The Use of Complex Spatial Frequency Filters in Correlation Processes


A method of solving pattern recognition problems is to correlate the unknown data with the known pattern. Where the data is available in two-dimensional transparency form it is convenient to use optical systems; it can be shown that a coherent optical system, using a complex filter corresponding to the pattern being sought, can perform the required correlation operation. The method of setting up the coherent optical system and of constructing the complex filter are described. The limitations of the recording material used in making the filter are discussed and results are presented showing the effect of these limitations on the output of the system. Problems concerned with the practical use of the optical correlator are discussed, including the effect of optical aberrations and difficulties in using photographic input data. A method of overcoming some of the recording limitations is also presented. Finally, some applications are described in which complex spatial filters have been used. The merits and disadvantages in this approach to pattern recognition are discussed and some suggestions for future applications are given.

Divisions: College of Engineering & Physical Sciences
Additional Information: Copyright © Gordon E Keyte, 1970. Gordon E Keyte asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.
Institution: Aston University
Uncontrolled Keywords: complex spatial frequency filters,correlation processes
Last Modified: 19 Apr 2024 10:19
Date Deposited: 28 Oct 2019 15:35
Completed Date: 1970
Authors: Keyte, Gordon E.

Export / Share Citation


Additional statistics for this record