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TesseractOcrJobRequestImagePreProcessing Class
Specifies the image pre-processing filters or operations to be executed on the specified image before sending it to the ocr engine.
Inheritance Hierarchy
SystemObject
  DevScope.Ocr.Tesseract.WindowsTesseractOcrJobRequestImagePreProcessing

Namespace: DevScope.Ocr.Tesseract.Windows
Assembly: DevScope.Ocr.Tesseract.Windows.x86 (in DevScope.Ocr.Tesseract.Windows.x86.dll) Version: 2.0.0.0 (2.0.0.0)
Syntax
public class TesseractOcrJobRequestImagePreProcessing

The TesseractOcrJobRequestImagePreProcessing type exposes the following members.

Constructors
  NameDescription
Public methodTesseractOcrJobRequestImagePreProcessing
Initializes a new instance of the TesseractOcrJobRequestImagePreProcessing class
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Methods
  NameDescription
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as a hash function for a particular type.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Properties
  NameDescription
Public propertyAutoCleanBlackBorders
Automatically eliminates black borders from page images and helps to reduce image complexity.
Public propertyAutoDeskew
Deskew filter, also called auto straighten, is the automatic rotation of an image such that the text is vertically aligned. This is great for straighten up scanned documents.
Public propertyAutoDespeckle

This filter is used to automatically remove small defects due to dust, or scratches, on a scanned image, and also moiré effects on image scanned from a magazine.

Please note that this filter assumes that the text characters height is greater than 20 pixels by assuming the page image was scanned at least at 250 dpi. If there are character height lower than the previous mentioned height then this filter should not be used because it will probably remove good text parts.

Public propertyAutoInvert
Negative documents are documents that have a reverse color photometry: text is white, and the background is black. Since the OCR document recognition assumes the opposite, this filter automatically detects and inverts color photometry in a image.
Public propertyImageResize
Resizes a page image according to the TesseractOcrImageResizeSettings
Public propertyLocalAdaptiveThresholding
Thresholding is the simplest way to segment objects from a background. If that background is relatively uniform, then you should leave this setting to null or set its Enabled property to false (which is the default behaviour) and a global threshold value will be used to binarize the image by pixel-intensity. If there’s large variation in the background intensity (like a camera image), however, adaptive thresholding (a.k.a. local or dynamic thresholding) may produce better results.
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See Also