AddPages(RasterImage,Int32,Int32,OcrProgressCallback) Method

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Visual Basic
WinRT C#
Java
Objective-C
WinRT JavaScript
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void AddPages( 
   RasterImage image,
   int imageFirstPageNumber,
   int imageLastPageNumber,
   OcrProgressCallback callback
)

'Declaration

Overloads Sub AddPages( _
   ByVal image As RasterImage, _
   ByVal imageFirstPageNumber As Integer, _
   ByVal imageLastPageNumber As Integer, _
   ByVal callback As OcrProgressCallback _
)

'Usage

Dim instance As IOcrPageCollection
Dim image As RasterImage
Dim imageFirstPageNumber As Integer
Dim imageLastPageNumber As Integer
Dim callback As OcrProgressCallback
 
instance.AddPages(image, imageFirstPageNumber, imageLastPageNumber, callback)

void AddPages( 
   RasterImage image,
   int imageFirstPageNumber,
   int imageLastPageNumber,
   OcrProgressCallback callback
)

- (BOOL)addPagesWithImage:(LTRasterImage *)image 
                  inRange:(NSRange)range 
                    error:(NSError **)error

public void addPages(RasterImage image,
                     int imageFirstPageNumber,
                     int imageLastPageNumber,
                     OcrProgressListener callback)

function Leadtools.Forms.Ocr.IOcrPageCollection.AddPages(RasterImage,Int32,Int32,OcrProgressCallback)( 
   image ,
   imageFirstPageNumber ,
   imageLastPageNumber ,
   callback 
)

void AddPages( 
   RasterImage^ image,
   int imageFirstPageNumber,
   int imageLastPageNumber,
   OcrProgressCallback^ callback
)

Parameters

image: The RasterImage object containing the pages to add.
imageFirstPageNumber: 1-based index of the first page in image to add.
imageLastPageNumber: 1-based index of the last page in image to add. A value of -1 means add up to and including the last page in image.
callback: Optional callback to show operation progress.

This method copies the RasterImage object image data into the newly created IOcrPage. Therefore, after this method returns, there is no relationship between image and the IOcrPage inside the OCR document. For example, if you do not need the image object after calling this method, you should dispose it after this method returns.

This method guarantees that no changes will be made to image.

A short-cut to add all the pages of a RasterImage object to the OCR document is AddPages(image, 1, -1, callback).

To add a single page from a RasterImage object, you can use AddPage(RasterImage image, OcrProgressCallback callback).

This method will add the page(s) to the end of the collection if you already have pages in this IOcrPageCollection.

You can use the OcrProgressCallback to show the operation progress or to abort it. For more information and an example, refer to OcrProgressCallback.

The LEADTOOLS OCR engine supports pages of dots per inch (DPI) values of 150 and greater. If you try to add a page with a DPI of less than 150 then the engine might be able to recognize any data from this page.

Note: The value of the "Recognition.ShareOriginalImage" (only supported by the Advantage OCR engine) setting is not used when calling this method. The engine will make a copy of image and store it in the page. Calling IOcrPage.GetRasterImage(OcrPageType.Original) on the page will return a null reference.

This member only works with memory-based documents and will throw an exception otherwise. For more information, refer to IOcrDocumentManager.CreateDocument and Programming with the LEADTOOLS .NET OCR.

This example will load multiple pages into a RasterImage object then add them to the OCR engine.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Forms.Ocr
Imports Leadtools.Forms.DocumentWriters
Imports Leadtools.Forms
Imports Leadtools.ImageProcessing.Core

<TestMethod>
Public Sub AddMultiPageRasterImageExample()
   Dim pdfFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf")
   ' Load the Ocr1.tif, Ocr2.tif, Ocr3.tif and Ocr4.tif to a single RasterImage object
   Dim codecs As New RasterCodecs()

   Dim image As RasterImage = Nothing
   For i As Integer = 0 To 3
      Dim pageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, String.Format("Ocr{0}.tif", i + 1))
      Dim tempImage As RasterImage = codecs.Load(pageFileName)
      If image Is Nothing Then
         image = tempImage
      Else
         image.AddPage(tempImage)
      End If
   Next

   Console.WriteLine("RasterImage has {0} pages", image.PageCount)

   ' Create an instance of the engine
   Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, False)
      ' Since we have a RasterCodecs object, re-use it in the OCR engine. Although
      ' this demo will not use it, it is always a good practice
      ocrEngine.Startup(codecs, Nothing, Nothing, LEAD_VARS.OcrAdvantageRuntimeDir)

      ' Create an OCR document
      Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument()
         ' Add the 2nd and 3rd pages to the document
         Console.WriteLine("Adding the pages from 2 to 3 to the document")
         ocrDocument.Pages.AddPages(image, 2, 3, Nothing)
         Console.WriteLine("Document has {0} pages", ocrDocument.Pages.Count)

         ' We do not need the image anymore
         image.Dispose()

         ' Recognize
         ocrDocument.Pages.Recognize(Nothing)

         ' Save
         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

   codecs.Dispose()
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
Public Const OcrAdvantageRuntimeDir As String = "C:\LEADTOOLS 19\Bin\Common\OcrAdvantageRuntime"
End Class

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Forms.Ocr;
using Leadtools.Forms.DocumentWriters;
using Leadtools.Forms;
using Leadtools.ImageProcessing.Core;

public void AddMultiPageRasterImageExample()
{
   string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf");
   // Load the Ocr1.tif, Ocr2.tif, Ocr3.tif and Ocr4.tif to a single RasterImage object
   RasterCodecs codecs = new RasterCodecs();

   RasterImage image = null;
   for (int i = 0; i < 4; i++)
   {
      string pageFileName = Path.Combine(LEAD_VARS.ImagesDir, string.Format("Ocr{0}.tif", i + 1));
      RasterImage tempImage = codecs.Load(pageFileName);
      if (image == null)
         image = tempImage;
      else
         image.AddPage(tempImage);
   }

   Console.WriteLine("RasterImage has {0} pages", image.PageCount);

   // Create an instance of the engine
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, false))
   {
      // Since we have a RasterCodecs object, re-use it in the OCR engine. Although
      // this demo will not use it, it is always a good practice
      ocrEngine.Startup(codecs, null, null, LEAD_VARS.OcrAdvantageRuntimeDir);

      // Create an OCR document
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument())
      {
         // Add the 2nd and 3rd pages to the document
         Console.WriteLine("Adding the pages from 2 to 3 to the document");
         ocrDocument.Pages.AddPages(image, 2, 3, null);
         Console.WriteLine("Document has {0} pages", ocrDocument.Pages.Count);

         // We do not need the image anymore
         image.Dispose();

         // Recognize
         ocrDocument.Pages.Recognize(null);

         // Save
         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();
   }

   codecs.Dispose();
}

static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
public const string OcrAdvantageRuntimeDir = @"C:\LEADTOOLS 19\Bin\Common\OcrAdvantageRuntime";
}

Target Platforms

Reference

IOcrPageCollection Interface
IOcrPageCollection Members
Overload List
OcrEngineManager Class
OcrEngineType Enumeration
IOcrPage Interface
Programming with the LEADTOOLS .NET OCR