InvertedTextCommand Class

Finds and modifies areas of inverted text in a 1-bit black and white image. This command is available in the Document/Medical Toolkits.

Object Model

Syntax

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

public class InvertedTextCommand : Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

'Declaration
 
Public Class InvertedTextCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements Leadtools.ImageProcessing.IRasterCommand

'Usage
 
Dim instance As InvertedTextCommand

public sealed class InvertedTextCommand : Leadtools.ImageProcessing.IRasterCommand

function Leadtools.ImageProcessing.Core.InvertedTextCommand()

public ref class InvertedTextCommand : public Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

Remarks

This command finds and modifies areas of inverted text that are common in scanned text documents. Below is an example of inverted text:

Modifying the area of inverted text yields the following:
The behavior of this command can be modified by using an Event Handler that handles the InvertedTextCommandEventArgs.
This command works only on 1-bit black and white images.
If a region is selected, only the selected region will be changed by this method. If no region is selected, the whole image will be processed.
This command does not support signed data images.
This command does not support 32-bit grayscale images.

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

In Silverlight and Windows Phone versions of LEADTOOLS, this image processing command will fail if the image data for the RasterImage object is stored internally using a Silverlight WriteableBitmap object. For more information, refer to Image Processing Command Limitations in Silverlight.

Example

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

Public WithEvents invertedTextCommand_S1 As InvertedTextCommand
Public Sub InvertedTextCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Clean.tif"))

   ' Prepare the command
   invertedTextCommand_S1 = New InvertedTextCommand
   invertedTextCommand_S1.Flags = InvertedTextCommandFlags.UseDpi
   invertedTextCommand_S1.MaximumBlackPercent = 95
   invertedTextCommand_S1.MinimumBlackPercent = 70
   invertedTextCommand_S1.MinimumInvertHeight = 500
   invertedTextCommand_S1.MinimumInvertWidth = 5000

   invertedTextCommand_S1.Run(leadImage)

End Sub

Private Sub InvertedTextCommand_InvertedText_S1(ByVal sender As Object, ByVal e As InvertedTextCommandEventArgs) Handles invertedTextCommand_S1.InvertedText
   MessageBox.Show("Size " + "( " + e.BoundingRectangle.Left.ToString() + ", " + e.BoundingRectangle.Top.ToString() + ") - " + "( " + e.BoundingRectangle.Right.ToString() + ", " + e.BoundingRectangle.Bottom.ToString() + ")" + _
            Chr(13) + " Black Count " + e.BlackCount.ToString() + _
            Chr(13) + " White Count " + e.WhiteCount.ToString())
   e.Status = RemoveStatus.Remove
End Sub

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

public void InvertedTextCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Clean.tif"));

      // Prepare the command
      InvertedTextCommand command = new InvertedTextCommand();
      command.InvertedText  += new EventHandler<InvertedTextCommandEventArgs>(InvertedTextEvent_S1);
      command.Flags         = InvertedTextCommandFlags.UseDpi;
      command.MaximumBlackPercent = 95;
      command.MinimumBlackPercent = 70;
      command.MinimumInvertHeight = 500;
      command.MinimumInvertWidth  = 5000;

      command.Run(image);

   }

   private void InvertedTextEvent_S1(object sender, InvertedTextCommandEventArgs e)
   {

      MessageBox.Show("Size "           + "( " + e.BoundingRectangle.Left + ", " + e.BoundingRectangle.Top + ") - " + "( " + e.BoundingRectangle.Right + ", " + e.BoundingRectangle.Bottom + ")" +
         "\n Black Count " + e.BlackCount.ToString() + 
         "\n White Count " + e.WhiteCount.ToString());
      e.Status = RemoveStatus.Remove;
   }

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

function InvertedTextCommandExample() {
   var codecs = new Leadtools.Codecs.RasterCodecs();
   codecs.throwExceptionsOnInvalidImages = true;

