Method and apparatus for indicating a field of view for a document camera

摘要

A document camera is described for capturing an electronic image of a document, for subsequent optical character recognition. In order to avoid the need for a user to look through a viewfinder of the camera, the camera comprises a projector for projecting an optical field of view indicator on to the document. The user can see the projected indicator on the document page, indicating the effective field of view of the camera. The camera may include auto-focus and zooming mechanisms. In one form, the camera processes a detected image to determine a capture zone corresponding to whole regions of the document falling entirely within the field of view. The projected indicator is controlled to indicate only the capture zone. When the image is to be captured, the camera zooms in to the capture zone to capture the image at maximum resolution. <IMAGE>