1. A scanned document image enhancement process for determining a horizontal scan line as a top registration reference scan line and a vertical pixel column as a left margin registration reference pixel column of said image, said image having scan lines including a top most scan line and pixel columns including a leftmost pixel column, said process including the steps of starting at said topmost scan line totaling scan line wise black horizontal run length values, and starting at said left most pixel column totaling pixel column wise black vertical run length values, determining a lowest accumulated vertical run length value and a lowest accumulated horizontal black run-length value, detecting on successive ones of said scan lines an increase in said accumulated horizontal black run-length values over said lowest horizontal black run-length value by a predetermined first factor, checking that over a predetermined number of said scan lines the accumulated black run-length values exceed said lowest horizontal run-length value by said predetermined factor, and selecting the next one of said scan lines to be said top registration reference scan line, detecting for on successive ones of said pixel columns an increase in accumulated vertical black run-length values over said lowest vertical black run-length value by a predetermined factor, checking that over a predetermined number of said pixel columns the accumulated black run-length values exceed said lowest vertical run-length value by said predetermined factor, and selecting the next one of said pixel columns to be said left margin registration scan line.