Abstract: 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.