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OcrZoneCharacterFilters Enumeration


Character set filter.

public enum OcrZoneCharacterFilters 
Public Enum OcrZoneCharacterFilters  
typedef NS_OPTIONS(NSUInteger, LTOcrZoneCharacterFilters) 
public enum OcrZoneCharacterFilters 
public enum class OcrZoneCharacterFilters   

0x00000000None No character filters.
0x00000001Digit Recognition of numerals only. For example: "3" (Digit Three).
0x00000002Uppercase Recognition of uppercase letters only, including accented ones. For example: "A" (Capital A).
0x00000004Lowercase Recognition of lowercase letters only including accented ones. For example: "a" (Lowercase a).
0x00000006Alpha Upper and lowercase letters only. This is a combination of (Uppercase | Lowercase).
0x00000008Punctuation Recognition of punctuation signs only. For example: "!" (Exclamation Mark).
0x00000010Miscellaneous Recognition of other miscellaneous characters only. For example: "+" (Plus sign).
0x0000001FAll All characters. Since all elements are enabled, there is no filtering. This a combination of Digit (| Uppercase | Lowercase | Punctuation | Miscellaneous).
0x00000020Plus Enables the use of the "FilterPlus" characters. The FilterPlus characters are added after any filtering. For more information, refer to LEADTOOLS OCR Module - OmniPage Engine Settings.
0x00000021Numbers Digits plus the "FilterPlus" characters This is a combination of (Digit | Plus).


This enumeration lists the available character set filter elements. The Language environment can be narrowed by specifying Character Set filters. The name of each filter element indicates which category of characters it validates. This enumeration is attributes with the FlagsAttribute and its members can be combined (OR-ed) together.

The filters can have an effect either at zone level (by specifying the zone's OcrZone.CharacterFilters property), or globally, at image level (defined by the "Recognition.DefaultCharacterFilter" setting).

The way to set no filtering is to give the value OcrZoneCharacterFilters.All.

Characters of the document that are not part of the specified character set will either be rejected or will be recognized as a validated character with a similar shape. For instance, if only the English language has been selected and the document contains a letter "Capital A with acute", then the recognized output will be a letter "Capital A"


For an example, refer to IOcrPage.AutoZone.


Target Platforms

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