FrequencyFilterCommand Class

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

Object Model

Syntax

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

public class FrequencyFilterCommand

'Declaration
 
Public Class FrequencyFilterCommand

'Usage
 
Dim instance As FrequencyFilterCommand

public sealed class FrequencyFilterCommand

function Leadtools.ImageProcessing.Core.FrequencyFilterCommand()

public ref class FrequencyFilterCommand

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.

Example

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

Public Sub FrequencyFilterCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

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

End Sub

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

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

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "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);
      LeadRect rcRect = new LeadRect(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);

   }

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

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

   // Load the image
   var srcFileName = "Assets\\Image1.cmp";
   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) {
         // Resize the image to make sure the image's dimensions are power of two.
         var sizecommand = new Leadtools.ImageProcessing.SizeCommand(256, 256, Leadtools.RasterSizeFlags.bicubic);
         
         sizecommand.run(image);

         var FTArray = new FourierTransformInformation(image);
         // Apply FFT.
         var command = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.fastFourierTransform |  FastFourierTransformCommandFlags.gray);

         command.run(image);
         var rcRect = Leadtools.LeadRectHelper.create(0, 0, image.width / 2, image.height / 2);
         var FreqCommand = new FrequencyFilterCommand(FTArray, rcRect, FrequencyFilterCommandFlags.insideX | FrequencyFilterCommandFlags.insideY);

         var InvCommand = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.inverseFastFourierTransform |  FastFourierTransformCommandFlags.gray | FastFourierTransformCommandFlags.scale | FastFourierTransformCommandFlags.both);
         InvCommand.run(image);
      }
   });
}

[TestMethod]
public async Task FrequencyFilterCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // 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);
   LeadRect rcRect = LeadRectHelper.Create(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);

}

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