Image analysis system employing filter look-up tables

US4941191A · kind A · utility

Assignee

• O-I Neg TV Products, Inc. Formerly known as Owens-Illinois Television Products, Inc.) · US

Inventors

• John W. Miller · Bel Air, US
• Peter Miller · New London, US

Key dates

• Filing date: Jan 4, 1988
• Grant date: Jul 10, 1990
• Expiry date: Jan 4, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G06T2207/30164
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An image processing system and filters applicable to such a system wherein digitized discrete signals, as pixel signals, are processed in a look-up table according to the sum of the current digitized value of a discrete signal multiplied by a factor and the digitized value of the signal from the look-up table for a preceding discrete signal multiplied by one less the factor for low pass filtering; and wherein high pass filtering is the difference between a factor times the current digitized value of a discrete signal and the digitized value of the low pass filter from the look-up table for a preceding discrete signal multiplied by a factor. Two dimensional filtering in a two dimensional array of pixels is afforded by identifying pixel signals by row and column and high pass filtering in pixel columns from row-to-row. Vector combinations of row and column filtered values are employed in a system for electro-optical inspection of the image of a product.