A transform optical processing system.

摘要

A Fourier transform optical processing method and system suitable for production line checking in which an electrical signal is generated by generator (2) in response to a first image and a beam (5) of coherent light is modulated by modulator (6) controlled by the electrical signal; a Fourier transform image (7) of the modulated coherent light beam is formed, and then detected by detector (8). The detector (8) 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.