In an image discrimination apparatus for discriminating a prescribed image pattern
contained in the image of an original, a plurality of marks having a prescribed
color density and disposed in a predetermined positional relationship are extracted
from an input original image and distances between the extracted plurality of marks
are calculated (S800-S811). The calculated distances between the
plurality of marks are compared with distances, stored in advance as a template,
between a plurality of marks constituting the prescribed image pattern. Whether
or not the prescribed image pattern is present in the original image is determined
in accordance with the result of the comparison (S812-S814).
