StoreOcrPageCharacters Property

Summary

Indicates whether to store the recognized OCR object used to obtain the text in this DocumentPageText.

Syntax

C++

public bool StoreOcrPageCharacters {get; set;}

Public Property StoreOcrPageCharacters() As Boolean 
   Get 
   Set

public:  
   property bool StoreOcrPageCharacters 
   { 
      bool get() 
      void set(bool value) 
   }

Property Value

true to store the recognized OCR object used to obtain the text in this DocumentPageText; otherwise, false. The default value is false.

Remarks

When DocumentPage.GetText is called, the engine tries to parse the text of the page using either the SVG or OCR engines.

When the OCR engine is used, the engine creates a valid IOcrPage object and calls Recognize. It then parses the resulting OCR characters(stored in an IOcrPageCharacters object), and converts them to DocumentCharacters and adds them to the page DocumentPageText.Characters collection. Each resulting DocumentCharacter object will contain DocumentCharacter.IsFromOcr set to true (since it was obtained through OCR), and the values of DocumentCharacter.OcrZoneIndex and DocumentCharacter.OcrCharacterIndex set the zone and character index into the IOcrPageCharacters object used to obtain it.

This conversion will obtain some of the values stored in an OcrCharacter object such as the character code and location. Other information obtained by the OCR engine such as the color, confidence, and baseline are not converted and will be lost.

When the value of StoreOcrPageCharacters is set to false (the default value), then the IOcrPageCharacters object used to create these document characters is created internally and not saved and the information is lost.

When the value of StoreOcrPageCharacters is set to true, then the IOcrPageCharacters object used to create these document characters will be stored in the DocumentPageText.OcrPageCharacters property and can be used to obtain all the other OCR information of the character.

The example below shows how to use StoreOcrPageCharacters to obtain the OCR confidence value for each document character.

For more information on text parsing refer Parsing Text with the Document Library.

Example

This example will get the text from a document page using OCR and then use StoreOcrPageCharacters and DocumentPageText.OcrPageCharacters to find the OCR character confidences.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Document.Writer; 
 
using Leadtools.Document; 
using Leadtools.Caching; 
using Leadtools.Annotations.Engine; 
using Leadtools.Ocr; 
using Leadtools.Barcode; 
using Leadtools.Document.Converter; 
 
public void StoreOcrPageCharactersExample() 
{ 
	// Initialize an OCR engine 
	IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD); 
	// Start the engine using default parameters 
	ocrEngine.Startup(null, null, null, @"C:\LEADTOOLS21\Bin\Common\OcrLEADRuntime"); 
 
	// Load a document that we know will be OCRed 
	string documentFile = @"C:\LEADTOOLS21\Resources\Images\ocr1.tif"; 
	using (LEADDocument document = DocumentFactory.LoadFromFile(documentFile, new LoadDocumentOptions())) 
	{ 
		// Set the OCR engine 
		document.Text.OcrEngine = ocrEngine; 
		// First, do not store IOcrPageCharacters in DocumentPageText, this will 
		// cause our code to extract the character OCR confidences value to not work 
		document.Text.StoreOcrPageCharacters = false; 
		Console.WriteLine("Obtaining OCR characters confidence with StoreOcrPageCharacters equals to false. Should fail"); 
 
		// Now get the text 
		DocumentPage documentPage = document.Pages[0]; 
		DocumentPageText documentPageText = documentPage.GetText(); 
		// Build the words 
		documentPageText.BuildWords(); 
		ShowOcrConfidence(documentPageText); 
 
		Console.WriteLine("Obtaining OCR characters confidence with StoreOcrPageCharacters equals to true. Should work"); 
		document.Text.StoreOcrPageCharacters = true; 
		documentPageText = documentPage.GetText(); 
		// Build the words 
		documentPageText.BuildWords(); 
		ShowOcrConfidence(documentPageText); 
	} 
	ocrEngine.Dispose(); 
} 
 
private static void ShowOcrConfidence(DocumentPageText documentPageText) 
{ 
	Console.WriteLine("Showing OCR confidence value of the characters of the first word"); 
	if (documentPageText.Words == null) 
	{ 
		Console.WriteLine("Nothing to show"); 
		return; 
	} 
 
