| 摘要 |
<p>PROBLEM TO BE SOLVED: To quickly and accurately detect the center position of an alignment pattern to shorten the read time as the result in the case of read of a two-dimensional code having the alignment pattern. SOLUTION: Eight check points are set one cell apart from the center position obtained by calculation in the periphery of the center position, and a brightness pattern of nine points consisting of the calculated center position and eight peripheral check points is compared with nine reference patterns (a) to (i) to find the reference pattern coinciding with the brightness pattern. Since reference patterns (a) to (i) are different in shape data and are set so that each of them may include a center cell (e) of the alignment pattern, a part of the reference pattern coinciding with the brightness pattern which the center cell (e) of the alignment pattern corresponds to can be discriminated if the reference pattern coinciding with the brightness pattern is found. For example, if the reference pattern (a) coincides with the brightness pattern, the right and lower cell corresponds to the center cell (e). Consequently, the center position of this specified center cell is calculated to accurately specify the center position.</p> |
