PSEUDO HALF TONE PICTURE ENCODING SYSTEM

PURPOSE:To enable efficient compression and encoding by encoding a value, which calculates exclusive OR between a forecasting value to forecast an attention picture element as black or white and the value of the attention picture element in an inputted picture element, as forecasting error as a function to be mathematically calculated from the number of black picture elements in the two peripheral picture element areas of the attention picture element. CONSTITUTION:A scanning part 1, a pseudo half tone generating part 2, a line memories 3 and 4, D flip-flops 51-55, 61-65 and 71-75 for picture element delay, black picture element counting parts 81-84, an arithmetic calculation part 9 and a run length encoding part 10 are provided. The forecasting error signal is encoded by a compressing and encoding means such as run length encoding, etc., being the exclusive OR between the forecasting value of the attention picture element, which is determined by arithmetic calculation form the number of the black picture elements counting the number of the black picture elements in first and second peripheral areas of the attention picture element, and the value of the real attention picture element. Thus, the pseudo half tone picture can be efficiently compressed and encoded by an error diffusing system.