摘要 |
An anticounterfeit detector (ACD) does both a high and low resolution scan of a document. The video signal resulting from the low resolution scan is used to detect a selected type of image, e.g., currency, negotiable securities, etc., by using ACD hardware or software. A corrective action is taken, e.g., preferably even partial printing from the high resolution scan is prevented, the video signal is invalidated, etc., if the selected image is detected. The low resolution signal can also be obtained by decimating or low pass filtering the high resolution signal.
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