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InvertedPageCommand Class
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Leadtools.ImageProcessing.Core Namespace : InvertedPageCommand Class



Checks and auto-corrects an inverted image. Supported in Silverlight, Windows Phone 7

Object Model

InvertedPageCommand Class

Syntax

Visual Basic (Declaration) 
Public Class InvertedPageCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As InvertedPageCommand
C# 
public class InvertedPageCommand : Leadtools.ImageProcessing.RasterCommand, IRasterCommand 
C++/CLI 
public ref class InvertedPageCommand : public Leadtools.ImageProcessing.RasterCommand, IRasterCommand 

Example

This example will show how to use the InvertedPageCommand class to check and auto-correct inverted images.

Visual BasicCopy Code
Public Sub InvertedPageCommandExample()
   Dim codecs As New RasterCodecs()

   ' Get an image
   Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1.tif")
   Dim invertedImageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_Inverted.tif")
   Dim nonInvertedImageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_NonInverted.tif")

   Dim image As RasterImage = codecs.Load(tifFileName)

   ' The images should be non-inverted at the beginning, check
   Dim invertedPage As New InvertedPageCommand(InvertedPageCommandFlags.NoProcess)
   invertedPage.Run(image)
   Console.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted)

   ' Invert the image
   Dim invert As New InvertCommand()
   invert.Run(image)

   codecs.Save(image, invertedImageFileName, image.OriginalFormat, image.BitsPerPixel)

   ' Check again
   invertedPage.Run(image)
   Console.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted)

   ' Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process
   invertedPage.Run(image)

   ' Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess
   invertedPage.Run(image)
   Console.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted)
   codecs.Save(image, nonInvertedImageFileName, image.OriginalFormat, image.BitsPerPixel)

   image.Dispose()

   codecs.Dispose()
End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
C#Copy Code
public void InvertedPageCommandExample()
   {
      RasterCodecs codecs = new RasterCodecs();

      // Get an image
      string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1.tif");
      string invertedImageFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_Inverted.tif");
      string nonInvertedImageFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_NonInverted.tif");

      RasterImage image = codecs.Load(tifFileName);

      // The images should be non-inverted at the beginning, check
      InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NoProcess);
      invertedPage.Run(image);
      Console.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted);

      // Invert the image
      InvertCommand invert = new InvertCommand();
      invert.Run(image);

      codecs.Save(image, invertedImageFileName, image.OriginalFormat, image.BitsPerPixel);

      // Check again
      invertedPage.Run(image);
      Console.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted);

      // Now run the command to un-invert the image
      invertedPage.Flags = InvertedPageCommandFlags.Process;
      invertedPage.Run(image);

      // Now check the image again
      invertedPage.Flags = InvertedPageCommandFlags.NoProcess;
      invertedPage.Run(image);
      Console.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted);
      codecs.Save(image, nonInvertedImageFileName, image.OriginalFormat, image.BitsPerPixel);

      image.Dispose();

      codecs.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
SilverlightCSharpCopy Code
public void InvertedPageCommandExample(RasterImage image, Stream outStream1, Stream outStream2)
{
   // The images should be non-inverted at the beginning, check
   InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NoProcess);
   invertedPage.Run(image);
   Debug.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted);
   // Invert the image
   InvertCommand invert = new InvertCommand();
   invert.Run(image);

   RasterCodecs codecs = new RasterCodecs();
   // save image to "ocr1_Inverted.tif";
   codecs.Save(image, outStream1, image.OriginalFormat, image.BitsPerPixel);

   // Check again
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted);

   // Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process;
   invertedPage.Run(image);

   // Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess;
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted);

   // save result image to "ocr1_NonInverted.tif"
   codecs.Save(image, outStream2, RasterImageFormat.CcittGroup4, 1);

   image.Dispose();
}
SilverlightVBCopy Code
Public Sub InvertedPageCommandExample(ByVal image As RasterImage, ByVal outStream1 As Stream, ByVal outStream2 As Stream)
   ' The images should be non-inverted at the beginning, check
   Dim invertedPage As InvertedPageCommand = New InvertedPageCommand(InvertedPageCommandFlags.NoProcess)
   invertedPage.Run(image)
   Debug.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted)
   ' Invert the image
   Dim invert As InvertCommand = New InvertCommand()
   invert.Run(image)

   Dim codecs As RasterCodecs = New RasterCodecs()
   ' save image to "ocr1_Inverted.tif";
   codecs.Save(image, outStream1, image.OriginalFormat, image.BitsPerPixel)

   ' Check again
   invertedPage.Run(image)
   Debug.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted)

   ' Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process
   invertedPage.Run(image)

   ' Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess
   invertedPage.Run(image)
   Debug.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted)

   ' save result image to "ocr1_NonInverted.tif"
   codecs.Save(image, outStream2, RasterImageFormat.CcittGroup4, 1)

   image.Dispose()
End Sub

Remarks

An inverted Leadtools.RasterImage is an image that has text or other objects in high contrast color on a low contrast background, for example white text on black background. This command can check whether an image is inverted as well as auto-correct it.

This command can only detect an entire image. To search for and correct specific inverted areas or regions in an image, use the InvertedTextCommand.

A common source of inverted images are black and white images saved with a non-standard palette by some applications.

This command does not support signed data images.

For more information, refer to Cleaning Up 1-Bit Images.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Core.InvertedPageCommand

Requirements

Target Platforms: Silverlight 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)

See Also