This paper describes the design considerations of the digital quasi-motion colour picture transmission systems and the realization of an experimental system for low cost and low bit rate transmission. The conditional replenishment procedure as interframe coding and 1D-DST as intraframe coding are used in the system. The image sequences will be transmitted through a channel of a radio paging system or through mobile radio channel. The output bit rate is 19,2 kbit/sec. An error correction unit is used in the system, because of the relative high bit error rate of the channel. The description of the coding unit is completed with results of computer simulation.