Sub-band coding of HDTV images using GQMF

The author describes a low complexity intraframe sub-band image coding algorithm suitable for video coding applications. A new class of quadrature mirror filter (QMF), called the generalised quadrature mirror filter (GQMF), with smaller overall delay, is introduced. In this approach, the spectra of the HDTV signals are first decomposed into smaller frequency bands where the baseband is DPCM encoded and the high bands are PCM encoded. For optimum performance, an efficient entropy coder is designed that significantly reduces the overall bit rate. It is shown that high quality HDTV images can be obtained at bit rates as low as 34 Mbit/s with a considerable reduction in complexity.