TIEVisionOCR.recognize

Declaration

function recognize(image: TIEVisionImage; const rect: TIEVisionRect): TIEVisionWString; safecall;

Description

Perform OCR on the specified area of the image returning an ANSI string.


Note: A shortcut method for this is available: OCR

Recommendations for Best Results

To improve the your OCR result ensure your input images are of good quality, and you may need to pre-process the image for optimal results. Ideally the text height should be at least 20 pixels, any rotation or skew should be corrected, low-frequency changes in brightness should be high-pass filtered and dark borders manually removed so they are not misinterpreted as characters.

For more information, see: tesseract-ocr.github.io/tessdoc/ImproveQuality

Demos

Example 1

Perform OCR:

OCR := IEVisionLib.createOCR(IEOCRLanguageList[OCR_English_language].Code);
str := OCR.recognize(ImageEnView1.IEBitmap.GetIEVisionImage(), IEVisionRect(0, 0, 0, 0)).c_str();

Example 2

Allow switching of language:

// Set language based on selection
Case LanguageRadioGroup.ItemIndex of
  0 : OCR := IEVisionLib.createOCR(IEOCRLanguageList[OCR_English_language].Code);
  1 : OCR := IEVisionLib.createOCR(IEOCRLanguageList[OCR_French_language].Code);
  2 : OCR := IEVisionLib.createOCR(IEOCRLanguageList[OCR_German_language].Code);
End;

// Perform OCR
str := OCR.recognize(ImageEnView1.IEBitmap.GetIEVisionImage(), IEVisionRect(0, 0, 0, 0)).c_str();

// Reset OCR object
OCR := nil;

Example 3

Multiple languages:

var
  langs: TIEVisionVectorString;
langs := IEVisionLib.createVectorString();
langs.push_back( IEOCRLanguageList[ OCR_English_language ].Code );  // load English
langs.push_back( IEOCRLanguageList[ OCR_Italian_language ].Code );  // load Italian
m_OCR := IEVisionLib.createOCR( '', langs );
str := m_OCR.recognize(ImageEnView1.IEBitmap.GetIEVisionImage(), IEVisionRect(0, 0, 0, 0)).c_str();

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