Picture encoding methods for use in the H4 and H3 channels of the ISDN were discussed, taking into consideration the attainable picture quality and the necessary amount of hardware. In view of the anticipated introduction of distributive services both in the 625-line standard and in an HDTV standard yet to be defined, the transmission rate on the subscriber Une should be 135 Mbit/s. Taking into account all marginal constraints and the hardware complexity in the subscriber's equipment, a method should be chosen that operates with scanning rates of 13.5 MHz for the luminance and 3.375 MHz for each color difference signal with line-continuous transmission.
展开▼
