| 摘要 |
<p>A process and associated apparatus can automatically read a dot matrix code marking (2) on an article (3) even when the marking (2) has been partly obscured or damaged in some way. The process comprises capturing a video image (30) of the dot matrix code (2) and correlating points on the captured image (30) with a mask of expected dot appearance (31,33) , using a known two-dimensional correlation technique. However, the correlation is performed in accordance with certain thresholding (34) and mask adjustment criteria (38) to improve read reliability and map (35,36) the possible dot pattern in preparation for an attempt at reading the code. After automatically reorientating the map (41-46) of possible dots to a read orientation if necessary, decoding of the pattern of possible dots is then attempted by comparing it with a datum grid representing rows and columns of valid dot matrix codes (51). The process can then output a signal affirming that a valid code (54) has been found. <IMAGE></p> |
