There is disclosed the following constitution in order to accurately perform
image area separation judgment by one pixel unit of a read image at a high speed
and to form an image in which character sharpness is compatible with photograph
gradation without generating a false outline in the boundary of character and photograph
areas. For this purpose, a first calculation unit calculates the sum of absolute
values of differences of image signals between a predetermined pixel in a predetermined
two-dimensional area including one noticeable pixel in the read image and the peripheral
pixel of the predetermined one pixel in the predetermined two-dimensional area,
a second calculation unit calculates the sum of calculation results with respect
to the respective pixels in the predetermined two-dimensional area, a judgment
unit judges whether the one noticeable pixel is the pixel in the photograph area
or the pixel in the character area, and the image processing, and image formation
method are changed with respect to the noticeable pixel based on the judgment result.
