E.i. Dupont De Nemours and Company

Gregory S Mercurio

Roeland M Hekker

Izhak M Livny

David P Casasent

Marc A Franke

The Fourier transform optical processing system of the present invention includes generating an electrical signal in response to a first image and modulating a beam of coherent light with means that is responsive to the electrical signal. A Fourier transform image of the modulated coherent light beam is formed, an then detected. The detector provides a second electrical signal representative of the Fourier transformed image. Other aspects of the invention include comparing the second electrical signal to a reference electrical signal for producing an output signal representing any differences; optically preprocessing the image; detecting the Fourier transform image and generating signals representative of its Fourier transform characteristics; and modulating a coherent light beam using a liquid crystal or other spatial light modulating device.

Transform optical processing system

A transform digital optical processing system generates a transform signal of an image. Fourier or other well-known transforms may be employed. The transform signal may be generated in one of two ways: optically or electronically. In optical generation a two dimensional object is generated by modulating a beam of coherent light with an image of the object. A transform image of the modulated coherent light beam is formed, using an optical transform element. The optical transform is then stored in a two dimensional buffer. The transform signal may also be generated electronically by storing a digital video image of an object and generating a Fourier or other transform of the digital video image using vector processing chips or other commercially available digital transform generating computers. This digitally generated information may be analyzed and classified through a neural network type processor. The two-dimensional transform data is then processed to obtain the inspection or other characteristics for comparison against predetermined characteristics. The two dimensional transform is divided into two types of zones, namely wedges and rings. The transform data is then mapped into a corresponding wedge and ring, and the data for each wedge and ring is accumulated or summed to obtain data values. It has been found that the summed wedge and ring data values can accurately characterize an image for inspection or other comparison purposes.

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Fairfield, IA, United States of America

Gregory S Mercurio