An information processing apparatus extracts a plurality of strokes from a
multilevel image, and generates a stroke binary image. Next, the image
processing apparatus extracts feature amounts indicating the thickness
and the smoothed graylevel of a stroke in a neighboring region of a
target pixel by using each pixel belonging to each of the strokes as the
target pixel. Then, the apparatus generates a target stroke binary image
from the stroke binary image based on the distribution of the extracted
feature amounts.