Abstract

Image recognition by use of coherent optical processors and light diffusely scattered from the surface of an optically rough object is reported. A theoretical description is presented and shows that the image speckles are carriers for the Fourier spectra of the object at the matched spatial-filter plane. Experimental results of optical autocorrelation and cross correlation are given. The change in the intensity of the correlation peak that arises from the translation and the rotation of objects and from the lateral and axial movements of the matched filter are examined. The system is shown to be tolerant to misalignments in the positions of the object and matched filter. It is also shown that, when diffuse light is input into the coherent optical processor, the position of the Fourier plane is no longer precisely defined and spatial multiplexing would be possible.

© 1997 Optical Society of America

Angular correlation function of speckle patterns scattered from a one-dimensional rough dielectric film on a glass substrate

Jun Q. Lu and Zu-Han Gu
Appl. Opt. 36(19) 4562-4570 (1997)

Anisotropic speckle patterns in the light scattered by rough cylindrical surfaces

Germán Da Costa and José Ferrari
Appl. Opt. 36(21) 5231-5237 (1997)

Optimization of fringe pattern calculation with direct correlations in speckle interferometry

Douglas R. Schmitt and R. W. Hunt
Appl. Opt. 36(34) 8848-8857 (1997)

Partial rotation-invariant pattern matching and face recognition with a joint transform correlator

S. Chang, S. A. Boothroyd, and J. Chrostowski
Appl. Opt. 36(11) 2380-2387 (1997)

Real-time image recognition by partially coherent light

Bahram Javidi and Francis T. S. Yu
Appl. Opt. 25(14) 2365-2371 (1986)