ExportPage(int) Method

Summary

Export the page at the specified index to a RasterImage object.

Syntax

Objective-C

C++

Java

public RasterImage ExportPage( 
   int pageIndex 
)

Overloads Function ExportPage( _ 
   ByVal pageIndex As Integer _ 
) As RasterImage

- (nullable LTRasterImage *)exportPageAtIndex:(NSUInteger)pageIndex 
                                        error:(NSError **)error

public RasterImage exportPage(int pageIndex) 
 
 
 
public RasterImage exportPage(int pageIndex)

RasterImage^ ExportPage(  
   int pageIndex 
)

Parameters

pageIndex
The zero-based index of the page to export.

Return Value

A RasterImage object containing a copy of the image data of the specified page.

Remarks

This method copies the image data to the created RasterImage object image. Therefore, after this method returns, there is no relationship between the returned value and the IOcrPage inside the OCR document. The returned RasterImage object will need to be disposed.

To export more than one page to a multipage RasterImage object, use ExportPages(int firstPageIndex, int lastPageIndex).

This method is identical to calling IOcrPage.GetRasterImage() on the page whose index is at pageIndex.

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.

Example

This example will add a page to an OCR document before exporting it back and saving it to disk

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Document.Writer; 
using Leadtools.Forms.Common; 
using Leadtools.ImageProcessing.Core; 
 
public void ExportPageToRasterImageExample() 
{ 
   string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); 
   string exportedFileName = Path.Combine(LEAD_VARS.ImagesDir, "OcrExported.jpg"); 
 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Create an instance of the engine 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
   { 
      // 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.OcrLEADRuntimeDir); 
 
      // Create an OCR document 
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) 
      { 
 
         // Add the image to the document 
         ocrDocument.Pages.AddPage(tifFileName, null); 
 
         // Export it back as a RasterImage 
         RasterImage image = ocrDocument.Pages.ExportPage(0); 
 
         // Save this image to disk 
         codecs.Save(image, exportedFileName, RasterImageFormat.Jpeg, 0); 
 
         // We need to dispose the image ourselves 
         image.Dispose(); 
      } 
 
      // 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:\LEADTOOLS21\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS21\Bin\Common\OcrLEADRuntime"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Ocr 
Imports Leadtools.Document.Writer 
Imports Leadtools.Forms 
Imports Leadtools.ImageProcessing.Core 
 
Public Sub ExportPageToRasterImageExample() 
   Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif") 
   Dim exportedFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "OcrExported.jpg") 
 
   Dim codecs As New RasterCodecs() 
 
   ' Create an instance of the engine 
   Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD) 
      ' 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.OcrLEADRuntimeDir) 
 
      ' Create an OCR document 
      Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument() 
 
         ' Add the image to the document 
         ocrDocument.Pages.AddPage(tifFileName, Nothing) 
 
         ' Export it back as a RasterImage 
         Dim image As RasterImage = ocrDocument.Pages.ExportPage(0) 
 
         ' Save this image to disk 
         codecs.Save(image, exportedFileName, RasterImageFormat.Jpeg, 0) 
 
         ' We need to dispose the image ourselves 
         image.Dispose() 
      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:\LEADTOOLS21\Resources\Images" 
   Public Const OcrLEADRuntimeDir As String = "C:\LEADTOOLS21\Bin\Common\OcrLEADRuntime" 
End Class