1. An image capture system, comprising: 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; an actuator for moving the camera field of view over a document support surface, the camera and the actuator co-operating so that a plurality of overlapping image tiles of a document can be captured at 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; characterised in that: for each image tile the camera field of view relative to the support surface and the degree of overlap between neighbouring image tiles are predetermined; 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; and the processor is adapted to use the transform data to generate from the tile data points a corrected array of tile data points with said distortion corrected and with the corrected image tiles correctly overlapped with respect to neighbouring corrected image tiles to form a composite image of the document.