DOCUMENT SCANNER

摘要

In a document scanner, a document (10) on a document plate (12) is scanned to produce scanned image data reproducing the contents of the document. In addition, a measurement is determined for each part of the document (10) representing the distance of the document surface at that part from the image plate (12). Each determined distance is used to select a filter parameter for filtering the.scanned image data of the corresponding document part to sharpen the image data. As a result, the scanned image data is filtered by the necessary amount to remove blur introduced by the distance of the document from the document plate (12). However, image data which is blurred in the original document (10) itself is faithfully reproduced because the filter parameter is selected so as not to distort this image data with unnecessary sharpening.