US 7,321,699 B2
Signal intensity range transformation apparatus and method
Stephen G. Johnson, Little Compton, R.I. (US); Norbert W. Elsdoerfer, Warwick, R.I. (US); and Charles M. Anastasia, Barrington, R.I. (US)
Assigned to Rytec Corporation, Jackson, Wis. (US)
Filed on Sep. 08, 2003, as Appl. No. 10/657,723.
Claims priority of provisional application 60/408663, filed on Sep. 06, 2002.
Prior Publication US 2004/0131273 A1, Jul. 08, 2004
Int. Cl. G06K 9/40 (2006.01); H04N 1/40 (2006.01)
U.S. Cl. 382—254  [382/168; 382/298; 358/447; 358/451] 38 Claims
OG exemplary drawing
 
1. An apparatus providing an image output signal in response to an image input signal, the device comprising:
a saturation bias identification circuit having a range of useful grey-levels output responsive to the image input signal; and
a cumulative distribution function scaling circuit having a scaled output responsive to the useful grey-levels output,
wherein the range of useful grey-levels output includes all grey-levels within a cumulative distribution function except the first unsaturated grey-level within the cumulative distribution function and the last unsaturated grey-level within the cumulative distribution function.