System and method for tracking objects and obscuring fields of view under video surveillance

• US 20030103139A1
• Filed: 11/18/2002
• Published: 06/05/2003
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: Pelco (Schneider Electric SE)
• Original Assignee: Pelco (Schneider Electric SE)
• Inventors: Ellenberger, John C., Sexton, Robert D., Pretzer, John D., Still, Reford R.
• Granted Patent: US 7,161,615 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G08B 13/19686 Interfaces masking personal details for privacy, e.g. blurring faces, vehicle license plates
• CPC Class Codes: G11B 2220/415 Redundant array of inexpensive disks [RAID] systems
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: H04N 21/2182 involving memory arrays, e.g. RAID disk arrays RAID arrays per se G06F3/0689; use of parity to protect data in RAID systems G06F11/1008
• CPC Class Codes: H04N 21/23103 using load balancing strategies, e.g. by placing or distributing content on different disks, different memories or different servers storage management G06F3/0604; allocation of resources considering the load in multiprogramming arrangements G06F9/505; techniques for rebalancing the load in a distributed system G06F9/5083; access to distributed or replicated servers, e.g. load balancing, in data networks H04L67/1001
• CPC Class Codes: H04N 21/2312 Data placement on disk arrays data placement in general G06F3/0604
• CPC Class Codes: H04N 21/4147 PVR [Personal Video Recorder] H04N5/76 takes precedence ; arrangements for broadcast with accumulation-type receivers H04H20/40
• CPC Class Codes: H04N 21/845 Structuring of content, e.g. decomposing content into time segments

Abstract

A system and method is provided for processing video signals, tracking objects in view, and blanking fields of view in video surveillance systems. The system includes a camera having two rotational degrees of freedom, a display, and a combination of switches for routing the video signal. The displayed video signal is divided into an array of cells which may be individually masked, blanked, or blurred. The camera microcontroller captures and stores objects in view, and tracks such objects as the camera zooms, pans and tilts in spherical coordinates. Objects in view may be tracked and blanked by obscuring an agglomeration of the cells in response to a masking signal generated by the microcontroller.

Claims

1. A video surveillance system for masking an object on a display, the video surveillance system comprising:

a controller having;

a memory, the memory storing a first display coordinates data for the object, and

a processor electrically coupled to the memory, the processor converting the first display coordinates data to a second display coordinates data for the object,

the controller generating a masking signal, to obscure at least a portion of the object, defined by the second display coordinates data.

2. The video surveillance system of claim 1, further comprising:

a camera operable to zoom to at least a first magnification and a second magnification greater than the first magnification, the camera generating a raw video signal;

a switch electrically coupled to the camera, the switch receiving the raw video signal and the masking signal and generating a composite signal based on the raw video signal and the masking signal;

a video display unit coupled to the switch for displaying the composite signal; and

a programmable logic unit electrically coupled to the controller, the programmable logic unit controlling the switch to display the composite signal on the display unit, the composite signal comprising a plurality of frames, each frame having a plurality of cells, each cell displaying an image signal in response to the raw video signal and the masking signal,

the first display coordinates data comprising a first horizontal display position, a first vertical display position, and the first magnification for each of a plurality of object vertices of the object, and the second display coordinates data comprises a second horizontal display position and a second vertical display position for each of the plurality of object vertices.

3. The video surveillance system of claim 2,

wherein the processor calculates the second horizontal display position and second vertical display position of an object vertex based on the first display coordinates data and the second magnification.

4. The video surveillance system of claim 3,

wherein each of the plurality of cells includes one or more blanking cells defining a blanking window having a plurality of blanking window vertices, and

wherein the programmable logic unit is programmed to switch the masking signal on at the second magnification, and at a magnification greater than the second magnification, the masking signal generating a blanking sub-window as the image signal for each blanking cell.

5. The video surveillance system of claim 4,

wherein the plurality of blanking window vertices are equal in number to the plurality of object vertices, each of the blanking window vertices having a horizontal display position and a vertical display position substantially the same as the second horizontal display position and the second vertical display position, respectively, of one of the object vertices.

6. The system of claim 4, further comprising:

a video smear circuit coupled to the switch, the video smear circuit having a filter, the filter filtering the masking signal to produce a video smear signal for each blanking sub-window.

7. The video surveillance system of claim 6,

wherein the filter is a lowpass filter.

