1. A method for scanning a document and processing the captured video image data, comprising: (a) acquiring scanned image data from a first region of the document; (b) determining an initial estimate of an image attribute using selected pixels from within the first region; (c) acquiring scanned image data from a second region of the document; (d) processing pixels within the second region in accordance with the initial estimate of the image attribute; (e) determining a second estimate of the image attribute using selected pixels in the second region of the document; (f) determining if the initial estimate is valid; and (g) if the initial estimate is not valid, rescanning the document and processing pixels within the rescanned document in accordance with the second estimate.