Rectangular area on a page containing a feature of interest to the user.
The OcrZone class contains all the necessary information for describing a zone. A zone is a rectangular area on an image containing a feature of interest to the user. The image data covered by each zone is handled and processed (typically recognized) separately.
Access the zones of a page with the OcrPageZones.Zones property. This is a collection allowing the user to examine and modify the various zones on the page.
Zones can be divided into two basic categories: whether a zone is to be recognized or whether it should be treated as graphic. Zones containing text information can be considered to be either of the flowing type or of a table type. This basic classification of zones helps the OCR engine handle text information correctly.
Zones are always associated with a filling method (OcrZoneFillMethod) and one of the available recognition modules (OcrZoneRecognitionModule). These determine which recognition algorithm will be applied to the zone during its processing.
Use the CharacterFilters property to modify the set of valid characters for recognition of the zone. Specifying the character set correctly is a recognition accuracy issue.
Other members of the zone class specify how the checking subsystem will function for the particular zone.
When adding or updating a zone directly initialize the OcrZone.Bounds, OcrZone.FillMethod, OcrZone.RecognitionModule, OcrZone.CharacterFilters and the OcrZone.ZoneType properties of the zone, since they will not take on their default values.
The OcrZone.ZoneType property of the updating zone should be one of the following: OcrZoneType.Text, OcrZoneType.Table or OcrZoneType.Graphics.
It is the developers responsibility to specify a valid recognition module-filling method pair. Otherwise any incorrectly set zone will have no recognition result. For more information, refer to An Overview of OCR Recognition Modules.
LEADTOOLS OCR .NET also supports OMR (Optical Mark Recognition) in all the engines. For more information, refer to Using OMR in LEADTOOLS .NET OCR.
For an example, refer to DocumentConvertOptions.PagesZones
