A method for identifying and correcting for spatial variation within
scanning bars includes performing diagnostic scans of at least one sheet,
in which a sheet(s) is scanned in various orientations and translations,
with each of the orientations identified. The diagnostic scans are
registered with one of the individual diagnostic scans to produce
registered scans. The registered scans are averaged to create a master
scan corresponding to the sheet, such that the master scan is indicative
of the spatial variation within the sheet.