Compatible coding of television images, part 2. Compatible system

摘要

The coding system described in Part 1 allows compatible coding between various image formats ranging from VT to HDP and including interlaced formats. Interlaced input signals are converted into their ‘progressive equivalent’ before splitting. Compatible coding is based on the so-called Format Independent Splitting (FIS) approach: the same splitting is used whatever the input format except for interlaced inputs, which do not undergo the first horizontal splitting. Temporal correlation must be taken into account to obtain good quality images at bit rates below 1 bit per pel. Nevertheless, the hybrid scheme must be designed carefully in order to keep compatibility capabilities and avoid any drift at the compatible decoder side.