An Overview of OCR Recognition Modules for the LEADTOOLS OCR Module - OmniPage Engine

LEADTOOLS provides fast and highly accurate Optical Character Recognition SDK technology for .NET (C# & VB), C/C++, iOS, macOS, Java, and web. The following sections describe this capability in more detail.

Automatic recognition module

NativeOcrZoneRecognitionModule.Auto

Specifies that the Engine will try to automatically select the most suitable recognition module for the zone. This is determined just before recognition, according to the zone's filling method and, if necessary, other settings, most typically the Character Set.

MTX OmniFont recognition module

NativeOcrZoneRecognitionModule.OmniFontMText

This recognition module recognizes machine-printed text; i.e. text from printed publications, laser or ink-jet printers and electric typewriters. Output from mechanical typewriters in good condition may also be acceptable. It should also be used for Letter or Near Letter Quality output from dot-matrix printers, and can also be used for Draft Quality.

Only images with the following resolution ranges are supported: 90-110, 160-240, 280-320, 400 and 600.

This module does not process images larger than 6600 pixels in either width or height. In other words, it can safely handle A3 size (11.69" x 16.54") (both portrait and landscape) images with 300 dpi resolution. At larger resolution the supported image size is smaller.

The module can handle a maximum of 64 zones defined on an image.

MOR multi-lingual OmniFont recognition module

NativeOcrZoneRecognitionModule.OmniFontMor

This module recognizes machine-printed text; i.e. text from printed publications, laser or ink-jet printers and electric typewriters. Output from mechanical typewriters in good condition may also be acceptable. It should also be used for Letter or Near Letter Quality (LQ, NLQ) output from dot-matrix printers. There are two ways of modifying incoming images to make them more suitable for the module:

This module can safely handle A3 size (11.69" x 16.54") (both portrait and landscape) images with 300 dpi resolution.

The module can handle a maximum of 500 zones defined on an image.

DOT Matrix (DOT 9-pin draft dot-matrix recognition module)

NativeOcrZoneRecognitionModule.DotMatrix

This module is designed for ONLY draft-quality 9-pin dot-matrix texts. For NLQ or LQ texts, the NativeOcrZoneRecognitionModule.OmniFontPlus2WayVoting, NativeOcrZoneRecognitionModule.OmniFontPlus3WayVoting, NativeOcrZoneRecognitionModule.OmniFontMText or NativeOcrZoneRecognitionModule.OmniFontMor modules give better results.

OMR optical mark recognition module

NativeOcrZoneRecognitionModule.Omr

LEADTOOLS OMR (Optical Mark Recognition) Module extends the functionality of LEADTOOLS SDKs by providing properties, methods, and events for easily incorporating fast, automated, and accurate optical mark recognition into your application. Optical Mark Recognition is used in surveys, polls, academic exams and official applications, to recognize the bubbles that the applicant fills in to indicate their selections. Supported marks include tick marks, X's, lines, checkmarks, and scribbles. Supported shapes (or frames) include boxes, circles and ellipses. For more information, refer to Using OMR in LEADTOOLS .NET OCR.

ICR hand-printed numeral recognition module

NativeOcrZoneRecognitionModule.IcrNumeral

This recognition module can be used for hand-printed numerals and four additional signs. If more hand-printed characters are to be recognized, use the NativeOcrZoneRecognitionModule.IcrCharacter recognition module.

ICR hand-printed recognition module

NativeOcrZoneRecognitionModule.IcrCharacter

This recognition module can be used for hand-printed characters. If only numerals need to be recognized, use the NativeOcrZoneRecognitionModule.IcrNumeral recognition module.

MAT matrix matching recognition module

NativeOcrZoneRecognitionModule.MatrixMatching

This module is designed to read certain groups of fixed-font characters specially designed for OCR or imaging applications, in which no two characters have similar shapes. Each character group has its own filling method. Application areas are in banking, check or waybill handling, product distribution and document validation, where high accuracy can be vital. It also handles some non-fixed print styles.

FRX multi-lingual OmniFont recognition module

NativeOcrZoneRecognitionModule.OmniFontFireWorx

This module recognizes machine-printed text; i.e. text from printed publications, laser or ink-jet printers and electric typewriters. Output from mechanical typewriters in good condition may also be acceptable. It should also be used for Letter or Near Letter Quality (LQ, NLQ) output from dot-matrix printers.

PLUS2WAY and PLUS3WAY Voting OmniFont recognition modules

NativeOcrZoneRecognitionModule.OmniFontPlus2WayVoting

NativeOcrZoneRecognitionModule.OmniFontPlus3WayVoting

These recognition modules recognize machine-printed text; i.e. text from printed publications, laser or ink-jet printers and electric typewriters. Output from mechanical typewriters in good condition may also be acceptable.

