JP2501646B

PURPOSE:To remove a black run which is an obstacle to picture processing by regard ing the black run longer than a line width threshold and the black run shorter than the line width threshold as a character run to constitute a character part and as a background run to constitute the oblique line, etc., of a character background part respectively, and removing the background run from picture data by changing it into a white picture element. CONSTITUTION:Line width N related to a black pattern 42 in the picture data is obtained, and the line width threshold for discriminating the black run to be changed into the white picture element is determined on the basis of this line width N. Then, the picture data is scanned in one or plural directions, and the length of the black run on a scanning line is detected, and the black run shorter than the line width threshold is detected and a rewrite signal for changing this detected black run into the white picture element is outputted. At that time, the black run longer than the line width threshold and the black run shorter than the line width threshold are regarded as the character run and as the background run respectively, and the black run regarded as the background run is changed into the white picture element. Thus, the black run which is the obstacle to the picture processing is removed from original picture data.