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MissingSymbol Property

Gets or sets the character used as a symbol for the missing characters in the final output document.
public char MissingSymbol { get; set; } 
public char getMissingSymbol() 
public void setMissingSymbol(char value) 
property char MissingSymbol { 
   char get(); 
   void set (    char ); 
MissingSymbol # get and set (IOcrDocumentManager) 

Property Value

The character used as a symbol for the missing characters in the final output document.


The missing symbol is a special character that replaces another character that was recognized by the engine but could not be represented in the final output document, since the character does not exist in the current code page.

During the conversion to the final output document the IOcrDocument.Save or IOcrDocument.SaveXml methods will try to find a replacement character with a similar shape for one not supported by the current code page. Only if this attempt was not successful the missing symbol will be sent into the final output document.

The default missing symbol is "^" (the circumflex character)

For more information on recognition and rejected and missing symbols, refer to IOcrPage.Recognize.

Note: This property is not supported in the LEADTOOLS OCR Module - LEAD Engine

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Forms.Common; 
using Leadtools.Document.Writer; 
using Leadtools.WinForms; 
public void OcrDocumentManagerExample() 
   string tifFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); 
   string tifFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Ocr2.tif"); 
   string outputDirectory = Path.Combine(LEAD_VARS.ImagesDir, "OutputDirectory"); 
   // Create the output directory 
   if (Directory.Exists(outputDirectory)) 
      Directory.Delete(outputDirectory, true); 
   // Create an instance of the engine 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
      // Start the engine using default parameters 
      Console.WriteLine("Starting up the engine..."); 
      ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
      // Create the OCR document 
      Console.WriteLine("Creating the OCR document..."); 
      IOcrDocumentManager ocrDocumentManager = ocrEngine.DocumentManager; 
      using (IOcrDocument ocrDocument = ocrDocumentManager.CreateDocument()) 
         // Add the pages to the document 
         Console.WriteLine("Adding the pages..."); 
         ocrDocument.Pages.AddPage(tifFileName1, null); 
         ocrDocument.Pages.AddPage(tifFileName2, null); 
         // Recognize the pages to this document. Note, we did not call AutoZone, it will explicitly be called by Recognize 
         Console.WriteLine("Recognizing all the pages..."); 
         // Save to all the formats supported by this OCR engine 
         Array formats = Enum.GetValues(typeof(DocumentFormat)); 
         foreach (DocumentFormat format in formats) 
            string friendlyName = DocumentWriter.GetFormatFriendlyName(format); 
            Console.WriteLine("Saving (using default options) to {0}...", friendlyName); 
            // Construct the output file name (output_directory + document_format_name + . + extension) 
            string extension = DocumentWriter.GetFormatFileExtension(format); 
            string outputFileName = Path.Combine(outputDirectory, format.ToString() + "." + extension); 
            // Save the document 
            ocrDocument.Save(outputFileName, format, null); 
            // If this is the LTD format, convert it to PDF 
            if (format == DocumentFormat.Ltd) 
               Console.WriteLine("Converting the LTD file to PDF..."); 
               string pdfFileName = Path.Combine(outputDirectory, format.ToString() + "_pdf.pdf"); 
               DocumentWriter docWriter = ocrEngine.DocumentWriterInstance; 
               docWriter.Convert(outputFileName, pdfFileName, DocumentFormat.Pdf); 
         // Now save to all the engine native formats (if any) supported by the engine 
         string[] engineFormats = ocrDocumentManager.GetSupportedEngineFormats(); 
         foreach (string engineFormat in engineFormats) 
            string friendlyName = ocrDocumentManager.GetEngineFormatFriendlyName(engineFormat); 
            Console.WriteLine("Saving to engine native format {0}...", friendlyName); 
            // Construct the output file name (output_directory + "engine" + engine_format_name + . + extension) 
            string extension = ocrDocumentManager.GetEngineFormatFileExtension(engineFormat); 
            string outputFileName = Path.Combine(outputDirectory, "engine_" + engineFormat + "." + extension); 
            // To use this format, set it in the IOcrDocumentManager.EngineFormat and do a normal save using DocumentFormat.User 
            // Save the document 
            ocrDocumentManager.EngineFormat = engineFormat; 
            ocrDocument.Save(outputFileName, DocumentFormat.User, null); 
      // Shutdown the engine 
      // Note: calling Dispose will also automatically shutdown the engine if it has been started 
      Console.WriteLine("Shutting down..."); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS22\Bin\Common\OcrLEADRuntime"; 

Target Platforms

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Leadtools.Ocr Assembly

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.