| 摘要 |
A multiple camera automatic digitizer includes a plurality of spaced video cameras mounted within a housing under a transparent digitizing surface. Multiplexing circuitry multiplexes video signals from a selected video camera into a video amplifier, the output of which is converted to a digital number representing the darkness of the point of the document most recently scanned by a presently selected one of the video cameras. In accordance with the invention, the automatic digitizer includes a microprocessor, system controls that allows selection of various ones of the video cameras to achieve digitizing of corresponding areas of a large document, and computes skew correction factors for each camera as the basis of digitizing of a plurality of permanent alignment marks on a bottom surface of a cover for the digitizing surface. The skew correction factors are used to skew correct the camera data produced by the corresponding camera. The skew corrected lateral offset of each camera is computed by the microprocessor on the basis of the digitized coordinates of the alignment points and is used to automatically compute skew corrected, offset corrected document coordinates for all of the video cameras.
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