1. A method for locating and adjusting a document image consisting of a plurality of pixels contained on an image capturing device, comprising: acquiring an image of a document on the device; determining the location of each edge of the document image based upon analysis of differences in luminosity values about a plurality of the pixel locations, wherein determining the location of each said edge comprises: a. quantifying a luminosity difference about the two dimensional coordinate location of each of a plurality of pixels in the two-dimensional plane of the image as determined by a first coordinate system; b. comparing each luminosity difference to a predetermined or calculated threshold value; c. creating a first set of candidate pixel coordinate locations comprising said pixel locations about which there is a luminosity difference greater than said threshold value; d. identifying a first set of clusters of candidate pixel locations, wherein said clusters comprise candidate pixel coordinate locations that are contiguous; e. determining the length of each of a plurality of clusters in said first set of clusters; f. determining the angle of each of a plurality of said first set of clusters relative to a coordinate axis; g. creating a second set of candidate coordinate pixel locations comprising the locations of those pixels within said first set of clusters that remain after discarding extraneous clusters, wherein said extraneous clusters comprise: i. clusters that are less than a minimum length; and ii. clusters with an angle relative to a coordinate axis that is outside of a specified range; h. determining a first set of pairs of coordinate values in a second two-dimensional coordinate system wherein each pair defines a line passing through one or more pixel locations in the second set of candidate coordinate pixel locations; i. selecting from said first set of pairs of coordinate values a pair of coordinate values in said second coordinate system to define an edge line in said second coordinate system; j. setting said edge line as the location of a document edge.