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Abstract : |
In this paper, we develop a transmission system, referred to as Dual Stream JPEG (DSJ), that improves the resiliency of JPEG video streams by unifying layered encoding with image scrambling techniques. Whereas layered encoding techniques naturally provide resiliency to isolated loss of low priority image data, scrambling techniques make it possible to distribute burst losses throughout the image. In DSJ, this unification is instantiated by employing the discrete cosine transform (DCT) to convert each 8x8 pixel block of an image into frequency domain, partitioning the resultant blocks into high-priority DC coefficients and low-priority AC coefficients, and then scrambling the transmission of encoded blocks of AC coefficients. Furthermore, DSJ defines an adaptation layer that implements efficient error detection and recovery by including the sequence number and offset (relative to the beginning of the cell payload) of blocks carried in each cell. We have evaluated the performance of DSJ through extensive simulations. We present and analyze our results., |
