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Title: Position, rotation, and intensity invariant recognizing method

Abstract

A method for recognizing the presence of a particular target in a field of view which is target position, rotation, and intensity invariant includes the preparing of a target-specific invariant filter from a combination of all eigen-modes of a pattern of the particular target. Coherent radiation from the field of view is then imaged into an optical correlator in which the invariant filter is located. The invariant filter is rotated in the frequency plane of the optical correlator in order to produce a constant-amplitude rotational response in a correlation output plane when the particular target is present in the field of view. Any constant response is thus detected in the output plane to determine whether a particular target is present in the field of view. Preferably, a temporal pattern is imaged in the output plane with a optical detector having a plurality of pixels and a correlation coefficient for each pixel is determined by accumulating the intensity and intensity-square of each pixel. The orbiting of the constant response caused by the filter rotation is also preferably eliminated either by the use of two orthogonal mirrors pivoted correspondingly to the rotation of the filter or the attaching of a refracting wedgemore » to the filter to remove the offset angle. Detection is preferably performed of the temporal pattern in the output plane at a plurality of different angles with angular separation sufficient to decorrelate successive frames. 1 fig.« less

Inventors:
; ;
Issue Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (USA)
OSTI Identifier:
7028999
Patent Number(s):
-US-A6096434
Assignee:
SNL; EDB-88-182142
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; HOLOGRAPHY; PATTERN RECOGNITION; INFORMATION SYSTEMS; DESIGN; INFORMATION RETRIEVAL; INVENTIONS; 990300* - Information Handling

Citation Formats

Ochoa, E., Schils, G.F., and Sweeney, D.W. Position, rotation, and intensity invariant recognizing method. United States: N. p., 1987. Web.
Ochoa, E., Schils, G.F., & Sweeney, D.W. Position, rotation, and intensity invariant recognizing method. United States.
Ochoa, E., Schils, G.F., and Sweeney, D.W. Tue . "Position, rotation, and intensity invariant recognizing method". United States.
@article{osti_7028999,
title = {Position, rotation, and intensity invariant recognizing method},
author = {Ochoa, E. and Schils, G.F. and Sweeney, D.W.},
abstractNote = {A method for recognizing the presence of a particular target in a field of view which is target position, rotation, and intensity invariant includes the preparing of a target-specific invariant filter from a combination of all eigen-modes of a pattern of the particular target. Coherent radiation from the field of view is then imaged into an optical correlator in which the invariant filter is located. The invariant filter is rotated in the frequency plane of the optical correlator in order to produce a constant-amplitude rotational response in a correlation output plane when the particular target is present in the field of view. Any constant response is thus detected in the output plane to determine whether a particular target is present in the field of view. Preferably, a temporal pattern is imaged in the output plane with a optical detector having a plurality of pixels and a correlation coefficient for each pixel is determined by accumulating the intensity and intensity-square of each pixel. The orbiting of the constant response caused by the filter rotation is also preferably eliminated either by the use of two orthogonal mirrors pivoted correspondingly to the rotation of the filter or the attaching of a refracting wedge to the filter to remove the offset angle. Detection is preferably performed of the temporal pattern in the output plane at a plurality of different angles with angular separation sufficient to decorrelate successive frames. 1 fig.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {9}
}