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EnhanceLocalContrast Method of the ImageDocument Object

This method increases the local contrast of the image. Such preprocessing may increase recognition quality of low contrast images. The images for which this preprocessing method is effective include:

  • photos or scans of documents with texture or pictures in the background. With the normal binarization procedure, the characters that coincide with darker areas of background may be lost or recognized unreliably. If you apply this method before recognition, such areas are detected, and contrast is increased, with the result that after binarization the characters stand out more distinctly.

See the illustration

  • photos or scans of documents with highly colorful background or text highlighting.

See the illustration

We recommend that you call this method at the beginning of a preprocessing procedure (before orientation and resolution detection, but after the image cropping).

Important! This method can be used for color and gray images only.



HRESULT EnhanceLocalContrast();


void EnhanceLocalContrast();

Visual Basic .NET

Sub EnhanceLocalContrast()

Return values

This method has no specific return values. It returns the standard return values of ABBYY FineReader Engine functions.

See also



03.07.2024 8:50:44

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