Parity bit replenishment for JPEG 2000-based video streaming
Journal on Image and Video Processing - Special issue on distributed video coding
Privacy aware image template matching in clouds using ambient data
The Journal of Supercomputing
Hi-index | 0.00 |
We consider video sequences that have been encrypted uncompressed. Since encryption masks the source, traditional data compression algorithms are rendered ineffective. However, it has been shown that through the use of distributed source-coding techniques, the compression of encrypted data is in fact possible. This means that it is possible to reduce data size without requiring that the data be compressed prior to encryption. Indeed, under some reasonable conditions, neither security nor compression efficiency need be sacrificed when compression is performed on the encrypted data (Johnson et al., 2004). In this paper we develop an algorithm for the practical lossless compression of encrypted gray scale video. Our method is based on considering the temporal correlations in video. This move to temporal dependence builds on our previous work on memoryless sources, and one- and two-dimensional Markov sources. For comparison, a motion-compensated lossless video encoder can compress each unencrypted frame of the standard "Foreman test video sequence by about 57%. Our algorithm can compress compress the same frames, after encryption, by about 33%.