US 7,480,419 B2
Image signal processing
Graham Finlayson, Norwich (United Kingdom)
Assigned to UEA Enterprises Limited, (United Kingdom)
Appl. No. 10/536,703
PCT Filed Dec. 01, 2003, PCT No. PCT/GB03/05177
§ 371(c)(1), (2), (4) Date May 27, 2005,
PCT Pub. No. WO2004/051569, PCT Pub. Date Jun. 17, 2004.
Claims priority of application No. 0227946.1 (GB), filed on Nov. 29, 2002.
Prior Publication US 2006/0110052 A1, May 25, 2006
Int. Cl. G06K 9/40 (2006.01)
U.S. Cl. 382—254  [382/274; 382/275; 358/3.26; 358/3.27] 20 Claims
OG exemplary drawing
 
1. A method of processing an image signal comprising deriving measurements of an input image signal including at least a measurement representing the luminance (1) of the signal, characterised in that the method comprises the further steps of calculating two of the following: the local mean, the local standard deviation, the local maximum and the local minimum of said measurements, computing therefrom local standard coordinates which are independent of brightness and contrast, and forming an output image signal from the standard coordinates.