OcrPageType Enumeration

The type of the page's Leadtools.RasterImage to get.

Syntax

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

[SerializableAttribute()]
public enum OcrPageType : System.Enum, System.IComparable, System.IConvertible, System.IFormattable

'Declaration
 
<SerializableAttribute()>
Public Enum OcrPageType 
   Inherits System.Enum
   Implements System.IComparable, System.IConvertible, System.IFormattable

'Usage
 
Dim instance As OcrPageType

[SerializableAttribute()]
public enum OcrPageType : System.IComparable, System.IConvertible, System.IFormattable

Leadtools.Forms.Ocr.OcrPageType = function() { };
Leadtools.Forms.Ocr.OcrPageType.prototype = {

  LeadtoolsMemberMarker(replace me)
 };

[SerializableAttribute()]
public enum class OcrPageType : public System.Enum, System.IComparable, System.IConvertible, System.IFormattable

Members

Member	Description
Current	The current image, this image has the same properties as the original image used to create the page.
Processing	The processing image is created internally by the OCR engine and is passed to the zoning and recognition routines. This image is always black/white with uniform resolution.

Remarks

Each IOcrPage contains two versions of the image used to create it: an original (current) and an optional processing version. The processing version usually black/white and has uniform resolution (if the original image is FAX for example) and it gets passed to the internal OCR engine during the zoning and recognition process. The AutoPreprocess method also uses the B/W image to determine if the page is inverted, skewed or has an orientation; however, it applies the correction to both the current and processing images.

You can use IOcrPage.GetRasterImage(OcrPageType) to get a copy of either of these images.

You cannot set the processing image of a page; it is created automatically by the engine. This is why there is no IOcrPage.SetRasterImage(OcrPageType pageType) method.

If the original image is black and white and has uniform vertical and horizontal resolution, then the engine will not create a processing image, in other words, IOcrPage.GetRasterImage(OcrPageType.Current) and IOcrPage.GetRasterImage(OcrPageType.Processing) will return identical Leadtools.RasterImage objects.

If the original image has different horizontal and vertical resolution, such as a FAX image, the processing page will be have be resized to have uniform resolution.

The LEADTOOLS C# and VB .NET Main OCR demos (Examples\DotNet\CS\OcrMainDemo and Examples\DotNet\VB\OcrMainDemo) have an option in the page menu to toggle between showing the current (default) or processing image of each page.

Example

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

Copy Code

Private Shared Sub OcrPageTypeExample()
      Dim engineType As OcrEngineType = OcrEngineType.Professional
      Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(engineType, False)
         ocrEngine.Startup(Nothing, Nothing, Nothing, Nothing)
         Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument()
            Dim ocrPage As IOcrPage

            ' Load an image as 24-bpp
            Using image As RasterImage = ocrDocument.RasterCodecsInstance.Load( _
               Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"), _
               24, _
               CodecsLoadByteOrder.Bgr, _
               1, _
               1)
               ' Show the original image properties
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel)
               System.Diagnostics.Debug.Assert(image.BitsPerPixel = 24)

               ' Add it to the OCR engine
               ocrPage = ocrDocument.Pages.AddPage(image, Nothing)
            End Using

            ' Show the current OCR page size and color depth
            Using image As RasterImage = ocrPage.GetRasterImage(OcrPageType.Current)
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel)
               System.Diagnostics.Debug.Assert(image.BitsPerPixel = 24)
            End Using

            ' Show the processing OCR page size and color depth
            Using image As RasterImage = ocrPage.GetRasterImage(OcrPageType.Processing)
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel)
               System.Diagnostics.Debug.Assert(image.BitsPerPixel = 1)
            End Using
         End Using
      End Using
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

private static void OcrPageTypeExample()
   {
      OcrEngineType engineType = OcrEngineType.Professional;
      using(IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(engineType, false))
      {
         ocrEngine.Startup(null, null, null, null);
         using(IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument())
         {
            IOcrPage ocrPage;

            // Load an image as 24-bpp
            using(RasterImage image = ocrDocument.RasterCodecsInstance.Load(
               Path.Combine(LEAD_VARS.ImagesDir,"Ocr1.tif"),
               24,
               CodecsLoadByteOrder.Bgr,
               1,
               1))
            {
               // Show the original image properties
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
               System.Diagnostics.Debug.Assert(image.BitsPerPixel == 24);

               // Add it to the OCR engine
               ocrPage = ocrDocument.Pages.AddPage(image, null);
            }

            // Show the current OCR page size and color depth
            using(RasterImage image = ocrPage.GetRasterImage(OcrPageType.Current))
            {
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
               System.Diagnostics.Debug.Assert(image.BitsPerPixel == 24);
            }

            // Show the processing OCR page size and color depth
            using(RasterImage image = ocrPage.GetRasterImage(OcrPageType.Processing))
            {
               Console.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
               System.Diagnostics.Debug.Assert(image.BitsPerPixel == 1);
            }
         }
      }
   }

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

private static async void OcrPageTypeExample()
{
   OcrEngineType engineType = OcrEngineType.Advantage;
   IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(engineType, false);
   ocrEngine.Startup(null, null, String.Empty, Tools.OcrEnginePath);

   IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument();

   IOcrPage ocrPage;

   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(@"Assets\Ocr1.tif");
   using (RasterImage image = await ocrDocument.RasterCodecsInstance.LoadAsync(LeadStreamFactory.Create(loadFile)))
   {
      // Convert the image to 24-bpp
      ColorResolutionCommand command = new ColorResolutionCommand(ColorResolutionCommandMode.InPlace, 24, RasterByteOrder.Bgr, RasterDitheringMethod.None, ColorResolutionCommandPaletteFlags.None, null);
      command.Run(image);

      // Show the original image properties
      Debug.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
      System.Diagnostics.Debug.Assert(image.BitsPerPixel == 24);

      // Add it to the OCR engine
      ocrPage = ocrDocument.Pages.AddPage(image, null);
   }

   // Show the current OCR page size and color depth
   using (RasterImage image = ocrPage.GetRasterImage(OcrPageType.Current))
   {
      Debug.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
      System.Diagnostics.Debug.Assert(image.BitsPerPixel == 24);
   }

   // Show the processing OCR page size and color depth
   using (RasterImage image = ocrPage.GetRasterImage(OcrPageType.Processing))
   {
      Debug.WriteLine("Original size is {0} by {1} at {2} bits/pixel", image.ImageWidth, image.ImageHeight, image.BitsPerPixel);
      System.Diagnostics.Debug.Assert(image.BitsPerPixel == 1);
   }

   // Shutdown the engine
   ocrEngine.Shutdown();
}

Inheritance Hierarchy

System.Object
   System.ValueType
      System.Enum
         Leadtools.Forms.Ocr.OcrPageType

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

Leadtools.Forms.Ocr Namespace
IOcrDocument.GetRasterImage
IOcrPage.SetRasterImage
Programming with Leadtools .NET OCR
Working with OCR Pages