The PLUS2WAY and PLUS3WAY modules use voting technology to improve recognition results.

The PLUS2WAY voting module combines the results from the MOR and MTX modules.

The PLUS3WAY voting module combines the results from the MOR, MTX and FRX modules.

With either of these two voting modules, the accuracy is considerably better, but recognition may take significantly more time than any single module.

Note: The image handling algorithms for all modules of the OmniPage engine were designed to deal with practically unlimited image sizes: 32000 pixels in both directions.

Asian recognition module

NativeOcrZoneRecognitionModule.Asian

This module provides recognition services for four Asian languages with horizontal or vertical text direction; these languages are Japanese, Korean and Chinese - Traditional and Simplified. It can handle short embedded texts in English.

The Asian language handling differs somewhat from that for Western languages. Spell checking, editor display and verification are not available for Asian languages. Only one Asian language should be set for recognition and Western languages should not be set alongside an Asian language. However, the Asian OCR Engine can recognize short English texts embedded in Asian text, without English needing to be set. If embedded texts are in other Latin-alphabet languages, these similarly do not need to be set; however, accented characters may not always be handled correctly.

The following table shows the supported recognition modules for each OCR engine:

Recognition ModuleOmniPageLEADArabic
AutoYesYesYes
OmniFontMTextYesYesNo
OmniFontMorYesYesNo
DotMatrixYesYesNo
OmrYesYesYes
IcrNumeralYesYesNo
IcrCharacterYesYesNo
MatrixMatchingYesYesNo
OmniFontFireWorxYesYesNo
OmniFontPlus2WayVotingYesYesNo
OmniFontPlus3WayVotingYesYesNo
AsianYesYesNo

The following table shows the text recognition module support for each of the 119 languages in the LEADTOOLS OCR Module - OmniPage Engine/LEAD engine:

