AddPages(RasterImage,Int32,Int32,OcrProgressCallback) Method

Adds one or more pages from a multi-page Leadtools.RasterImage object.

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

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
)

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 Leadtools.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.

Remarks

This method copies the Leadtools.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 Leadtools.RasterImage object to the OCR document is AddPages(image, 1, -1, callback).

To add a single page from a Leadtools.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 LEADTOOLS Plus OCR engine does not support image size greater than A3 paper size (11.7 by 16.5 inches at 300 dpi). Attempting to add an image that has a size greater than A3 will result in an error. For document of size greater than the maximum allowed, you must first resize the image before adding it to the LEADTOOLS Plus OCR engine. The Professional and Advantage engines do not have a restriction on the image size.

Example

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

Copy Code

Public Sub AddMultiPageRasterImageExample()
      Dim imagesPath As String = LEAD_VARS.ImagesDir
      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(imagesPath, 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.Plus, 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, Nothing)

         ' 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("OCR 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"
End Class

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.Plus, 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, null);

         // 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";
}

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

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