	// Show the OCR character confidence for the first word 
	// Get the first word 
	DocumentWord word = documentPageText.Words[0]; 
	Console.WriteLine($"first word value:{word.Value}"); 
	// Get its characters 
	for (int characterIndex = word.FirstCharacterIndex; characterIndex <= word.LastCharacterIndex; characterIndex++) 
	{ 
		DocumentCharacter documentCharacter = documentPageText.Characters[characterIndex]; 
		Console.WriteLine($" character at index {characterIndex} is {documentCharacter.Code} and its isFromOcr value is {documentCharacter.IsFromOcr}"); 
		// Ensure this is a character obtained from OCR 
		if (documentCharacter.IsFromOcr) 
		{ 
			// See if we stored the IOcrPageCharacters in  
			if (documentPageText.OcrPageCharacters != null) 
			{ 
				// We have it, get the corresponding OcrCharcater 
				// Get the zone characters 
				IOcrZoneCharacters ocrZoneCharacters = documentPageText.OcrPageCharacters[documentCharacter.OcrZoneIndex]; 
				// And the character in this zone 
				OcrCharacter ocrCharacter = ocrZoneCharacters[documentCharacter.OcrCharacterIndex]; 
				int confidence = ocrCharacter.Confidence; 
				Console.WriteLine($"   OCR character code is {ocrCharacter.Code} and confidence is {confidence}"); 
				// Sanity check 
				Debug.Assert(ocrCharacter.Code == documentCharacter.Code); 
			} 
			else 
			{ 
				Console.WriteLine("   Failed to get OCR confidence"); 
			} 
		} 
	} 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Document.Writer 
Imports Leadtools.Svg 
Imports Leadtools.Document 
Imports Leadtools.Caching 
Imports Leadtools.Annotations.Engine 
Imports Leadtools.Barcode 
Imports Leadtools.Ocr 
Imports LeadtoolsDocumentExamples.LeadtoolsExamples.Common 
Imports Leadtools.Document.Converter 
 
Public Shared Sub StoreOcrPageCharactersExample() 
   ' Initialize an OCR engine 
   Dim ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD) 
   ' Start the engine using default parameters 
   ocrEngine.Startup(Nothing, Nothing, Nothing, "C:\LEADTOOLS21\Bin\Common\OcrLEADRuntime") 
 
   ' Load a document that we know will be OCRed 
   Dim documentFile As String = "C:\LEADTOOLS21\Resources\Images\ocr1.tif" 
   Using document As LEADDocument = DocumentFactory.LoadFromFile(documentFile, New LoadDocumentOptions()) 
      ' Set the OCR engine 
      document.Text.OcrEngine = ocrEngine 
      ' First, do not store IOcrPageCharacters in DocumentPageText, this will 
      ' cause our code to extract the character OCR confidences value to not work 
      document.Text.StoreOcrPageCharacters = False 
      Console.WriteLine("Obtaining OCR characters confidence with StoreOcrPageCharacters equals to false. Should fail") 
 
      ' Now get the text 
      Dim documentPage As DocumentPage = document.Pages(0) 
      Dim documentPageText As DocumentPageText = documentPage.GetText() 
      ' Build the words 
      documentPageText.BuildWords() 
      ShowOcrConfidence(documentPageText) 
 
      Console.WriteLine("Obtaining OCR characters confidence with StoreOcrPageCharacters equals to true. Should work") 
      document.Text.StoreOcrPageCharacters = True 
      documentPageText = documentPage.GetText() 
      ' Build the words 
      documentPageText.BuildWords() 
      ShowOcrConfidence(documentPageText) 
   End Using 
   ocrEngine.Dispose() 
End Sub 
 
Private Shared Sub ShowOcrConfidence(documentPageText As DocumentPageText) 
   Console.WriteLine("Showing OCR confidence value of the characters of the first word") 
   If IsNothing(documentPageText.Words) Then 
      Console.WriteLine("Nothing to show") 
      Return 
   End If 
 
   ' Show the OCR character confidence for the first word 
   ' Get the first word 
   Dim word As DocumentWord = documentPageText.Words(0) 
   Console.WriteLine($"first word value:{word.Value}") 
   ' Get its characters 
   For characterIndex As Integer = word.FirstCharacterIndex To word.LastCharacterIndex 
      Dim DocumentCharacter As DocumentCharacter = documentPageText.Characters(characterIndex) 
      Console.WriteLine($" character at index {characterIndex} is {DocumentCharacter.Code} and its isFromOcr value is {DocumentCharacter.IsFromOcr}") 
      ' Ensure this is a character obtained from OCR 
      If DocumentCharacter.IsFromOcr Then 
         ' See if we stored the IOcrPageCharacters in  
         If Not IsNothing(documentPageText.OcrPageCharacters) Then 
            ' We have it, get the corresponding OcrCharcater 
            ' Get the zone characters 
            Dim ocrZoneCharacters As IOcrZoneCharacters = documentPageText.OcrPageCharacters(DocumentCharacter.OcrZoneIndex) 
            ' And the character in this zone 
            Dim OcrCharacter As OcrCharacter = ocrZoneCharacters(DocumentCharacter.OcrCharacterIndex) 
            Dim confidence As Integer = OcrCharacter.Confidence 
            Console.WriteLine($"   OCR character code is {OcrCharacter.Code} and confidence is {confidence}") 
            ' Sanity check 
            Debug.Assert(OcrCharacter.Code = DocumentCharacter.Code) 
         Else 
            Console.WriteLine("   Failed to get OCR confidence") 
         End If 
      End If 
   Next 
End Sub

Requirements

Target Platforms

Reference

DocumentText Class

DocumentText Members

Leadtools.Document Namespace

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