Sub-Band Coding For ATV Signals Based On Spatial Domain Considerations

The effect of different finite impulse response analysis/synthesis filter pairs on sub-band coding performance is investigated based on spatial domain considerations. Deterministic as well as real video signals are used for rate and distortion evaluations of various filter pairs. A sub-band coding scheme suitable for advanced television (ATV) transmission in Broadband ISDN is then described based on the above simulations. The scheme uses the shortest kernel (2-tap) quadrature mirror filter (QMF) pairs for signal decomposition and reconstruction. The short span of the filter not only avoids quantization noise spread but also allows simple implementation in the high rate, high quality application considered here. Through successive QMF operations, the signal is decomposed into six bands to achieve low noise coding at the desired rate. The resultant coding scheme is identical to a Hadamard transform (HT) with non-constant block sizes. In addition to excellent coding performance, the hardware architecture is also much simpler than conventional transform coding or sub-band coding schemes.