OCR-A


OCR-A is a font that arose in the early days of computer optical character recognition when there was a need for a font that could be recognized not only by the computers of that day, but also by humans. OCR-A uses simple, thick strokes to form recognizable characters.
The font is monospaced, with the printer required to place glyphs cm apart, and the reader required to accept any spacing between cm and cm.

Standardization

The OCR-A font was standardized by the American National Standards Institute
as ANSI X3.17-1981. X3.4 has since become the INCITS and the OCR-A standard is now called ISO 1073-1:1976. There is also a German standard for OCR-A called DIN 66008.

Implementations

In 1968, American Type Founders produced OCR-A, one of the first optical character recognition typefaces to meet the criteria set by the U.S. Bureau of Standards. The design is simple so that it can be easily read by a machine, but it is more difficult for the human eye to read.
As metal type gave way to computer-based typesetting, Tor Lillqvist used Metafont to describe the OCR-A font. That definition was subsequently improved by Richard B. Wales. Their work is available from CTAN.
To make the free version of the font more accessible to users of Microsoft Windows, John Sauter converted the Metafont definitions to TrueType using potrace and FontForge in 2004. In 2007, Gürkan Sengün created a Debian package from this implementation. In 2008. Luc Devroye corrected the vertical positioning in John Sauter's implementation, and fixed the name of lower case z.
Independently, Matthew Skala used mftrace to convert the Metafont definitions to TrueType format in 2006. In 2011 he released a new version created by rewriting the Metafont definitions to work with METATYPE1, generating outlines directly without an intermediate tracing step. On September 27, 2012, he updated his implementation to version 0.2.
In addition to these free implementations of OCR-A, there are also implementations sold by several vendors.

Use

Although optical character recognition technology has advanced to the point where such simple fonts are no longer necessary, the OCR-A font has remained in use. Its usage remains widespread in the encoding of cheques around the world. Some lock box companies still insist that the account number and amount owed on a bill return form be printed in OCR-A. Also, because of its unusual look, it is sometimes used in advertising and display graphics.
Notably, it is used for the subtitles in the television series Blacklist and for the main titles in The Pretender. Additionally, OCR-A is used for the film .
OCR-A is also the official font of Jocko Willink.

Code points

A font is a set of character shapes, or glyphs. For a computer to use a font, each glyph must be assigned a code point in a character set. When OCR-A was being standardized the usual character coding was the American Standard Code for Information Interchange or ASCII. Not all of the glyphs of OCR-A fit into ASCII, and for five of the characters there were alternate glyphs, which might have suggested the need for a second font. However, for convenience and efficiency all of the glyphs were expected to be accessible in a single font using ASCII coding, with the additional characters placed at coding points that would otherwise have been unused.
The modern descendant of ASCII is Unicode, also known as ISO 10646. Unicode contains ASCII and has special provisions for OCR characters, so some implementations of OCR-A have looked to Unicode for
guidance on character code assignments.

Pre-Unicode standard representation

The ISO standard ISO 2033:1983, and the corresponding Japanese Industrial Standard JIS X 9010:1984, define character encodings for OCR-A, OCR-B and E-13B. For OCR-A, they define a modified 7-bit ASCII set including only uppercase letters, digits, a subset of the punctuation and symbols, and some additional symbols. Codes which are redefined relative to ASCII, as opposed to simply omitted, are listed below:
CharacterImageLocationIn ASCIIComments
£0x23#Matches BS 4730, the United Kingdom variant of ISO 646.
0x29)Character name is still "RIGHT PARENTHESIS", despite showing a brace. Usual right brace ASCII code 0x7D is omitted.
0x3C<
0x3E>
¥0x5C\Matches JIS X 0201. Included in JIS X 9010, but omitted by ISO 2033.
0x5D]

Additionally, the long vertical mark is encoded at 0x7C, corresponding to the ASCII vertical bar.

Dedicated OCR-A characters in Unicode

The following characters have been defined for control purposes and are now in the "Optical Character Recognition" Unicode range 2440–245F:
NameImageTextUnicode
OCR HookU+2440
OCR ChairU+2441
OCR ForkU+2442
OCR Inverted fork'U+2443
OCR Belt buckle'U+2444
OCR Bow tieU+2445

Space, digits, and unaccented letters

All implementations of OCR-A use U+0020 for space,
U+0030 through U+0039 for the decimal digits,
U+0041 through U+005A for the unaccented upper case letters, and
U+0061 through U+007A for the unaccented lower case letters.

Regular characters

In addition to the digits and unaccented letters, many of the characters of OCR-A have obvious code points in ASCII.
Of those that do not, most, including all of OCR-A's accented letters, have obvious code points in Unicode.
NameGlyphUnicode
Exclamation MarkU+0021
Quotation MarkU+0022
Number SignU+0023
Dollar SignU+0024
Percent SignU+0025
AmpersandU+0026
ApostropheU+0027
Left ParenthesisU+0028
Right ParenthesisU+0029
AsteriskU+002A
Plus SignU+002B
CommaU+002C
Hyphen-MinusU+002D
Full Stop U+002E
Solidus U+002F
ColonU+003A
SemicolonU+003B
Less-Than SignU+003C
Equals SignU+003D
Greater-Than SignU+003E
Question MarkU+003F
Commercial AtU+0040
Left Square BracketU+005B
Reverse Solidus U+005C
Right Square BracketU+005D
Circumflex AccentU+005E
Left Curly BracketU+007B
Right Curly BracketU+007D
Pound Sign U+00A3
Yen SignU+00A5
Latin Capital Letter A with DieresisU+00C4
Latin Capital Letter A with Ring AboveU+00C5
Latin Capital Letter AEU+00C6
Latin Capital Letter N with TildeU+00D1
Latin Capital Letter O with DieresisU+00D6
Latin Capital Letter O with StrokeU+00D8
Latin Capital Letter U with DieresisU+00DC

Remaining characters

Linotype coded the remaining characters of OCR-A as follows:
NameGlyphUnicodeUnicode Name
Long Vertical MarkU+007CVertical Line
Alternate CommaU+E000private use 0
Character EraseU+E001private use 1
Alternate HyphenU+E003private use 3
Alternate PeriodU+E004private use 4
Alternate Question MarkU+E005private use 5
Alternate ApostropheU+E006private use 6

Additional characters

The fonts that descend from the work of Tor Lillqvist and Richard B. Wales define four characters not in OCR-A to fill out the ASCII character set. These shapes use the same style as the OCR-A character shapes. They are:
NameGlyphUnicode
Low LineU+005F
Grave AccentU+0060
Vertical LineU+007C
TildeU+007E

Linotype also defines additional characters.

Exceptions

Some implementations do not use the above code point assignments for some characters.

PrecisionID

The PrecisionID implementation of OCR-A has the following non-standard code points:
The Barcodesoft implementation of OCR-A has the following non-standard code points:
The Morovia implementation of OCR-A has the following non-standard code points:
The IDAutomation implementation of OCR-A has the following non-standard code points:

Sellers of font standards