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 Module OmniPage LEAD Arabic
Auto Yes Yes Yes
OmniFontMText Yes Yes No
OmniFontMor Yes Yes No
DotMatrix Yes Yes No
Omr Yes Yes Yes
IcrNumeral Yes Yes No
IcrCharacter Yes Yes No
MatrixMatching Yes Yes No
OmniFontFireWorx Yes Yes No
OmniFontPlus2WayVoting Yes Yes No
OmniFontPlus3WayVoting Yes Yes No
Asian Yes Yes No

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

Language Omr OmniFontMText OmniFontFireWorx OmniFontPlus2WayVoting OmniFontPlus3WayVoting DotMatrix Icr
Afrikaans Yes No Yes Yes Yes Yes C Yes
Albanian Yes No Yes Yes Yes Yes C Yes
Aymara Yes No Yes Yes Yes Yes Yes
Basque Yes No Yes Yes Yes No Yes
Bemba Yes Yes EN No Yes Yes Yes Yes
Blackfoot Yes Yes EN No Yes Yes Yes Yes
Brazilian B Yes B Yes Yes Yes Yes Yes Yes
Breton Yes No Yes Yes Yes Yes C Yes
Bugotu Yes Yes EN No Yes Yes Yes Yes
Bulgarian Yes No Yes Yes Yes No No
Byelorussia Yes No Yes Yes Yes No No
Catalan Yes No Yes Yes Yes Yes C Yes
Chamorro Yes No No Yes Yes Yes Yes
Chechen Yes No No Yes Yes No No
Corsican Yes No No Yes Yes Yes Yes
Croatian Yes No Yes Yes Yes No Yes
Crow Yes Yes EN No Yes Yes Yes Yes
Czech Yes No Yes Yes Yes No Yes
Danish Yes Yes Yes Yes Yes Yes Yes
Dutch Yes Yes Yes Yes Yes Yes C Yes
English Yes Yes Yes Yes Yes Yes Yes
Eskimo (Inuit) Yes No Yes Yes Yes No Yes
Esperanto Yes No No Yes Yes No No
Estonian Yes No Yes Yes Yes Yes Yes
Faroese Yes No Yes Yes Yes No No
Fijian Yes No No Yes Yes No Yes
Finnish Yes Yes Yes Yes Yes Yes Yes
French Yes Yes Yes Yes Yes Yes C Yes
Frisian Yes No Yes Yes Yes Yes C Yes
Friulian Yes No Yes Yes Yes Yes C Yes
Gaelic (Irish) Yes No Yes Yes Yes Yes Yes
Gaelic (Scottish) Yes No Yes Yes Yes Yes C Yes
Galician Yes Yes Yes Yes Yes Yes Yes
Ganda Yes No No Yes Yes No Yes
German Yes Yes Yes Yes Yes Yes Yes
Greek Yes No Yes Yes Yes Yes No
Guarani Yes No No Yes Yes Yes C Yes
Hani Yes Yes EN No Yes Yes Yes Yes
Hawaiian Yes Yes EN Yes Yes Yes Yes Yes
Hungarian Yes No Yes Yes Yes Yes Yes
Icelandic Yes No Yes Yes Yes No No
Ido Yes Yes EN No Yes Yes Yes Yes
Indonesian Yes Yes EN Yes Yes Yes Yes Yes
Interlingua Yes Yes EN No Yes Yes Yes Yes
Italian Yes Yes Yes Yes Yes Yes C Yes
Kabardian Yes No No Yes Yes No No
Kasub Yes No No Yes Yes No Yes
Kawa Yes Yes EN No Yes Yes Yes Yes
Kikuyu Yes No No Yes Yes No No
Kongo Yes Yes EN No Yes Yes Yes Yes
Kpelle Yes Yes EN No Yes Yes Yes Yes
Kurdish Yes No Yes Yes Yes No Yes
Latin L Yes Yes L Yes Yes Yes Yes L Yes
Latvian Yes No Yes Yes Yes No Yes
