A secure hybrid Intra/Wyner-Ziv video coding for surveillance

In this paper, we propose a secure Wyner-Ziv coding system for surveillance applications. In addition to its low coding complexity, this system allows a simple, selective and multilevel encryption for protecting a wireless transmission. Only authorized decoders can decode the video. By encrypting only a small fraction of the bits, it is possible to prevent unauthorized decoders from correctly decoding the data. It is also possible to allow a low level user to decode only a part of the frame, without a scrambled or privacy protected region of interest. Thus, every frame is divided into two groups of blocks that are coded with different coding modes and encrypted differently. One part is used to code a region of interest and another for the less important background. Our tests show that a multilevel protection is possible with privacy protection and with a small or no loss of the coding performance.