The present invention relates to the use of an image capture system having an
electronic camera for platenless document imaging. The system comprises: an electronic
camera with an electronic detector and a lens with a field of view for imaging
on the detector a portion of a document; a support by which the camera can be positioned
to view the document; an actuator for moving the camera field of view so that a
plurality of overlapping image tiles of a document can be captured at predetermined
different locations over the support surface, each image tile having an array of
tile data points and being subject to some expected perspective and/or camera distortion
relative to the support surface; and a processor by which the plurality of image
tiles may be joined into a composite image of the document. The processor includes
a memory which stores transform data for each image tile, the transform data relating
both to the expected distortion and to the predetermined overlap between image
tiles. The processor is adapted to use the transform data to generate from the
tile data points a corrected array of tile data points with the distortion corrected
and with the corrected image tiles correctly overlapped to form a composite image
of the document.