Lithuanian Yes No Yes Yes Yes No Yes
Luba Yes No No Yes Yes No Yes
Luxembourgian Yes No No Yes Yes Yes C Yes
Macedonian Yes No Yes Yes Yes No No
Malagasy Yes Yes EN/M No Yes Yes Yes C Yes
Malay Yes No Yes Yes Yes No Yes
Malinke Yes No No Yes Yes Yes C Yes
Maltese Yes No No Yes Yes No No
Maori Yes Yes EN No Yes Yes Yes Yes
Mayan Yes No No Yes Yes Yes Yes
Miao Yes Yes EN No Yes Yes Yes Yes
Minankabaw Yes No No Yes Yes No Yes
Mohawk Yes Yes EN No Yes Yes Yes Yes
Moldavian Yes No No Yes Yes No No
Nahuatl Yes Yes EN No Yes Yes Yes Yes
Norwegian Yes Yes Yes Yes Yes Yes Yes
Nyanja Yes Yes EN No Yes Yes Yes Yes
Occidental Yes No No Yes Yes Yes Yes
Ojibway Yes No No Yes Yes No Yes
Papiamento Yes No No Yes Yes Yes Yes
Pigin English Yes Yes EN Yes Yes Yes Yes Yes
Polish Yes No Yes Yes Yes No Yes
Portuguese Yes Yes Yes Yes Yes Yes C Yes
Provençal Yes No No Yes Yes Yes C Yes
Quechua Yes No No Yes Yes Yes Yes
Rhaetic Yes No No Yes Yes Yes C Yes
Romanian Yes No Yes Yes Yes No No
Romany Yes No No Yes Yes No Yes
Ruanda Yes Yes EN No Yes Yes Yes Yes
Rundi Yes Yes EN No Yes Yes Yes Yes
Russian Yes No Yes Yes Yes No No
Sami Yes No No Yes Yes No Yes
Sami, Lule Yes No No Yes Yes No Yes
Sami, Northern Yes No No Yes Yes No Yes
Sami, Southern Yes No No Yes Yes No Yes
Samoan Yes No No Yes Yes Yes C Yes
Sardinian Yes No No Yes Yes Yes C Yes
Serbian Yes No Yes Yes Yes No No
Serbian, Latinic Yes No Yes Yes Yes No Yes
Shona S Yes Yes S No Yes Yes Yes S Yes
Sioux Yes Yes EN No Yes Yes Yes Yes
Slovak Yes No Yes Yes Yes No Yes
Slovenian Yes No Yes Yes Yes No Yes
Somali Yes Yes EN No Yes Yes Yes Yes
Sorbian (Wend) Yes No Yes Yes Yes No Yes
Sotho Yes No No Yes Yes Yes Yes
Spanish Yes Yes Yes Yes Yes Yes Yes
Sundanese SN Yes No No Yes Yes Yes SN Yes SN
Swahili Yes Yes EN Yes Yes Yes Yes Yes
Swazi Yes No No Yes Yes No Yes
Swedish Yes Ye Yes Yes Yes Yes Yes
Tagalog Yes Yes EN No Yes Yes Yes Yes
Tahitian Yes No Yes Yes Yes Yes C Yes
Tinpo Yes Yes EN No Yes Yes Yes Yes
Tongan Yes Yes EN No Yes Yes Yes Yes
Tswana (Chuana) Yes No No Yes Yes Yes C Yes
Tun * Yes Yes EN No Yes Yes Yes Yes
Turkish Yes No Yes Yes Yes No Yes T
Ukrainian Yes No Yes Yes Yes No No
Visayan Yes Yes EN No Yes Yes Yes Yes
Welsh Yes No Yes Yes Yes Yes W Yes W
Wolof Yes No No Yes Yes Yes C Yes
Xhosa Yes Yes EN No Yes Yes Yes Yes
Zapotec Yes Yes EN No Yes Yes Yes Yes
Zulu Yes No Yes Yes Yes No Yes

* = 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.

See Also

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