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FrequencyFilterCommand Class
See Also  Members   Example 
Leadtools.ImageProcessing.Core Namespace : FrequencyFilterCommand Class




Filters the frequency harmonics data produced by a Fourier Transform method using a range rectangle.

Object Model


Syntax

Visual Basic (Declaration) 
Public Class FrequencyFilterCommand
Visual Basic (Usage)Copy Code
Dim instance As FrequencyFilterCommand
C# 
public class FrequencyFilterCommand
Managed Extensions for C++ 
public __gc class FrequencyFilterCommand
C++/CLI 
public ref class FrequencyFilterCommand

Example

Visual BasicCopy Code
ImageProcessing.Core.FrequencyFilterCommand
   Public Sub FrequencyFilterCommandExample()
      RasterCodecs.Startup()
      Dim codecs As New RasterCodecs()
      codecs.ThrowExceptionsOnInvalidImages = True

      Dim leadImage As RasterImage = codecs.Load("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Master.jpg")

      ' Prepare the command
      ' Resize the image to make sure the image's dimensions are power of two.
      Dim sizecommand As SizeCommand = New SizeCommand(256, 256, RasterSizeFlags.Bicubic)

      sizecommand.Run(leadImage)

      Dim FTArray As FourierTransformInformation = New FourierTransformInformation(leadImage)
      ' Apply FFT.
      Dim command As FastFourierTransformCommand = New FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.FastFourierTransform Or FastFourierTransformCommandFlags.Gray)


      command.Run(leadImage)
      Dim rcRect As Rectangle = New Rectangle(0, 0, leadImage.Width \ 2, leadImage.Height \ 2)
      Dim FreqCommand As FrequencyFilterCommand = New FrequencyFilterCommand(FTArray, rcRect, FrequencyFilterCommandFlags.InsideX Or FrequencyFilterCommandFlags.OutsideY)

      Dim InvCommand As FastFourierTransformCommand = New FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.InverseFastFourierTransform Or FastFourierTransformCommandFlags.Gray Or FastFourierTransformCommandFlags.Scale Or FastFourierTransformCommandFlags.Both)

      InvCommand.Run(leadImage)

      RasterCodecs.Shutdown()
   End Sub
C#Copy Code
ImageProcessing.Core.FrequencyFilterCommand 
      public void FrequencyFilterCommandExample() 
      { 
         // Load an image 
         RasterCodecs.Startup(); 
         RasterCodecs codecs = new RasterCodecs(); 
         codecs.ThrowExceptionsOnInvalidImages = true; 
 
         RasterImage image = codecs.Load(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Master.jpg"); 
 
         // Prepare the command 
         // Resize the image to make sure the image's dimensions are power of two. 
         SizeCommand sizecommand = new SizeCommand(256, 256, Leadtools.RasterSizeFlags.Bicubic); 
 
         sizecommand.Run(image); 
 
         FourierTransformInformation FTArray = new FourierTransformInformation(image); 
         // Apply FFT. 
         FastFourierTransformCommand command = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.FastFourierTransform |  FastFourierTransformCommandFlags.Gray); 
 
         command.Run(image); 
         Rectangle rcRect = new Rectangle(0, 0, image.Width / 2, image.Height / 2); 
         FrequencyFilterCommand FreqCommand = new FrequencyFilterCommand(FTArray, rcRect, FrequencyFilterCommandFlags.InsideX | FrequencyFilterCommandFlags.InsideY); 
 
         FastFourierTransformCommand InvCommand = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.InverseFastFourierTransform |  FastFourierTransformCommandFlags.Gray | FastFourierTransformCommandFlags.Scale | FastFourierTransformCommandFlags.Both); 
         InvCommand.Run(image); 
 
         RasterCodecs.Shutdown(); 
      }

Remarks

  • This command is used only when working with Fourier Transform methods.
  • This command does not support 12 and 16-bit grayscale and 48 and 64-bit color images. If the image is 12 and 16-bit grayscale and 48 and 64-bit color, the command will not threw an exception.
  • This command does not support signed images.
For more information, refer to Removing Noise.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.Core.FrequencyFilterCommand

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also