摘要 |
Method and apparatus for searching for a fiducial mark, by processing image data indicative of images of the fiducial mark and an area surrounding the fiducial mark, which images are taken by an imaging device, wherein the image data are processed by an image-data processing device, which includes: a reference-line data storing portion operable perform a step of storing at least one reference line each of which corresponds to at least one portion of a profile of the fiducial mark and the number of which is sufficient to specify the fiducial mark; a profile-data obtaining portion operable to perform a step of obtaining profile data indicative of profiles of the images taken by the imaging device, each of the profiles of the images consisting of a group of points at which an optical characteristic of the corresponding image abruptly changes; and a searching portion operable to perform a step of searching for the fiducial mark, on the basis of the profiles represented by the obtained profile data and the stored at least one reference line.
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