JPS57120180A - Binary coding processing method of picture information - Google Patents

Abstract

PURPOSE:To simplify both the logic of the binary coding process for expression of the half tone and the circuit of the device, by setting the binary coding reference level at a high and low values for each picture element at a prescribed minor unit picture area section and then obtaining a binary coded picture signal to which a concentration and gradation process is applied. CONSTITUTION:The binary coding reference level data of 64 pieces (8X8) are stored in a dither matrix ROMDM-ROMP in a constitution in that a binary coding process is carried out in case 32 bits are read in the secondary scanning direction (y) during a main scan. By this dither matrix, an address is decided by a secondary scanning counter CO2P and a main scanning counter CO3P, and the binary coding reference level data is read out to each picture element in (8X8) sections. This level data is then converted into the analog voltage by a D/A converte DA to be applied to a comparator CPA in the form of the threshold level. The analog picture signal is applied to the comparator CPA, and the comparator CPA delivers the binary coded picture signals of 1 and 0 if the analog picture signal is higher and lower than the threshold level respectively.