1、BRITISH STANDARD BS5464-1: 1977 ISO1073-I: 1976 Specification for Optical character recognition Part1: Character set OCR-A Shapes and dimensions of the printed image ISO title: Alphanumeric character sets for optical recognition Part1: Character set OCR-A Shapes and dimensions of the printed image U
2、DC 681.327.12:681.3.04+003BS BS5464-1:1977 This BritishStandard, having been prepared under the directionof the Data ProcessingStandards Committee,was published underthe authority of the Executive Board on 29April1977 BSI05-2000 The following BSI references relate to the work on this standard: Commi
3、ttee reference DPS/14 Draft for comment75/73081 ISBN 0 580 09821 4 Cooperating organizations The Data Processing Standards Committee, under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scientific and industrial organiz
4、ations: British Airways British Computer Society* British Paper and Board Industry Federation* British Printing Industry Federation* Business Equipment Trade Association* Civil Service Department Central Computer Agency* Committee of London Clearing Bankers* Department of Industry Department of Indu
5、stry National Physical Laboratory* Department of the Environment Fire Research Station Electricity Supply Industry in England and Wales* Electronic Engineering Association* Engineering Equipment Users Association* Government Communication Headquarters HM Customs and Excise Institute of Cost and Mana
6、gement Accountants Institute of Municipal Treasurers and Accountants (Incorporated) Institution of Electrical and Electronics Technician Engineers Institution of Electrical Engineers Institution of Mechanical Engineers London Transport Executive Ministry of Defence National Coal Board* National Rese
7、arch Development Corporation Post Office* Society of British Aerospace Companies The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of
8、 this BritishStandard: Her Majestys Stationery Office PIRA Research Association for the Paper and Board Printing and Packaging Industries Production Engineering Research Association of Great Britain Amendments issued since publication Amd. No. Date of issue CommentsBS5464-1:1977 BSI 05-2000 i Conten
9、ts Page Cooperating organizations Inside front cover Foreword ii 1 General 1 2 Character set OCR-A 2 3 Character shapes and dimensions 3 4 Use of the table of values 4 5 Radii and corners 5 6 Relative vertical position of printed characters 6 7 Relative horizontal position of printed characters 6 Ta
10、ble 1 OCR-A printing frame dimensions 3 Table 2 Radii 4 Table 3 OCR-A values 5BS5464-1:1977 ii BSI 05-2000 Foreword This BritishStandard has been prepared under the authority of the Data Processing Standards Committee. It is identical with ISO1073-I “Alphanumeric character sets for optical recogniti
11、on Part1: Character set OCR-A Shapes and dimensions of the printed image”, which was prepared by subcommittee3, Character and mark recognition, of Technical Committee97, Computers and information processing. The UnitedKingdom is a participating member of both the subcommittee and the committee. Its
12、delegations appointed and briefed by the BritishStandards Institution Technical Committee DPS/14, Character and mark recognition, were involved in preparing this standard. Part2 is identical with ISO/1073-II, and deals with the character set OCR-B. Part3 deals with the encoding of character sets OCR
13、-A and OCR-B. Terminology and conventions. The text of the International Standard has been accepted as suitable for publication, without deviation, as a BritishStandard. Certain terminology and conventions are used, however, that are not identical with those used in BritishStandards. Attention is th
14、erefore drawn to the following. Wherever the words “International Standard”, relating to this publication, appear, they should be interpreted as “BritishStandard”. Except in the case of imperial equivalents, the comma has been used throughout as a decimal marker. In BritishStandards it is current pr
15、actice to use a full point (a full stop on the baseline) as a decimal marker. Cross reference (See1.3.1 and1.3.2.) BS4730 “The UnitedKingdom7-bit data code (ISO-7-UK)” is the UK national version of ISO646 “7-bit coded character set for information processing interchange”. It is based on and is fully
16、 in conformity with ISO646 but exercises some of the possible variations and options in a national sense. Textual error. Attention is drawn to the inconsistent use of symbols for dimensions. In the text and tables on pages1 to5 the correct italic (sloping) type has been used (in accordance with ISO3
17、1-0) but in the drawings (pages7 to26) dimensions have been represented by roman (upright) type. This has been notified to ISO Central Secretariat and when an amendment is issued to the International Standard this standard will be likewise amended. A British Standard does not purport to include all
18、the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii,
19、 pages1 to27 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5464-1:1977 BSI 05-2000 1 1 General 1.1 Scope This International Standard for character shapes and si
20、zes is intended to facilitate and foster the use of Optical Character Recognition (OCR) in data processing, by defining character shapes suitable for both human and machine reading. It establishes a common basis for printing equipment and optical scanning equipment for OCR interchange applications.
