PURPOSE: To improve the picture quality by discriminating a binary-coded threshold value at each region from the density detected by the 1st original scanning and using the said threshold value at the 2nd original scanning so as to apply binary coding.

CONSTITUTION: A signal detected by an image pickup element 20 at the 1st original scanning is written in a line RAM 50 via an AD converter 44 and a shading circuit 46. A CPU 42 discriminates the attribute of the original based on a data in the RAM 50. Whether binary-coding or dither is selected depending on a character picture or an intermediate tone picture and its threshold value is written in an attribute RAM 56 at each region of the picture. A signal obtained at the 2nd original scanning is compared with an output of the attribute RAM 56 or a pattern generating circuit 58 at a comparator circuit 48, the result is binary-coded and outputted to an output circuit 54. Thus, even when the density of the background of the original changes, a proper binary coding picture is obtained and the quality of picture is improved.