INFORMATION TRANSMISSION SYSTEM

摘要

PURPOSE:To reduce the transmission information quantity without deteriorating the fidelity to an original signal by transmitting a basic picture element data by a conventional quantized bit number and an additional picture element data by a quantized bit number less than the conventional bit number. CONSTITUTION:The E mode data (additional picture element data) and the C mode data (basic picture element data) are stored respectively in field memories 25, 26 and the E mode data is inputted further to a forecast differential coder 27. The coder 27 calculates the difference between the basic picture element data and the additional picture element data respectively, uses the difference to decide the quantizing step of a DPCM coder and the result is outputted as the E mode data. Then a switch 7 selects the C or E mode based on the result of discrimination of a mode discrimination circuit 4 and outputs the result.