21、Additional International Standards will cover the print quality and the relevant characteristics of the formats needed to satisfy interchange requirements. 1.2 Field of application This International Standard specifies the printed image shapes and sizes of alphanumeric characters, graphics and symbo
22、ls designed for use in Optical Character Recognition. They are also suitable for general purposes. In order to satisfy present requirements and encourage the wide extension of OCR applications, two sets of characters are specified. These are named OCR-A and OCR-B. Character set OCR-A includes the nu
23、meric sub-set which was recommended in draft ISO Recommendation No.890 (now part of this International Standard). The shapes of the characters have been designed to be suitable for use in many applications of OCR. Dimensions of OCR-A are given in three sizes. The shapes of the OCR-B characters have
24、been designed for use in OCR systems without undue sacrifice of their suitability for general purposes in a wide range of applications. Dimensions of OCR-B are given in three sizes. (Seepart II.) 1.3 Definitions For the purpose of this International Standard the following definitions apply: 1.3.1 OC
25、R-A a repertoire of69 characters of which56 are graphics included in the ISO7-bit coded character set (ISO646:1973). It comprises digits, capital letters, capital national letters and other graphics 1.3.2 OCR-B a repertoire of121 characters comprising digits, capital and small letters, all the graph
26、ics specified in the ISO7-bit coded character set (ISO646:1973), national letters, diacritical signs and further graphics (Seepart II.) 1.3.3 printing frame the smallest rectangle the sides of which are horizontal and vertical and which includes the centreline shapes of all characters with the excep
27、tion of long vertical mark 1.3.4 sizes of a repertoire the sizes specified by the height H and the width W of the relevant printing frame NOTE 1Three sets of sizes are specified in order to permit the use of the OCR character sets with a wide range of printing equipment with different print quality
28、characteristics. Devices such as typewriters, cash registers, numbering machines, high-speed printers, credit card imprinters and non-impact imprinters, and printing processes such as letterpress and offset, are all involved. NOTE 2For applications which involve circulation of documents across bound
29、aries between areas in which different national characters are in use, agreement between the sender and the recipient of the documents is required. NOTE 3The metric and inch dimensions in this International Standard are rounded and therefore consistent but not exactly equal. Either system may be use
30、d but the two should not be intermixed. NOTE 4It is recognized that some type-making and printing processes will not be able to produce sharp corners. Corners not specified as having a specific radius should be as sharp as practicable. However, it is not necessary for OCR purposes that the radii of
31、the corners of the nominal printed image be less than0,08mm (0.0035in). NOTE 5All OCR-A characters are designed to be free-standing individual characters, and therefore are not intended for dual use with (or as) diacritical marks in OCR applications.BS5464-1:1977 2 BSI 05-2000 2 Character set OCR-A
32、2.1 Name The name of the character set is OCR-A. 2.2 OCR-A sizes Table 1 below specifies the dimensions of the printing frame (W,H) of the total repertoire in three sizes. It also indicates the nominal strokewidth T and the minimum length L of the long vertical mark (14H/9). The maximum length of th
33、e vertical mark is not specified as there is no intention of restricting it. 2.3 OCR-A repertoire 2.3.1 The69 characters of the OCR-A repertoire are as follows (seealso2.5): 10digits 0 to9 26 capital letters A to Z 17 graphics Space (non-printing character)Semi-colon / Solidus 7 capital national let
34、ters 3 currency symbols $ Dollar sign Pound sign Yen sign 3 abstract symbols Hook Fork Chair 1 long vertical mark | 2 erase characters Character Erase Group EraseBS5464-1:1977 BSI 05-2000 3 2.3.2 The14characters comprising the OCR-A numeric sub-set are the following: 2.4 Use of characters 2.4.1 Lett
35、er Y and symbol fork It is recommended that the letter Y and the abstract symbol for forkshould not both be used in the same application. 2.4.2 OCR-A numeric sub-set For applications requiring numeric reading only, it is suggested that the numeric sub-set (see2.3.2) be used. 2.5 Alternative shapes t
