Hierarchical HDTV/SDTV compatible coding using Kalman statistical filtering

This paper addresses the issue of hierarchical coding of digital television . A two-layer coding scheme is presented to provide compatibility of standa rd-definition television (SDTV) and high-definition television (HDTV), The scheme is based on a spatio-temporal pyramid coding technique. We address t he problem of interlaced-to-interlaced two-layer compatible coding where bo th layers are interlaced, The resolution translation is Important for the v isual quality of the SDTV layer and for the performance of the HDTV layer, A motion-compensated up/down deinterlacing scheme is used to improve the pe rformance. A spatio-temporal averaging technique is used to give a better c ompatible prediction so that the HDTV layer has a high compression performa nce, To offer an improved prediction, systematic analysis of the remaining statistical redundancy of the enhancement signal is conducted. Based on an autoregressive model of the difference signal, a Kalman statistical filteri ng is used to exploit such a redundancy, We combine a recursive filtering a nd discrete cosine transform (DCT) coding using QR decomposition, where Q i s an orthonormal matrix and R is an upper triangular matrix, The error accu mulation is cancelled in the DCT frequency domain. Our results show peak si gnal-to-noise-ratio improvements over simulcast as high as 1.2 dB. The new technique, which is referred to as spatial scalability using a Kalman filte r (SSKF), achieves a comparable or better picture quality than that of a no nscalable approach for high-quality video coding. The near optimal performa nce is demonstrated by the white Gaussian noise property of the residual si gnal.