Accession Number : AD0676498

Title :   ON THE ACCURACY OF CALCULATING CORRELATION COEFFICIENTS BY THE OPTICAL METHOD (O TOCHNOSTI VYCHISLENIYA KOEFFITSIENTOV KORRELYATSII OPTICHESKIM SPOSOBOM),

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Eliseev,V. K.

Report Date : 20 OCT 1967

Pagination or Media Count : 16

Abstract : A theoretical study is presented of the effect of contrast of pictures being recognized and standard masks upon the accuracy of computation of correlation coefficients. It is assumed that contrast variations are caused by linear transformations, and that the relative error of measuring luminous fluxes is specified. Formulas are developed for evaluating the accuracy of optical calculation of correlation coefficients for any set of standards and for determining the effect of contrasts on this accuracy. This permits formulating specifications for the measuring optical correlators and the standard masks. Curves plotted on the basis of experiments with 'Moskva' typewriter texts permit carrying out all calculations connected with the recognition of this typewriter's characters. An example has shown that an instrument error of 1% and a contrast of 10 or better are required in order to ensure an error probability of 0.0001 for the hard, first and second carbon copies. The results of this study are claimed to be applicable to any automatic reader in which the error is calculated as a difference of signals of two measuring channels.

Descriptors :   (*READING MACHINES, *PATTERN RECOGNITION), CHARACTER RECOGNITION, AUTOMATION, TYPEWRITERS, SYMBOLS, CORRELATION TECHNIQUES, GRAPHICS, USSR

Subject Categories : Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE