
Accession Number : AD0723662
Title : WalshHadamard Transformations in Image Processing,
Corporate Author : CALIFORNIA UNIV LOS ANGELES SCHOOL OF ENGINEERING AND APPLIED SCIENCE
Personal Author(s) : Alexandridis, Nikitas A.
Report Date : MAR 1971
Pagination or Media Count : 133
Abstract : A technique is presented for obtaining the WalshHadamard (WH) transform of a picture in realtime by operating separately on each picture line. Overlap of scanning and computations, results in savings of the total time required to transform a picture. For digital computer processing core storage requirements are reduced. The technique leads to the hardware implementation of a machine capable of performing realtime parallel WH transformation. The 'axissymmetry' parameter of the Walsh functions is defined and the axissymmetry number and the period of a Walsh function are derived from its sequency number. Analysis of Walsh spectra establishes the relations between image samples and Walsh spectrum coefficients. Walsh functions are used in designing a feature extractor. The axissymmetry histogram is obtained from the Walsh spectrum of a pattern by adding the squares of the spectrum coefficients that correspond to a given axissymmetry number tau and plotting these against tau. Axissymmetry histograms result in great dimensionality in the feature space. (Author)
Descriptors : *PATTERN RECOGNITION, TRANSFORMATIONS(MATHEMATICS), DATA PROCESSING, MATRICES(MATHEMATICS), INTEGRAL TRANSFORMS, REAL TIME, THESES.
Subject Categories : Cybernetics
Distribution Statement : APPROVED FOR PUBLIC RELEASE