SECURE AND PRIVATE TRACKING ACROSS MULTIPLE CAMERAS

• US 20150227814A1
• Filed: 04/22/2015
• Published: 08/13/2015
• Est. Priority Date: 12/31/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Chu, Chun-Te, Jung, Jaeyeon, Liu, Zicheng, Mahajan, Ratul
• Granted Patent: US 9,977,991 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/51 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06F 7/02 Comparing digital values G06F7/06, G06F7/22, G06F7/38 take precedence
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20036 Morphological image processing
• CPC Class Codes: G06T 2207/20081 Training; Learning
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/292 Multi-camera tracking
• CPC Class Codes: G06V 20/40 in video content extracting overlay text G06V20/62; video retrieval G06F16/70; processing of video elementary streams in video servers H04N21/234; processing of video elementary streams in video clients H04N21/44
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A technique for multi-camera object tracking is disclosed that preserves privacy of imagery from each camera or group of cameras. This technique uses secure multi-party computation to compute a distance metric across data from multiple cameras without revealing any information to operators of the cameras except whether or not an object was observed by both cameras. This is achieved by a distance metric learning technique that reduces the computing complexity of secure computation while maintaining object identification accuracy.

Claims

1. A system comprising:

one or more processing elements;

an object detection module communicatively coupled to or integrated with the one or more processing elements and configured to detect a first object when the first object is in view of a first video camera associated with a first site;

a feature vector module communicatively coupled to or integrated with the one or more processing elements and configured to extract a first feature vector from the first object;

a preprocessing module communicatively coupled to or integrated with the one or more processing elements and configured to perform local processing of the first feature vector by normalizing the first feature vector and quantizing the first feature vector into an integer value to form a first secure input;

a garbled circuit generator communicatively coupled to or integrated with the one or more processing elements and configured to generate a Boolean circuit for a jointly-computed portion of a vector distance function, wherein inputs to the Boolean circuit comprise the first secure input from the first site and a second secure input from a second site, the second secure input generated by processing a second feature vector generated from a second object that was in view of a second video camera associated with the second site;

a match query module communicatively coupled to or integrated with the one or more processing elements and configured to send a query to the second site to request participation in solving the jointly-computed portion of the vector distance function; and

a joint computation module communicatively coupled to or integrated with the one or more processing elements and configured to solve the jointly-computed portion of the vector distance function with the second site to determine if the first object is the same as the second object.