RESUMO
Access to security spaces and the verification of credit cards require, ideally, a simple and inexpensive system that combines accuracy with a high resistance to compromise. We have been investigating such a system. This system incorporates a novel fingerprint input arrangement that permits the use of optical pattern recognition for fingerprint verification in real time. Test results together with design considerations are reported.
RESUMO
An optical-digital approach to fabricating matched spatial filters for multiple image recognition is discussed. Multiplexing is accomplished in the Fourier plane following optical transformation. A screening filter is formed digitally by adding or subtracting the intensity spectra of the transformed images to be recognized or ignored. This screening filter is then used to construct optically a composite image which contains the essential features of the various images to be recognized and from which compromising features have been deleted. The composite image is then used to record the desired filter. Initial results for both recognition and discrimination are presented.
RESUMO
A pattern recognition system that uses incoherent spatial filtering to recognize images directly from a narrowband phosphor television monitor is described. Images of real objects are captured with a television camera. These images are then edge-enhanced electronically and displayed on the TV monitor. The monitor output is used directly as the input to a holographic correlator. An optical multichannel analyzer at the correlation plane is used to analyze the shape of the correlation function and to determine the position of its peak. Experimental results agree well with theory. Concepts for handling rotation, aspect angle, and scale variations of the input are discussed.
