Abstract
A method of image enhancement and real-time input of 3-D, microscopic phase objects into a coherent optical pattern recognition system is described. The method consists of directing a low-power laser beam into a microscope objective to produce a real, magnified, coherent image of the specimen under test. The image plane is followed by two successive Fourier transform (FT) planes. In the first FT plane, low and high frequency spatial filters, one of which is photographically produced, are used as pre-processing filters to enhance the image quality. The enhanced signal is imaged from the first FT plane to the second FT plane which contains a matched spatial filter used for specimen identification. The system does not require an expensive incoherent-to-coherent light transducer and in addition, is capable of utilizing both phase and amplitude information from 3-D objects. Examples of results are given.
Similar content being viewed by others
References
A. Vander Lugt, F. Rotz, A. Klooster: InSymposium on Optical and Electro-Optical Information Processing, ed. by J. T. Tippett, D.A. Berkowitz, L.C. Clapp, C.J. Koester, A. Vanderburgh, Jr. (MIT Press, Cambridge, MA, 1965) pp. 125–141
M. De, A.W. Lohmann: Appl. Opt.6, 2171–2175 (1967)
E.N. Leith: Proc. IEEE59, 1305–1318 (1971)
R. Wohlers, R. Herold, S. Jost, J. Lisa, J. Mendelsohn, B. Pernick, R.E. Koop: “Coherent Optical Processing Techniques for Screening Cervical Smears”, Grumman Research Department Report RE-519 (1976)
K. Preston:Coherent Optical Computers (McGraw-Hill, New York 1972)
J.C. Vienot, J. Bulabois, L.R. Guy: Optics Comm.2, 431–434 (1971)
C.B. Tropper: J. Physiol.11, 297–302 (1975)
K.L. Dickson, J.P. Slocomb, J. Cairns, Jr., S.P. Almeida, J.K.T. Eu: InBiological Monitoring of Water and Effluent Quality, ed. by J. Cairns, Jr., K.L. Dickson, G.F. Westlake (ASTM, Philadelphia, PA 19 ) 121–132
S.P. Almeida, J.K.T. Eu: Appl. Opt.15, 510–515 (1976)
J. Grinberg, A. Jacobson, W. Bleha, L. Miller, L. Fraas, D. Boswell, G. Myer: Opt. Eng.14, 217–225 (1975)
S.L. Hou, D.S. Oliver: Appl. Phys. Lett.18, 325–328 (1971)
M.E. Cox: Microscope22, 361–366 (1974)
R.F. VanLigten, H. Osterberg: Nature211, 282–283 (1966)
P. Hutzler: Appl. Opt.16, 2264–2272 (1977)
R.L. Lowe: J. Phycol.11, 415–424 (1975)
B.J. Thompson: InOptical Transforms, ed. by H. Lipson (Academic Press, New York 1972) pp. 267–298
J. Santamaria, P.T. Gough, D.W. Warren: Appl. Opt.16, 1513–1520 (1977)
D. Casasent, A. Furman: Appl. Opt.16, 1662–1669 (1977)