed to adjust data indicative of a region of interest for vision-based processing thereof if the changes measured are above a pre-determined threshold so that the impact of the changes with respect to the field of view to performance is minimized.

Claims

9-1. The method of claim 1 further comprising determining an amount and/or characteristics of said changes in said field of view if said template matching scores above said pre-determined threshold.

11. A system for parking occupancy determination, said system comprising:

a processor; and

a computer-usable medium embodying computer program code, said computer-usable medium capable of communicating with the processor, said computer program code comprising instructions executable by said processor and configured for;

measuring changes in a field of view using template matching between templates derived from at least one original scene and at least one current scene with motion removed; and

employing said changes measured in said field of view to adjust data indicative of at least one region of interest for vision-based processing thereof if said changes measured are above a pre-determined threshold so that an impact of said changes with respect to said field of view to performance is minimized.

12. The system of claim 11 wherein:

said templates comprise at least one M×

N sub-image derived from said at least one original scene and/or said at least one current scene; and

said template matching is based on a normalized cross-correlation.

13. The system of claim 11 wherein:

said templates comprise at least one feature description of said at least one region of interest; and

said template matching comprises at least one of;

SIFT-matching, SURF-matching, and a normalized cross-correlation.

14. The system of claim 11 wherein said instructions are further configure for comprising defining said at least region of interest as suitable for image registration thereof.

15. The system of claim 11 wherein said instructions are further configured for automatically learning said templates from representative image templates of said at least one region of interest, said templates representing varying image content associated with said at least one original scene.

16. The system of claim 15 wherein said automatically learning occurs offline or is updated online.

17. The system of claim 11 wherein said instructions are further configured for performing said template matching between said templates learned with respect to said at least one original scene and said at least one current scene said motion removed to determine optimal matches at a pre-determined schedule.

18. The system of claim 11 wherein said instructions are further configured for:

determining an amount and/or characteristics of said changes in said field of view if said template matching scores above said pre-determined threshold.

19. The system of claim 18 wherein said instructions are further configured for:

deriving at least one pixel location with respect to said vision-based processing if said amount exceeds said pre-determined threshold;

if said amount does not exceed said pre-determined threshold, leaving said at least one pixel location unchanged;

acquiring video of an entrance to a parking lot utilizing at least one video camera focusing on a pre-defined vision-based region of interest and a pre-defined video-based region of interest;

video processing said video via a classifier pre-trained to take into account potential camera shake disturbances to generate video output data thereof;

trajectory smoothing said video output data; and

analyzing said video output data for parking lot occupancy data, wherein an impact of camera shake with respect to said at least one video camera is minimized.

20. A processor-readable medium storing code representing instructions to cause a process for parking occupancy determination, said code comprising code to:

measure changes in a field of view using template matching between templates derived from at least one original scene and at least one current scene with motion removed; and

employ said changes measured in said field of view to adjust data indicative of at least one region of interest for vision-based processing thereof if said changes measured are above a pre-determined threshold so that an impact of said changes with respect to said field of view to performance is minimized.