ANSI INCITS 99-1983 Information Systems - Optical Character Recognition (OCR)- Guidelines for OCR Print Quality.pdf

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1、ADOPTED FOR USE BYTHE FEDERAL GOVERNMENTSEE NOTICE ON INSIDEANSI INCITS 99-1983 (R2002)(formerly ANSI X3.99-1983 (R1997) for Information Systems -Optical Character Recognition (OCR)-Guidelines for OCR Print QualityPUB 90This guideline has been adopted for Federal Government use. Details concerning i

2、ts use within the Federal Government are contained in Federal Information Processing Standards Publication 90, Guideline for Optical Character Recognition (OCR) Print Quality. For a complete list of the publications available in the Federal Information Processing Standards Series, write to the Stand

3、ards Processing Coordinator (ADP), Institute for Computer Sciences and Technology, National Bureau of Standards, Washington, D.C. 20234. ANSI X3.99-l 983 American National Standard for Information Systems - Optical Character Recognition (OCR)- Guidelines for OCR Print Quality Secretariat Computer an

4、d Business Equipment Manufacturers Association Approved July 1, 1983 American National Standards Institute, Inc AmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by t

5、he standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus requi

6、res that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketin

7、g, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or authority to

8、 issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard may be

9、 revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the Am

10、erican National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1983 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval sys

11、tem or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaForeword (This Foreword is not a part of ANSI X3 99-1983 ) These guidelines are supplemented by other OCR documents for character shapes, char- acter positioning,

12、inks, papers, and forms design. The material contained in these guidelines originally appeared in American National Stan- dard Character Set and Print Quality for Optical Character Recognition (OCR-A), ANSI X3.17-1977 In 1981, ANSI X3.17-1977 was revised and became a standard for OCR-A character sha

13、pes and size only (American National Standard Character Set for Optical Character Recognition (OCR-A), ANSI X3 .17-l 98 1). The print quality information that was deleted in the revision is now provided in these guidelines. No new quality require- ments have been added. This document, while based on

14、 OCR-A and OCR-B, can serve as a print quality guide- line for other constant-stroke-width machine-readable fonts. The terms, uppercase and lowercase, are widely used and accepted in the United States and have been used in these guidelines in place of the International Standards Organiza- tion terms

15、, letter and small letter In this document, these terms have the same meaning and can be used interchangeably. Suggestions for improvement of this standard will be welcome. They should be sent to the Computer and Business Equipment Manufacturers Association, 311 First Street, NW, Suite 500, Washingt

16、on, D.C. 20001. This standard was processed and approved for submittal to ANSI by American National Standards Committee on Information Processing Systems, X3. Committee approval of the standard does not necessarily imply that aII committee members voted for its approval. At the time it approved this

17、 standard, the X3 Committee had the following members: Edward Lohse, Chair Catherine A. Kachurik, Administrative Secretary Organization Represented Name of Representative American Bankers Association . . . . . . . . . . . . . . . . . . . . . . . . . . .Cynthia Fuller Chris Crawford (Alt) American Ex

18、press Company. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .R. S. Newman R. G. Wilson (AR) American Library Association. . . . . . . . . . . . . . . . . . . . . . . . . . . . .Paul Peters American Nuclear Society . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . .Geraldine C. M

19、ain D. R. Vondy (AR) AMP Incorporated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Patrick E. Lannan C. Brill (Alt) Association for Computing Machinery . . . . . . . . . . . . . . . . . . . . . . . .J. A. N. Lee Pat Skelly (Alt) Association of American Railroads. . . . . . .

20、. . . . . . . . . . . . . . . . . . .R. A. Petrash Association of Computer Users . . . . . . . . . . . . . . . . . . . . . . . . . . . .Hillel Segal Thomas Kurihara (AR) Association of the Institute for Certification of Computer Professionals. . . _ .Thomas Kurihara Ardyn E. Dubnow (Alt) Burroughs C

21、orporation. . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . .Ira R. Purchis Jerrold S. Foley (Alt) Control Data Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Charles E. Cooner Keith Lucke (Ah) Data General Corporation . . . . . . . . . . . . . . . . . . . . .

