METHOD FOR TRACKING AN OBJECT THROUGH AN ENVIRONMENT ACROSS MULTIPLE CAMERAS

• US 20110115909A1
• Filed: 11/15/2010
• Published: 05/19/2011
• Est. Priority Date: 11/13/2009
• Status: Abandoned Application

• Current Assignee: Pixel Velocity
• Original Assignee: Pixel Velocity
• Inventors: Lennington, John W., Mustafa, Ali M., Sternberg, Stanley R., McCubbrey, David L.
• Application Number:
  US12/946,758
• Publication Number:
  US 20110115909A1
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 2210/04 Architectural design, interior design
• CPC Class Codes: G06T 7/292 Multi-camera tracking
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: G08B 13/19645 Multiple cameras, each having view on one of a plurality of scenes, e.g. multiple cameras for multi-room surveillance or for tracking an object by view hand-over
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A method and system for tracking a subject through an environment that includes collecting visual data representing a physical environment from a plurality of cameras; processing the visual data; constructing a model of the environment from the visual data; and cooperatively tracking a subject in the environment with the constructed model and processed visual data.

Claims

1. A method for tracking a subject through an environment comprising:

collecting visual data representing a physical environment from a plurality of cameras;

processing the visual data;

constructing a model of the environment from the visual data; and

cooperatively, tracking a subject in the environment with the constructed model and processed visual data.

2. The method of claim 1, wherein the processing of collected visual data is based on the constructed model.

3. The method of claim 2, wherein the model is a 3D model of subjects in a simulation of the environment, wherein the model of the environment is preconfigured.

4. The method of claim 1, wherein constructing a model of the environment includes modeling camera components, object components of the environment, and subject components that are subject to tracking.

5. The method of claim 4, wherein object components of the environment include static and dynamic object components.

6. The method of claim 4, wherein the subject models have associated environment permissions defining the interactions of the modeled physical object in the environment of the model, and further including activating an alert response upon violation of environment permissions of a subject.

7. The method of claim 6, wherein the environment permission is a defined portion of the environment that a subject may be located.

8. The method of claim 4, wherein constructing a model further includes modeling conceptual components that are used to relate visual data and the model during tracking.

9. The method of claim 8, wherein the conceptual components include a sprite, a screen, and a shadow and comprising:

modeling a subject position in the environment with a sprite;

modeling visual data as a projection from a camera onto a surface normal and displaced from a position of the camera in the environment;

simulating a projection from the camera position to the sheet; and

identifying a shadow cast by the sprite interrupting the projection on the sheet.

10. The method of claim 9, wherein cooperatively tracking includes comparing shadows to processed image data.

11. The method of claim 10, wherein processing visual data includes detecting a binary connected region of an image of the visual data;

and wherein cooperatively tracking includes associating the binary connected region with a shadow of a sprite and updating sprite position according to the position of the binary connected region in the visual data.

12. The method of claim 11, wherein position of a sprite is updated if the updated position satisfies kinematic properties of the subject assigned to the sprite.

13. The method of claim 4, wherein constructing a model further includes predicting motion of a subject.

14. The method of claim 13, wherein predicting motion includes predicting motion of a sprite through a portion of the environment with no visual data by using calculating motion from kinematic properties of the subject.

15. The method of claim 4, further comprising defining a condition in the model for automatic enrollment of subject tracking;

and wherein collaboratively tracking includes automatically selecting a subject for tracking upon satisfying the defined condition.

16. The method of claim 4 further comprising calibrating the model and the visual data by adjusting the modeled camera components to maximize alignment of the model and the visual data the camera associated with the camera component.

17. A system for tracking a subject in an environment comprising:

an imaging system to capture image data with a plurality of cameras arranged in the environment;

a tracking system for tracking a subject in an environment that includes;

an image processing system for processing the captured image data and in communication with a modeling system

a modeling system that maintains a model of the environment according to the processed image data and communicates image processing updates to the image processing system

18. The system of claim 17 wherein the image processing system includes an image processor for each camera of the plurality of cameras.

19. The system of claim 17, wherein the plurality of cameras are distributed in an environment with at least two cameras having at least partially overlapping inspection zones

20. The system of claim 17, wherein the modeling system includes a model of camera object components and subject component assigned to a sprite;

wherein the sprite is associated with a shadow resulting from a projection onto a modeled sheet; and

the imaging processing system includes calculated binary connected regions of visual data that can be associated with the shadows for tracking.