JPS6448565A - Picture processor - Google Patents

Abstract

PURPOSE:To realize a density changeover function of an half tone picture with addition of simple constitution by providing an adder adding a density setting value to a picture signal read in multi-value and revising the density setting so as to switch the density of an half tone picture. CONSTITUTION:An adder 9 adds a density setting value GL inputted from a control section 10 in the unit of a picture element to an inputted digital picture signal DV and the picture signal VD being the result of addition is outputted to a comparison input terminal of a comparator 11. The comparator 11 compares the picture signal VD with a threshold TR in the unit of picture elements and when the picture signal VD is larger than the threshold value TR, the data 1 representing the black picture element is compared in the unit of picture elements and when the picture signal VD is less than the threshold value TR, a data 0 representing a white picture element is outputted as a binarized picture signal BW for each picture element. The control section 10 controls the carrying of the read original 3 by the carrier rollers 1, 2 and the operation of a dither matrix generator 12 and the density setting value GL outputted to the adder 9 is switched by a density command GC fed externally. Thus, the density of a pseudo halftone picture is switched.