NativeOcrZoneRecognitionModule Enumeration

Used with engine-specific zones. For more information, refer to IOcrZoneManager.GetNativeZone and IOcrZoneManager.SetNativeZone.

The NativeOcrZoneRecognitionModule contains the different recognition modules of the engine available to you. A recognition module must have been assigned to all zones in their NativeOcrZone.RecognitionModule properties before processing.

Not all recognition modules are available to all engines. To determine which recognition modules are available use IOcrZoneManager.GetSupportedNativeRecognitionModules. Trying to set a recognition module that is not available to the engine will cause an error.

Each zone needs to be associated with a NativeOcrZoneRecognitionModule and a NativeOcrZoneFillMethod. This is needed because some recognition modules support more than one fill method, and some fill methods are accepted by more than one recognition module. It is important to ensure that the recognition module/fill method pair is suitable. For example, the multi-lingual MOR omnifont recognition module NativeOcrZoneRecognitionModule.OmniFontMor is capable of recognizing omnifont machine print (NativeOcrZoneFillMethod.OmniFont), 24-pin draft dot-matrix print (NativeOcrZoneFillMethod.DraftDot24), OCR-A (NativeOcrZoneFillMethod.OcrA) and OCR-B (NativeOcrZoneFillMethod.OcrB) texts.

For precise information on permitted recognition module/fill method pairs refer to An Overview of OCR Recognition Modules.

NativeOcrZoneRecognitionModule.Auto can be set in the NativeOcrZone.RecognitionModule property by the user. It will also be generated by IOcrPage.AutoZone (auto-zoning) and will, under certain circumstances, be generated by the IOcrPage.UpdateNativeFillMethod method.

Force the use of a particular recognition module by specifying it directly in the zone's NativeOcrZone.RecognitionModule property after calling IOcrPage.AutoZone or IOcrPage.UpdateNativeFillMethod.

When NativeOcrZoneRecognitionModule.Auto is set, the recognition module is chosen primarily by the fill method (either directly specified, taken as default or auto-detected). The choices will be as follows:

In the first nine cases, only the fill method will be used to determine the recognition module: there will be no checking whether other settings are suitable. The last three will be directed to NativeOcrZoneRecognitionModule.OmniFontMText, unless the engine finds a language, filter or other setting which is not supported by this module.

With the NativeOcrZoneFillMethod.Icr and NativeOcrZoneRecognitionModule.IcrCharacter will be chosen if letters or other characters unsupported by NativeOcrZoneRecognitionModule.IcrNumeral are validated for recognition.

Note: The NativeOcrZoneFillMethod.Icr or NativeOcrZoneRecognitionModule.IcrCharacter values are no longer recommended when the LEADTOOLS OCR Module - OmniPage Engine is being used to recognize ICR numeric characters. Use the Digit member of the OcrZoneCharacterFilters enumeration instead.

For more information, see the An Overview of OCR Recognition Modules.

As an example, suppose the zone's fill method is NativeOcrZoneFillMethod.OmniFont and NativeOcrZoneRecognitionModule.Auto has been specified.

• If only English and/or the main West European language characters are to be validated for recognition, then the M/TEXT omnifont recognition module (NativeOcrZoneRecognitionModule.OmniFontMText) will be automatically selected.

• However, if e.g. Polish characters are also to be recognized, the engine will select the multi-lingual MOR omnifont recognition module NativeOcrZoneRecognitionModule.OmniFontMor, since the M/TEXT recognition module does not support Polish characters, but the MOR recognition module does.

Target Platforms

Reference

Leadtools.Ocr Namespace

AutoZone Method

NativeOcrZoneFillMethod Enumeration

OcrEngineManager Class

OcrEngineType Enumeration

IOcrPageCollection Interface

IOcrZoneCollection Interface

NativeOcrZone Structure

Programming with the LEADTOOLS .NET OCR

An Overview of OCR Recognition Modules