A real picked-up image containing an image of a position detection mark 13
is
picked up by an image pickup unit 1 and is stored in image memory 5 through
an interface section 2. A CPU 6 generates a pseudo image on which
change in the image pickup conditions is reflected from the stored real picked-up
image and detects an image of an object using a predetermined image processing
parameter from the generated pseudo image. If the object image is erroneously detected
from the pseudo image, the image processing parameter is changed so that object
image is not erroneously detected.
