An apparatus and method for image analysis utilizing an optical-electronic hybrid device. A light source generates light through an alternating series of lenses and electronically addressable spatial light modulators to an optical correlation plane. A first modulator introduces an input image and a second modulator introduces a Fourier transformed reference image into the device. The device correlates the input image and the reference image in the optical correlation plane. The optical correlation plane feeds back information through a processor to the second modulator which varies a parameter of the reference image. The second modulator varies parameters to determine the greatest correlation between the input image and the reference image. The parameters at the point of greatest correlation are used together with the reference image to identify the input image.

Optical image analyzer using optical correlation and opto-electronic feedback

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 pattern recognition apparatus makes use of both optical templation and nal correlation techniques by using liquid crystal panels, CCD type cameras, video storage techniques, inter alia, to detect and identify electronic signal patterns transmitted thereto. The apparatus is also configured to detect pattern changes and image object movement.

Automatic pattern recognition apparatus

A technique for comparing master parts with replicas to determine differences in shapes or sizes, is disclosed, which uses interferometric techniques as disclosed. A television camera is used to scan the pattern established by illuminating the subject with a set of optical fringes. An objective lens images these on a transmission line grating. A television camera scans the transmission grating. The spatial frequencies of the subject fringes and of the grating are especially selected so that the camera can not resolve either of them but can resolve their difference. As a result, the output signals of the camera represent a contour map of the object placed on a low frequency spatial carrier, but yet, the measurement sensitivity is still determined by the spatial frequency of the subject fringes.

Surface deformation gauging system by moire interferometry

A pattern recognition and optical image processing system employing dynamically alterable magneto-optic display assemblies operating as light modulators. A first pattern is digitized and used to drive a first magneto-optic display assembly disposed in a light beam. The pattern impressed upon the light beam is sensed at the Fourier plane and digitized as a representation of the spatial filter pattern of the first pattern. A second pattern is digitized. The digitized second pattern and the digitized spatial filter pattern of the first pattern are used to drive a pair of magneto-optic display assemblies disposed in a single light beam. The resultant correlation pattern is sensed and the degree of correlation match between the Fourier transform of one pattern and the spatial filter pattern of the other pattern is used as indication of the probability of a pattern match between the first and second patterns.

Optical image processing/pattern recognition system

An optical data processing system of the coherent spatial filter type which (a) produces enhancement of the contrast of filtered images before they are photographed by providing a controllable optical attenuator in the path of the filtered light, the amount of light permitted to shine through the attenuator being a function of the intensity of the light, and (b) produces a rose diagram by providing a rotatable slit of adjustable length that is rotated in synchronism with the spatial filter, the length of the split being varied in accordance with the intensity of the light passing through the spatial filter; a camera is provided to record light from a conventional source that is collimated and passed through the rotatable slit.

Anthony Rene Barringer

Papers

Automatic transform analyzer