Patent ID: 6603111
Filing Date: 2003-08-05
Classification: G06F

Abstract:
In an optical navigation system, a method of spatially filtering an image to remove grain prior to navigation, the method comprising the steps of:(a) navigating with a first filter; (b) while navigating according to step (a), generating an ordered collection of correlation values; (c) examining the ordered collection of correlation values generated in step (b) for the presence of a transverse ridge in a correlation surface described by the values in the ordered collection; (d) when the examination in step (c) reveals a transverse ridge, then commencing to navigate with a second filter in place of the first filter; (e) while navigating according to step (d), examining an ordered collection of correlation values produced while the second filter is in use; and (e1) continuing to navigate according to step (d) while the examination in step (e) reveals the absence of a transverse ridge; and (e2) if the examination in step (e) reveals a transverse ridge, then re-instituting the use of the first filter, and resuming navigation according to step (a).