1. A method for processing a digitally captured image that comprises an imaged document, said method comprising: detecting graphical information related to spatial discontinuities of said digitally captured image; detecting lines from said detected graphical information; computing effective area parameters for quadrilaterals associated with ones of said detected lines, wherein each effective area parameter for a respective quadrilateral equals an area of the respective quadrilateral modified by at least a corner matching score that is indicative of a number of connected edge pixels in corners of said respective quadrilateral; and selecting a quadrilateral of said quadrilaterals that possesses a largest effective area parameter.