36、wo shapes are shown. The first shape is indicated as the preferred one and should generally be the one used. However, some particular applications may require the use of the standard alternative shape shown. 3 Character shapes and dimensions The character shapes and dimensions are specified by the d
37、rawings given on pages7 to26 and by the table of values on page5. The nominal printed image of each character is specified by its centreline and by its nominal strokewidth. Table 1 OCR-A printing frame dimensions 10digits 0 to9 3 abstract symbols Hook Fork Chair 1 long vertical mark | For the charac
38、ters Apostrophe Comma Full stop Hyphen Question mark Size millimetres inches W H T L W H T L I 1,40 2,40 0,35 3,7 0.055 0.094 0.014 0.146 III 1,52 3,20 0,38 5,0 0.060 0.126 0.015 0.196 IV 2,04 3,80 0,51 5,9 0.080 0.150 0.020 0.233BS5464-1:1977 4 BSI 05-2000 4 Use of the table of values (Table 3) 4.1
39、 Table 3 specifies in both millimetres and inches the dimensions for each character in each of the three sizes I, III and IV. 4.2 Table 3 lists character height, width and stroke dimensions based on the height H of the printing frame, the width W of the printing frame, the nominal strokewidth T. 4.3
40、 Table 3 also lists, as items r 1to r 6 , the values of the centreline radii specified for use in the characters listed in Table 2. The formulae for calculation of r 1to r 6are given on page6. Table 2 Radii Character Radius O and r 1 r 2 Q r 3 S r 4 r 5 r 6BS5464-1:1977 BSI 05-2000 5 5 Radii and cor
41、ners All radii specified for the OCR-A characters are given on the drawings and in Table 3. All edges should be blended, with rounded corners. Table 3 OCR-A values millimetres inches I III IV I III IV H W T 1/2T 3/2T 2 T 1/8W 1/4W 3/8W 7/16W 1/2W 9/16W 5/8W 3/4W 1/16H 1/8H 3/16H 1/4H 9/32H 5/16H 3/8
42、H 7/16H 1/2H 17/32H 9/16H 5/8H 11/16H 3/4H 13/16H 7/8H 15/16H r 1 r 2 r 3 r 4 r 5 r 6 L 2,400 1,400 0,350 0,175 0,525 0,700 0,175 0,350 0,525 0,612 0,700 0,788 0,875 1,050 0,150 0,300 0,450 0,600 0,675 0,750 0,900 1,050 1,200 1,275 1,350 1,500 1,650 1,800 1,950 2,100 2,250 0,635 0,283 0,255 0,223 0,
43、476 0,336 3,7 3,200 1,520 0,380 0,190 0,570 0,760 0,190 0,380 0,570 0,665 0,760 0,855 0,950 1,140 0,200 0,400 0,600 0,800 0,900 1,000 1,200 1,400 1,600 1,700 1,800 2,000 2,200 2,400 2,600 2,800 3,000 1,022 0,283 0,266 0,310 0,755 0,327 5,0 3,800 2,040 0,510 0,255 0,765 1,020 0,255 0,510 0,765 0,892
44、1,020 1,148 1,275 1,530 0,238 0,475 0,713 0,950 1,069 1,188 1,425 1,663 1,900 2,019 2,138 2,375 2,613 2,850 3,088 3,325 3,563 1,084 0,398 0,366 0,360 0,807 0,468 5,9 0.0940 0.0550 0.0140 0.0070 0.0210 0.0280 0.0069 0.0138 0.0206 0.0241 0.0275 0.0309 0.0344 0.0413 0.0059 0.0118 0.0176 0.0235 0.0264 0
45、.0294 0.0353 0.0411 0.0470 0.0499 0.0529 0.0588 0.0646 0.0705 0.0764 0.0823 0.0881 0.0248 0.0111 0.0100 0.0087 0.0186 0.0132 0.146 0.1260 0.0600 0.0150 0.0075 0.0225 0.0300 0.0075 0.0150 0.0225 0.0263 0.0300 0.0338 0.0375 0.0450 0.0079 0.0158 0.0236 0.0315 0.0354 0.0394 0.0473 0.0551 0.0630 0.0669 0
46、.0709 0.0788 0.0866 0.0945 0.1024 0.1103 0.1181 0.0401 0.0112 0.0105 0.0122 0.0297 0.0129 0.196 0.1500 0.0800 0.0200 0.0100 0.0300 0.0400 0.0100 0.0200 0.0300 0.0350 0.0400 0.0450 0.0500 0.0600 0.0094 0.0188 0.0281 0.0375 0.0422 0.0469 0.0563 0.0656 0.0750 0.0797 0.0844 0.0938 0.1031 0.1125 0.1219 0
47、.1313 0.1406 0.0431 0.0156 0.0143 0.0142 0.0320 0.0183 0.233BS5464-1:1977 6 BSI 05-2000 Formulae for centreline radii r 1to r 66 Relative vertical position of printed characters 6.1 Base line The base line is a horizontal line used to specify the nominal vertical position of characters printed in th
48、e same line of text. The position of the base line is indicated on the drawings of all characters (except for the long vertical mark). 6.2 Base line displacement The base line displacement, Y, of each character is the shortest distance between the base line and the centreline of that character. This
49、 value is indicated on the drawings of all characters for which it is not zero. 6.3 Vertical position The nominal vertical position of characters printed in the same line of text is such that the base lines of all characters should be aligned. 7 Relative horizontal position of printed characters 7.1 Reference line for the horizontal location of any character The horizontal location reference line of a character is perpendicular to the base line and divides the printing frame of that character equally. This line is indicated on each drawin
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