InsertPage(Int32,RasterImage,OcrProgressCallback) Method

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IOcrPage InsertPage( 
   int pageIndex,
   RasterImage image,
   OcrProgressCallback callback
)

'Declaration

Overloads Function InsertPage( _
   ByVal pageIndex As Integer, _
   ByVal image As RasterImage, _
   ByVal callback As OcrProgressCallback _
) As IOcrPage

'Usage

Dim instance As IOcrPageCollection
Dim pageIndex As Integer
Dim image As RasterImage
Dim callback As OcrProgressCallback
Dim value As IOcrPage
 
value = instance.InsertPage(pageIndex, image, callback)

IOcrPage InsertPage( 
   int pageIndex,
   RasterImage image,
   OcrProgressCallback callback
)

- (nullable LTOcrPage *)insertPageAtIndex:(NSUInteger)pageIndex
                                    image:(LTRasterImage *)image
                                    error:(NSError **)error

public OcrPage insertPage(int pageIndex,
                          RasterImage image,
                          OcrProgressListener callback)

function Leadtools.Forms.Ocr.IOcrPageCollection.InsertPage(Int32,RasterImage,OcrProgressCallback)( 
   pageIndex ,
   image ,
   callback 
)

IOcrPage^ InsertPage( 
   int pageIndex,
   RasterImage^ image,
   OcrProgressCallback^ callback
)

Parameters

pageIndex: The zero-based index at which image should be inserted.
image: The RasterImage object containing the page to insert.
callback: Optional callback to show operation progress.

Return Value

The IOcrPage object that define the newly inserted page.

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.

If image contains more than one page, then the current page as defined in RasterImage.Page is the one inserted to the OCR document.

To insert all or specific range of the pages of a multi-page RasterImage object to the OCR document, either iterate through the pages by changing to the value of RasterImage.Page to go from 1 to RasterImage.PageCount or use the InsertPages(int pageIndex, RasterImage image, int imageFirstPageNumber, int imageLastPageNumber, OcrProgressCallback callback) method.

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: If the value of the "Recognition.ShareOriginalImage" (only supported by the Advantage OCR engine) setting is supported and is set to true, then calling this method will store the reference image inside the page and the image reference must be kept alive as long as the IOcrPage is alive. In this mode, the original image reference can be obtained from the page using IOcrPage.GetRasterImage(OcrPageType.Original). Sharing the original image minimizes the memory used during OCR operations.

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 then insert in reverse order a group of RasterImage objects.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
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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 InsertPageFromRasterImageExample()
   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()

   ' 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()
         ' Loop through the images, insert them in the reverse order
         For i As Integer = 0 To 3
            Dim pageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, String.Format("Ocr{0}.tif", i + 1))
            Using image As RasterImage = codecs.Load(pageFileName)
               ocrDocument.Pages.InsertPage(0, image, Nothing)
            End Using
         Next

         ' 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 InsertPageFromRasterImageExample()
{
   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();

   // 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())
      {
         // Loop through the images, insert them in the reverse order
         for (int i = 0; i < 4; i++)
         {
            string pageFileName = Path.Combine(LEAD_VARS.ImagesDir, string.Format("Ocr{0}.tif", i + 1));
            using (RasterImage image = codecs.Load(pageFileName))
               ocrDocument.Pages.InsertPage(0, image, null);
         }

         // 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";
}

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

      
public async Task InsertPageFromRasterImageExample()
{
   string pdfFileName = "Ocr1.pdf";
   RasterCodecs codecs = new RasterCodecs();

   // Create an instance of the engine
   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, String.Empty, Tools.OcrEnginePath);

   // Create an OCR document
   IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument();

   // Loop through the images, insert them in the reverse order
   for(int i = 0; i < 4; i++)
   {
      string pageFileName = string.Format(@"Assets\Ocr{0}.tif", i + 1);
      StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(pageFileName);
      using (RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile)))
         ocrDocument.Pages.InsertPage(0, image, null);
   }

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

   // Save
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(pdfFileName, CreationCollisionOption.ReplaceExisting);
   await ocrDocument.SaveAsync(LeadStreamFactory.Create(saveFile), DocumentFormat.Pdf, null);

   // Shutdown the engine
   ocrEngine.Shutdown();

   codecs.Dispose();
}

Target Platforms

Reference

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