Publication:
Shift and scale invariant preprocessor.

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Authors
Huston, Norman E., Jr.
Subjects
shift invariance
scale invariance
Mellin transform
classification preprocessor
range only radar classification
Advisors
Wilson, L.A.
Hamming, Richard W.
Date of Issue
1981
Date
December 1981
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
A preprocessor is designed to extract a set of features that enhance natural clustering by removing extraneous information. The design rerroves time shift and scale dependence by taking advantage of invariant properties of a Fourier transform followed by a Mellin transform. The preprocessor is realized using an FFT and a Mellin transform with a conventional error correction term. The error term proves to be indeterminate, but the error's bound is identified as the envelope for Mellin correction terms. Properties of the Mellin transform are employed to modify the signal so that the error correcting is no longer required. The resulting algorithms are tested with variously scaled inputs for which closed form solutions are known. With a verified modification in place, the preprocessor produces features that are invariant to shifting and scaling, while retaining enough information to classify canonic shapes, A method of improving performance is introduced.
Type
Thesis
Description
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Department
Electrical Engineering
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Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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