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OcrException Class

Summary

Represents the exception that is thrown when a runtime error occurs inside the IOcrEngine

Syntax

C#
VB
Java
C++
[SerializableAttribute()] 
public class OcrException : Exception 

<SerializableAttribute()> 
Public Class OcrException  
   Inherits System.Exception 
   Implements System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable  

public class OcrException extends RuntimeException 

[SerializableAttribute()] 
public ref class OcrException : public System.Exception, System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable   

Remarks

When a runtime error occurs in the IOcrEngine, an exception of type OcrException is thrown with the engine-specific error code set in the Code member. This error code is engine-specific but a short description can be obtained using the Message property of this class or by using the IOcrEngine.GetErrorCodeString method.

Logic errors such as invalid parameters to methods or invalid operations throw standard .NET exceptions (in this case, ArgumentException and InvalidOperationException respectively Errors caused by loading invalid image files using IOcrEngine.RasterCodecsInstance will throw exceptions of type RasterException. Errors for missing features (support locked) will throw OcrSupportLockedException exceptions. Any other runtime error in the engine will throw an OcrException.

Example

This example shows how to trap various types of exceptions during OCR operations.

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Document.Writer; 
 
public void OcrExceptionExample() 
{ 
   try 
   { 
      // Create an instance of the engine 
      using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD, false)) 
      { 
         // Start the engine using default parameters 
         ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
 
         string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); 
         string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf"); 
 
         // Create a page 
         // Create an OCR document 
         using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) 
         { 
            // Add a page to the document 
            IOcrPage ocrPage = ocrDocument.Pages.AddPage(tifFileName, null); 
 
            // Recognize the page 
            // Note, Recognize can be called without calling AutoZone or manually adding zones. The engine will 
            // check and automatically auto-zones the page 
            ocrPage.Recognize(null); 
 
            // Save the document we have as PDF 
            ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, null); 
         } 
 
         // Shutdown the engine 
         // Note: calling Dispose will also automatically shutdown the engine if it has been started 
         ocrEngine.Shutdown(); 
      } 
   } 
   catch (OcrSupportLockedException ex) 
   { 
      Console.WriteLine("Support is locked. You need to unlock '{0}' in this engine to use this feature", ex.SupportType); 
   } 
   catch (OcrException ex) 
   { 
      Console.WriteLine("OCR Error\nCode: {0}\nMessage:{1}", ex.Code, ex.Message); 
   } 
   catch (RasterException ex) 
   { 
      Console.WriteLine("LEADTOOLS Error\nCode: {0}\nMessage:{1}", ex.Code, ex.Message); 
   } 
   catch (Exception ex) 
   { 
      Console.WriteLine("System Error\nMessage:{0}", ex.Message); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime"; 
} 

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Ocr 
Imports Leadtools.Document.Writer 
 
Public Sub OcrExceptionExample() 
   Try 
      ' Create an instance of the engine 
      Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD, False) 
         ' Start the engine using default parameters 
         ocrEngine.Startup(Nothing, Nothing, Nothing, LEAD_VARS.OcrLEADRuntimeDir) 
 
         Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif") 
         Dim pdfFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf") 
 
         ' Create a page 
         ' Create an OCR document 
         Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument() 
            ' Add a page to the document 
            Dim ocrPage As IOcrPage = ocrDocument.Pages.AddPage(tifFileName, Nothing) 
 
            ' Recognize the page 
            ' Note, Recognize can be called without calling AutoZone or manually adding zones. The engine will 
            ' check and automatically auto-zones the page 
            ocrPage.Recognize(Nothing) 
 
            ' Save the document we have as PDF 
            ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, Nothing) 
         End Using 
 
         ' Shutdown the engine 
         ' Note: calling Dispose will also automatically shutdown the engine if it has been started 
         ocrEngine.Shutdown() 
      End Using 
   Catch ex As OcrSupportLockedException 
      Console.WriteLine("Support is locked. You need to unlock '{0}' in this engine to use this feature", ex.SupportType) 
   Catch ex As OcrException 
      Console.WriteLine("OCR Error" & vbLf & "Code: {0}" & vbLf & "Message:{1}", ex.Code, ex.Message) 
   Catch ex As RasterException 
      Console.WriteLine("LEADTOOLS Error" & vbLf & "Code: {0}" & vbLf & "Message:{1}", ex.Code, ex.Message) 
   Catch ex As Exception 
      Console.WriteLine("System Error" & vbLf & "Message:{0}", ex.Message) 
   End Try 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
   Public Const OcrLEADRuntimeDir As String = "C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime" 
End Class 

Requirements

Target Platforms

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Leadtools.Ocr Assembly