22、 . . . . . . . . . .Steven W. Weingart Data Processing Management Association . . . . . . . . . . . . . . . . . . . Howell A. Richards (Alt) . .Ardyn E. Dubnow Joseph A. Federici (Alt) Digital Equipment Computer Users Society . . . . . . . . . . . . . . . . . . . . .James Hodges Digital Equipment Co

23、rporation . . . . . . . , . . John R. Barr (Aft) . . . . . . . . . . . . . . . . .Lois C. Frampton Gary S. Robinson (Alt) Exxon Office Systems . . . . . . . . . . . . . . . . . . . . . . . . . . _ . _ . _ .Robert Greenblatt Richard Joyce (Alt) Organization Represented General Services Administration

24、 . GUIDE International. . Harris Corporation Hewlett-Packard. . Honeywell Information Systems . IBM Corporation . IEEE Communications Society . 1EEE Computer Society . Lawrence Berkeley Laboratory Life Office Management Association . Moore Business Forms, Inc National Bureau of Standards. National C

25、ommunications System . NCR Corporation. i . Perkin-Elmer. . Prime Computer. . Professional Secretaries International. . Recognition Technology Users Association . SHARE,Inc Sperry Univac. Telephone Group. Texas Instruments, Inc. . 3MCompany . Travelers insurance Company, Inc . U.S. Department of Def

26、ense. Wang Laboratories, Inc. . Xerox Corporation Name of Representative .William C. Rinehuls Donald J. Page (Alt) .Frank Kirshenbaum Leland Milligan (Alt) .Sam Mathan David Abmayr (Alt) .Donald C. Loughry .Thomas J. McNamara David M. Taylor (Alt) .Mary Anne Gray 1. S. Wilson (Al0 .Thomas A. Vareton

27、i .Robert Poston Robert S. Stewart (Alt) .James A. Baker Robert J. Harvey (Alt) .James 1. Merrick James F. Foley, Jr (Alt) .Delmer H. Oddy .Robert E. Rountree James H. Burrows (Alt) .Marshall L. Cain George W. White (Alt) .Thomas W. Kern William E. Snyder (AIt) .David Luckowicz James Pisarcik (Alt)

28、.Richard Kramer Winfried A. Burke (Alt) .Jerome Heitman .Herbert F. Schantz G. W. Wetzel (Ah) .Thomas B. Steel Daniel Schuster (Alt) .Marvin W. Bass Charles D. Card (Alt) .Henry L. Marchese Stuart H. Garland (Alt) Alvro E. Herron (Alt) .Presley Smith Richard Trow, Jr (Alt) .R. C. Smith .Joseph T. Br

29、ophy .William LaPlant Belkis Leong-Hong (Alt) .Carl W. Schwartz Marsha Hayek (Alt) .John L. Wheeler Arthur R. Machell (Alt) Subcommittee X3Al on Optical Character Recognition, which developed these guide- lines, had the following members: T. C. Bagg, Chair R. Monell, Vice-Chair C. P. Newman, Secreta

30、ry C. Biss G. Korzeniewski R. Bloss J. McDonnell G. Brown S. McIntosh F. Cicha R. Mestler J. L. Crawford J. Miller B. Daniels D. Newton W. Davidson D. Oddy J. DeSautels T. Pealler W. Foster L. Richards D. Gibson H. Schantz K. Godwin N. Selke J. Hopkins E. Thompson R. Ireland P. Traglia T. Janning N.

31、 Weiland C. Knoedel J. Wells The X3A1 Working Group 3 on Print Quality, which had technical responsibility for the development of these guidelines, had the following members: T. Bagg, Chair K. Bye J. Crawford B. Frost D. Gibson S. Hou R. Ireland G. Martin J. McDonnell R. Mestler J. Miller D. Newton

32、T. Pealler D. Rosenberg E. Thompson N. Weiland Other persons who made technical contributions are: R. Green M. Hirsch M. Hogan A. Holt H. Schantz P. Traglia Special thanks is given to Mrs. Candice Leatherman of the National Bureau of Standards for the preparation of the innumerable drafts for this m

33、anuscript. Contents SECTION PAGE 1. Scope, Purpose, and Application . , 7 1.1 Scope . 7 1.2 Purpose. . 7 1.3 Application . 7 2. Related Standards. f 7 2.1 American National Standards . . . . . . 7 2.2 Other Publications. . . . . . . . 7 3. Definitions and Characteristics of the Printed Image . . . .

