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InvertedTextCommand Class

Summary

Finds and modifies areas of inverted text in a 1-bit black and white image.

Syntax
C#
VB
Objective-C
C++
Java
public class InvertedTextCommand : RasterCommand 
Public Class InvertedTextCommand  
   Inherits RasterCommand 
@interface LTInvertedTextCommand : LTRasterCommand 
public class InvertedTextCommand extends RasterCommand 
public ref class InvertedTextCommand : public RasterCommand   

Remarks

This command is available in the Document/Medical Toolkits.

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

    invert1.jpg
    Modifying the area of inverted text yields the following:
    invert2.jpg

  • 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.

Example

Runs the InvertedTextCommand on an image.

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Core; 
 
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"; 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Core 
 
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 
c#[Silverlight C# Example] 
using Leadtools; 
using Leadtools.Examples; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Core; 
 
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; 
} 
vb[Silverlight VB Example] 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Core 
 
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

Help Version 20.0.2020.4.3
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Leadtools.ImageProcessing.Core Assembly