Correcting image errors in a shuttle scanner

摘要

A method of correcting image errors in the output from a shuttle scanner is described. A predetermined pattern that comprises a plurality of lines is printed on a record sheet by a print head that remains stationary whilst the record paper is moved in a direction perpendicular to the scanning direction. The record sheet is scanned and the scanned data stored then compared with pre-set reference data to determine any image errors. A document is scanned and the scanned document data is corrected by an amount derived from a table of corrections in accordance with the said image error. For each line of scanned document data in the direction perpendicular to the scanning direction, the number of errors is determined and the data is corrected by offsetting the pixels of scanned data in that direction. <IMAGE>