LanguageOmrOmniFontMTextOmniFontFireWorxOmniFontPlus2WayVotingOmniFontPlus3WayVotingDotMatrixIcr
AfrikaansYesNoYesYesYesYes CYes
AlbanianYesNoYesYesYesYes CYes
AymaraYesNoYesYesYesYesYes
BasqueYesNoYesYesYesNoYes
BembaYesYes ENNoYesYesYesYes
BlackfootYesYes ENNoYesYesYesYes
Brazilian BYes BYesYesYesYesYesYes
BretonYesNoYesYesYesYes CYes
BugotuYesYes ENNoYesYesYesYes
BulgarianYesNoYesYesYesNoNo
ByelorussiaYesNoYesYesYesNoNo
CatalanYesNoYesYesYesYes CYes
ChamorroYesNoNoYesYesYesYes
ChechenYesNoNoYesYesNoNo
CorsicanYesNoNoYesYesYesYes
CroatianYesNoYesYesYesNoYes
CrowYesYes ENNoYesYesYesYes
CzechYesNoYesYesYesNoYes
DanishYesYesYesYesYesYesYes
DutchYesYesYesYesYesYes CYes
EnglishYesYesYesYesYesYesYes
Eskimo (Inuit)YesNoYesYesYesNoYes
EsperantoYesNoNoYesYesNoNo
EstonianYesNoYesYesYesYesYes
FaroeseYesNoYesYesYesNoNo
FijianYesNoNoYesYesNoYes
FinnishYesYesYesYesYesYesYes
FrenchYesYesYesYesYesYes CYes
FrisianYesNoYesYesYesYes CYes
FriulianYesNoYesYesYesYes CYes
Gaelic (Irish)YesNoYesYesYesYesYes
Gaelic (Scottish)YesNoYesYesYesYes CYes
GalicianYesYesYesYesYesYesYes
GandaYesNoNoYesYesNoYes
GermanYesYesYesYesYesYesYes
GreekYesNoYesYesYesYesNo
GuaraniYesNoNoYesYesYes CYes
Hani YesYes ENNoYesYesYesYes
HawaiianYesYes ENYesYesYesYesYes
HungarianYesNoYesYesYesYesYes
IcelandicYesNoYesYesYesNoNo
IdoYesYes ENNoYesYesYesYes
IndonesianYesYes ENYesYesYesYesYes
InterlinguaYesYes ENNoYesYesYesYes
ItalianYesYesYesYesYesYes CYes
KabardianYesNoNoYesYesNoNo
KasubYesNoNoYesYesNoYes
Kawa YesYes ENNoYesYesYesYes
KikuyuYesNoNoYesYesNoNo
KongoYesYes ENNoYesYesYesYes
KpelleYesYes ENNoYesYesYesYes
Kurdish YesNoYesYesYesNoYes
Latin LYesYes LYesYesYesYes LYes
LatvianYesNoYesYesYesNoYes
LithuanianYesNoYesYesYesNoYes
LubaYesNoNoYesYesNoYes
LuxembourgianYesNoNoYesYesYes CYes
MacedonianYesNoYesYesYesNoNo
MalagasyYesYes EN/MNoYesYesYes CYes
MalayYesNoYesYesYesNoYes
MalinkeYesNoNoYesYesYes CYes
MalteseYesNoNoYesYesNoNo
MaoriYesYes ENNoYesYesYesYes
MayanYesNoNoYesYesYesYes
Miao YesYes ENNoYesYesYesYes
MinankabawYesNoNoYesYesNoYes
MohawkYesYes ENNoYesYesYesYes
MoldavianYesNoNoYesYesNoNo
NahuatlYesYes ENNoYesYesYesYes
NorwegianYesYesYesYesYesYesYes
NyanjaYesYes ENNoYesYesYesYes
OccidentalYesNoNoYesYesYesYes
OjibwayYesNoNoYesYesNoYes
PapiamentoYesNoNoYesYesYesYes
Pigin EnglishYesYes ENYesYesYesYesYes
PolishYesNoYesYesYesNoYes
PortugueseYesYesYesYesYesYes CYes
ProvençalYesNoNoYesYesYes CYes
QuechuaYesNoNoYesYesYesYes
RhaeticYesNoNoYesYesYes CYes
RomanianYesNoYesYesYesNoNo
RomanyYesNoNoYesYesNoYes
RuandaYesYes ENNoYesYesYesYes
RundiYesYes ENNoYesYesYesYes
RussianYesNoYesYesYesNoNo
SamiYesNoNoYesYesNoYes
Sami, LuleYesNoNoYesYesNoYes
Sami, NorthernYesNoNoYesYesNoYes
Sami, SouthernYesNoNoYesYesNoYes
SamoanYesNoNoYesYesYes CYes
SardinianYesNoNoYesYesYes CYes
SerbianYesNoYesYesYesNoNo
Serbian, LatinicYesNoYesYesYesNoYes
Shona SYesYes SNoYesYesYes SYes
SiouxYesYes ENNoYesYesYesYes
SlovakYesNoYesYesYesNoYes
SlovenianYesNoYesYesYesNoYes
SomaliYesYes ENNoYesYesYesYes
Sorbian (Wend)YesNoYesYesYesNoYes
SothoYesNoNoYesYesYesYes
SpanishYesYesYesYesYesYesYes
Sundanese SNYesNoNoYesYesYes SNYes SN
SwahiliYesYes ENYesYesYesYesYes
SwaziYesNoNoYesYesNoYes
SwedishYesYeYesYesYesYesYes
TagalogYesYes ENNoYesYesYesYes
TahitianYesNoYesYesYesYes CYes
TinpoYesYes ENNoYesYesYesYes
TonganYesYes ENNoYesYesYesYes
Tswana (Chuana)YesNoNoYesYesYes CYes
Tun *YesYes ENNoYesYesYesYes
TurkishYesNoYesYesYesNoYes T
UkrainianYesNoYesYesYesNoNo
VisayanYesYes ENNoYesYesYesYes
WelshYesNoYesYesYesYes WYes W
WolofYesNoNoYesYesYes CYes
XhosaYesYes ENNoYesYesYesYes
ZapotecYesYes ENNoYesYesYesYes
ZuluYesNoYesYesYesNoYes

* = This language can be handled only if it is written in the Latin alphabet.

B = Brazilian has a separate dictionary from Portuguese in the OmniFontMText and OmniFontFireWorx modules. Other modules treat Brazilian as Portuguese. Brazilian is available for language marking in the output document.

L = Latin is usually written without accented letters, but sometimes breves or macrons are placed over vowels. In these cases, the indicated modules do not provide support.

M = Some dialects of Malagasy are written without accents. In these cases, OmniFontMText provides support.

S = Shona may be written without accents, but sometimes uses acutes and graves on vowels. In these cases the indicated modules do not provide full support.

SN = Sundanese uses only one accented letter; sometimes this is E-breve, sometimes E-acute. The indicated modules support E-acute but not E-breve.

W = Welsh contains two rarely used characters: W-circumflex and Y-circumflex. These modules can handle Welsh with the exception of these two characters.

Footnotes on OmniFontMText:

The twelve selectable languages are those with Yes with no added footnote letter. For these languages this module uses its own language dictionaries.

EN = Languages denoted are thought to contain no accented letters. To read them, select English and disable spell checking from a main dictionary.

Footnotes on DotMatrix modules:

C = Not all uppercase letters are supported. See the module specification for a precise listing. This is probably not a serious restriction, since many 9-pin dot-matrix printers cannot print all the accented uppercase characters.

Footnotes on Icr modules:

T = The module cannot handle the lowercase dotless-i.

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