34、 . . 7 3.1 General. . . . . . . 7 3.2 Print Quality Parameters and Tolerance Ranges. . . . . . . 8 3.3 Definitions. . . . . . . 8 3.4 Spectral Requirements for Measurement of PCS . . . . . .13 4. Measurement of Character Geometry . . . . . . . . 15 4.1 General. . . . . . . . . 15 4.2 Determination o

35、f Stroke Edges . . . . . . . . . 15 4.3 Determination of Character Geometry for Print Quality Ranges. . . . . . . . . . 16 5. Measurement of Inking Quality .16 5.1 General . .I6 5.2 Contrast Variation Ratio (CVR) of a Character. .17 5.3 Voids.l7 5.4 spots .17 6. Approximate Methods of Visually Evalu

36、ating Print Quality. . .17 6.1 General. .17 6.2 Visual Determination of Character Outline Limit . .I7 6.3 Visual Identification of Allowable Voids . .17 6.4 Visual Identification of Allowable Spots . .18 6.5 Other Approximate Methods of Evaluation . .I8 Tables Table 1 Nominal Character Sizes and Str

37、oke-Width Tolerances 15 Table 2 PCS and CVR Values for Printed Characters .17 Figures Figure 1 Illustration of Reflectance,R, and R, 9 Figure 2 COL Cage. . .lO Figure 3 Character Stroke Degradation and the Resulting Test Device Signal .12 Figure 4 Physical Void and Spot Violation in Terms of Scan Si

38、gnal .13 Figure 5 Measured PCSv,td, PCS,i, and PCS, for x, y, and z Ranges from the Same Stroke. . .14 Figure 6 PCS,r,t forx.y.andzRangePrinting . .14 Figure 7 Enlarged View of Stroke Variation. . .16 Figure 8 Voids. .19 Figure 9 Spots . 20 American National Standard for Information Systems - Optica

39、l Character Recognition (OCR) - Guidelines for OCR Print Quality 1. Scope, Purpose, and Application 1.1 Scope. These guidelines describe the print quality parameters and measuring techniques for determining the quality of machine-printed characters to maximize the likelihood that they can be read by

40、 electro-optical means. 1.2 Purpose. The purpose of these guidelines is to es- tablish procedures for determining suitability of machine-printed characters to be read optically. 1.3 Application. Because of the variety of OCR appli- cations, these guidelines may not include all of the necessary print

41、 quality specifications or considerations for successful OCR reading. Items such as size of char- acter set, document size, mechanical properties of the paper, and format details should be resolved by con- sultation between users, suppliers, and OCR manufac- turers. Although each parameter may be in

42、dependently specified, reading performance may deteriorate if the limits of two or more parameters are approached simul- taneously. Every effort should be made to keep well within the limits. It is recognized, however, that in bulk printing from any device, the limits will oc- casionally and randoml

43、y be exceeded. 2. Related Standards 2.1 American National Standards. These guidelines are intended to be used in conjunction with the follow- ing American National Standards: ANSI X3.1 7-1981, Character Set for Optical Character Recognition (OCR-A) ANSI X3.49-1975 (R1982) Character Set for Optical C

44、haracter Recognition (OCR-B) ANSI X3.62-1979, Paper Used in Optical Character Recognition (OCR) Systems ANSI X3.86-1980, Optical Character Recognition (OCR) Inks ANSI X3.93M-1981, Optical Character Recognition (OCR) Character Positioning 2.2 Other Publications. These guidelines are intended to be us

45、ed in conjunction with the following publica- tions: ASTM E 308.66 (198 I), Standard Practice for Spectro- photometry and Description of Color in CIE 1931 Sys- tem ASTM F 149-76 (1980), Standard Definitions of Terms Relating to Optical Character Recognition X3/TR-S-82, Design of Optical Character Re

46、cognition Forms (Technical Report)2 3. Definitions and Characteristics of the Printed Image 3.1 General. The performance of OCR systems de- pends to a large extent on the optical and dimensional properties of the printed image. For machine recogni- tion of printed information, the paper shall provid

47、e high reflectance and printed images shall be sufficient- ly low reflectance to provide adequate contrast in the spectral range of interest. All printed devices are not capable of producing images to the same tolerance ranges, and all readers are not capable of reliably recognizing characters in al

48、l tol- erance ranges. In general, the performance level of an OCR reader will depend upon the number of characters to be recognized and the ability of the reader to tol- erate a range of stroke widths, contrasts, voids, spots, and character position variations. Considering these factors, three range

49、s of print quality have been defined in 3.2. They describe the wide ranges of printing pro- duced by various devices and processes and aid in Available from ASTM, 1916 Race Street, Philadelphia, PA 19103. Available from the Computer and Business Equipment Manu- facturers Association, 311 First Street, NW, Suite 500, Washing- ton, DC 20001. 7 AMERICANNATIONALSTANDARDX3 99-1983 classifying the capability of the associated reader. range places a lesser burden on the printing device and It should be emphasized that reliable recognition of a greater burden on the reading device. any sp