   // Load the image
   var srcFileName = "Assets\\clean.tif";
   return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
      return codecs.loadAsync(Leadtools.LeadStreamFactory.create(loadFile));
   }).then(function (image) {
      // Prepare the command
      with (Leadtools.ImageProcessing.Core) {
         var command = new InvertedTextCommand();
         command.addEventListener("invertedtext", InvertedTextEvent_S1);
         command.flags = InvertedTextCommandFlags.useDpi;
         command.maximumBlackPercent = 95;
         command.minimumBlackPercent = 70;
         command.minimumInvertHeight = 500;
         command.minimumInvertWidth = 5000;

         command.run(image);
      }
   });
}

function InvertedTextEvent_S1(e) {
   console.error("Size " + "( " + e.boundingRectangle.x + ", " + e.boundingRectangle.y + ") - " + "( " + e.boundingRectangle.width + ", " + e.boundingRectangle.height + ")" +
      "\n Black Count " + e.blackCount.toString() +
      "\n White Count " + e.whiteCount.toString());
   e.status = Leadtools.ImageProcessing.Core.RemoveStatus.remove;
}

[TestMethod]
public async Task InvertedTextCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\Clean.tif";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Prepare the command
   InvertedTextCommand command = new InvertedTextCommand();
   command.InvertedText  += new EventHandler<InvertedTextCommandEventArgs>(InvertedTextEvent_S1);
   command.Flags         = InvertedTextCommandFlags.UseDpi;
   command.MaximumBlackPercent = 95;
   command.MinimumBlackPercent = 70;
   command.MinimumInvertHeight = 500;
   command.MinimumInvertWidth  = 5000;

   command.Run(image);

}

private void InvertedTextEvent_S1(object sender, InvertedTextCommandEventArgs e)
{

   Debug.WriteLine("Size "           + "( " + e.BoundingRectangle.X + ", " + e.BoundingRectangle.Y + ") - " + "( " + e.BoundingRectangle.Width + ", " + e.BoundingRectangle.Height + ")" +
      "\n Black Count " + e.BlackCount.ToString() + 
      "\n White Count " + e.WhiteCount.ToString());
   e.Status = RemoveStatus.Remove;
}

public void InvertedTextCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   InvertedTextCommand command = new InvertedTextCommand();
   command.InvertedText  += new EventHandler<InvertedTextCommandEventArgs>(InvertedTextEvent_S1);
   command.Flags         = InvertedTextCommandFlags.UseDpi;
   command.MaximumBlackPercent = 95;
   command.MinimumBlackPercent = 70;
   command.MinimumInvertHeight = 500;
   command.MinimumInvertWidth  = 5000;
   command.Run(image);

   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.CcittGroup4, 1);
   image.Dispose();
}

private void InvertedTextEvent_S1(object sender, InvertedTextCommandEventArgs e)
{

   Debug.WriteLine("Size "           + "( " + e.BoundingRectangle.Left + ", " + e.BoundingRectangle.Top + ") - " + "( " + e.BoundingRectangle.Right + ", " + e.BoundingRectangle.Bottom + ")" +
      "\n Black Count " + e.BlackCount.ToString() + 
      "\n White Count " + e.WhiteCount.ToString());
   e.Status = RemoveStatus.Remove;
}

Public Sub InvertedTextCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim command As InvertedTextCommand = New InvertedTextCommand()
   AddHandler command.InvertedText, AddressOf InvertedTextEvent_S1
   command.Flags = InvertedTextCommandFlags.UseDpi
   command.MaximumBlackPercent = 95
   command.MinimumBlackPercent = 70
   command.MinimumInvertHeight = 500
   command.MinimumInvertWidth = 5000
   command.Run(image)

   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.CcittGroup4, 1)
   image.Dispose()
End Sub

Private Sub InvertedTextEvent_S1(ByVal sender As Object, ByVal e As InvertedTextCommandEventArgs)

   Debug.WriteLine("Size " & "( " & e.BoundingRectangle.Left & ", " & e.BoundingRectangle.Top & ") - " & "( " & e.BoundingRectangle.Right & ", " _
                   & e.BoundingRectangle.Bottom & ")" & Constants.vbLf & " Black Count " & e.BlackCount.ToString() & Constants.vbLf & _
                   " White Count " & e.WhiteCount.ToString())
   e.Status = RemoveStatus.Remove
End Sub

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

InvertedTextCommand Members
Leadtools.ImageProcessing.Core Namespace
Cleaning Up 1-Bit Images
SmoothCommand Class
BorderRemoveCommand Class
LineRemoveCommand Class
InvertedPageCommand Class
DotRemoveCommand Class
HolePunchRemoveCommand Class
HighQualityRotateCommand Class
MinimumCommand Class
MaximumCommand Class
Leadtools.ImageProcessing.Effects.RegionHolesRemovalCommand