Secure Visual Object Based Coding for Privacy Protected Surveillance

This paper presents a scheme for secure coding of arbitrarily-shaped visual objects. The scheme can be employed in a privacy protected surveillance system, whereby visual objects are encrypted so that the content is only available to certain entities, such as persons of authority, possessing the correct decryption key. This system may be deployed in sensitive areas requiring surveillance, but where personnel require privacy for authorized activities within the surveillance area. The encryption can be tied with the identity of human objects under surveillance so that unauthorized personnel are immediately apparent to human or computer based monitoring systems. The secure visual object coder employs Shape and Texture Set Partitioning in Hierarchical Trees (ST-SPIHT) along with partial encryption for efficient, secure storage and transmission of visual object shape and textures. The encryption is performed in the compressed domain and does not affect the rate-distortion performance of the coder. A separate parameter for each encrypted object controls the strength of the encryption versus required processing overhead. Index Terms Shape adaptive coding, security, encryption, surveillance, privacy, privacy protection, visual object coding, shape and texture coding, wavelet based coding, set partitioning in hierarchical trees (SPIHT). Corresponding Author: Karl Martin, Multimedia Laboratory, Room BA 4157, The Edward S. Rogers Sr. Department of ECE, University of Toronto, 10 King’s College Road, Toronto, Ontario, M5S 3G4, Canada, phone: 1 (416) 978 6845, FAX: 1 (416) 978 4425, e-mail: [email protected] K. Martin, and K.N. Plataniotis are with The Edward S. Rogers Sr. Department of ECE, University of Toronto, Multimedia Laboratory, Room BA 4157, 10 Kings College Road, Toronto, Ontario, M5S 3G4, Canada *Partially supported by a grant from the Natural Sciences and Engineering Research Council of Canada (NSERC) under the Network for Effective Collaboration Technologies through Advanced Research (NECTAR) project. October 12, 2007 DRAFT SUBMITTED TO IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2