8. The video surveillance system of claim 2,

wherein the camera is operable to pan in a first rotational degree of motion to a plurality of pan positions including at least a first pan position and a second pan position, and is operable to tilt in a second rotational degree of motion to a plurality of tilt positions including at least a first tilt position and a second tilt position,

wherein the memory further stores an object coordinates data for the object, the object coordinates data including a latitude and a longitude for each of the object vertices, based on the first tilt position, the first pan position, and the first display coordinates data, and

wherein the processor calculates the second horizontal display position and the second vertical display position of an object vertex based on the latitude and longitude of the object vertex, the second pan position, the second tilt position, the second magnification.

9. The video surveillance system of claim 8,

wherein each of the plurality of cells includes one or more blanking cells defining a blanking window having a plurality of blanking window vertices, and

wherein the programmable logic unit is programmed to switch the masking signal on at the second magnification, and at a magnification greater than the second magnification, the masking signal generating a blanking sub-window as the image signal for each blanking cell.

10. The video surveillance system of claim 9,

wherein the plurality of blanking window vertices are equal in number to the plurality of object vertices, each of the blanking window vertices having a horizontal display position and a vertical display position substantially the same as the second horizontal display position and the second vertical display position, respectively, of one of the object vertices

11. The system of claim 10, further comprising:

a video smear circuit coupled to the switch and having a filter, the filter filtering the masking signal to produce a video smear signal for each blanking sub-window.

12. The video surveillance system of claim 11,

wherein the filter is a lowpass filter.

13. A method of video surveillance using a video display, comprising:

acquiring a video signal with a zoomable camera,

setting a first zoom setting for the camera to produce a first video image on the display from the video signal,

generating and storing a first blanking area data corresponding to the first blanking area,

setting a second zoom setting for the camera to produce a second video image on the display from the video signal,

processing the first blanking area data to generate a second blanking area data corresponding to a second blanking area,

displaying a mask object on the display over the second blanking area on the second video image.

14. A method of video surveillance using a video display and a camera, comprising:

storing a set of object coordinates for an object appearing in a first view,

moving the camera to a second view,

converting the object coordinates to display coordinates for the object appearing in the second view,

generating a masking signal,

obscuring at least a portion of the object in the second view using the masking signal.

15. The video surveillance method of claim 14, further comprising:

setting the camera to a first zoom setting,

moving the camera to point to a plurality of object vertices appearing in the first view of the camera, each object vertex having a vertex data,

calculating the latitude and longitude of each vertex as a function of the camera pan position, the camera tilt position, the first zoom setting, the horizontal display position of the vertex, and the vertical display position of the vertex,

storing the latitude, longitude, and zoom setting of each object vertex in a memory,

moving the camera to at least one of a second camera pan position and a second camera tilt position,

setting the camera to a second zoom setting, and

calculating a second horizontal display position and second vertical display position for each object vertex as a function of the second camera pan position, the second camera tilt position, the latitude and the longitude of the vertex.

16. The method of claim 15, wherein every step is performed by an integrated camera and camera control system.

17. The video surveillance method of claim 15,

wherein the vertex data includes a camera pan position, camera tilt position, a latitude, a longitude, a first zoom setting, a horizontal display position, and a vertical display position.

18. The video surveillance method of claim 17, further comprising:

generating a composite video signal having a plurality of cells for each frame,

calculating a cell latitude and cell longitude for each cell, and

comparing the cell latitude and cell longitude of each cell with the latitude and longitude of each object vertex to determine if the object is in the second view.

19. The video surveillance method of claim 18,

wherein each object is defined by a polygon having a plurality of segments, each segment comprising two object vertices, and further comprising

for each cell, counting the number of times a virtual ray having a zero change in latitude and continuously extending in a positive longitudinal direction from the cell intersects with the plurality of segments to produce an intersection count for each cell.

20. The video surveillance method of claim 19, further comprising:

generating a blanking window having a plurality of blanking window vertices, the blanking window obscuring at least a portion of the object in the second view.

21. The video surveillance method of claim 20,

wherein the plurality of blanking window vertices are equal in number to the plurality of object vertices, each of the blanking window vertices having a horizontal display position and a vertical display position substantially the same as the second horizontal display position and the second vertical display position, respectively, of one of the object vertices.

22. The method of claim 20, further comprising:

generating a blanking sub-window in response to the masking signal for each cell having an intersection count that is odd, the blanking sub-window replacing the cell in the composite video signal, the blanking window being defined by the blanking sub-windows.

23. The method of claim 22,

wherein the blanking sub-window is generated by filtering the composite video signal with a lowpass filter.