1831 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEXAYHAPOAHAA OPTAHW3AUMR HO CTAHAAPTM3AUWM-ORGANISATION INTERNATIONALE DE NORMALISATION Printing specifications for optical character recognition Spécifications d'impression des caracteres pour reconnaissance optique First edition - 1980-10-15 ISO 1831-1980 (E) UDC 681.327.5.048 Ref. No. ISO 1831-1980 (E) Descriptors : data processing, printing, optical characters, character recognition, optical recognition, printing papers, specifications, dimensions, legibility, measurement. Pricebasedon42pages Foreword national standards institutes (Iso member bodies). The work of developing Inter- national Standards is carried out through ISo technical committees. Every member bodyinterested inasubjectforwhichatechnical committeehas been set uphasthe right to be represented 'on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. International Standard ISO 1831 was developed by Technical Committee ISO/TC 97, Computers and information processing, and was circulated to the member bodies in January1979. Australia Ireland Romania Belgium Italy South Africa, Rep. of Czechoslovakia Japan Spain Finland Mexico Sweden France Netherlands Switzerland Germany, F.R. Poland USSR The member bodies of the following countries expressed disapproval of the document on technical grounds : Canada United Kingdom USA This International Standard cancels and replaces ISO Recommendation R 1831-1971, of whichitconstitutesatechnicalrevision. International Organization for Standardization, 1980 Printed in Switzerland ii Contents Page o Introductio 0.1 InterpretationoftheInternationalStandard. 0.2 Use of the International Standard 1. Scopeandfieldofapplication Reference 3 Spectral requirements 3.1 General 2 3.2 Spectral bands 2 Paper specifications for OCR. 4.1 General .. 2 4.2 Luminous reflectance factor R。of paper 2 4.3 Dirt in paper.. 4.4 Paperopacity 4.5 Variation in reflectance of paper. 5 Characteristics of the printed image . 5.1 General 5.2 Print quality tolerance range 5.3 Definitionofcharacteroutlinelimits 5.4Measurementsofparameter Characterpositioning 19 6.1 General 19 6.2 Documentreferenceedges 19 6.3 Character boundary 19 6.4 Characterskew 20 !!!!