FrequencyFilterMaskCommand Class

Creates a mask filter to remove specific frequency components from the image. This command is available in the Raster Pro and above toolkits.

Object Model

Syntax

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

public class FrequencyFilterMaskCommand

'Declaration
 
Public Class FrequencyFilterMaskCommand

'Usage
 
Dim instance As FrequencyFilterMaskCommand

public sealed class FrequencyFilterMaskCommand

function Leadtools.ImageProcessing.Core.FrequencyFilterMaskCommand()

public ref class FrequencyFilterMaskCommand

Remarks

This command is used only when you are dealing with Fourier Transform methods.
The MaskImage will be treated as grayscale image. The (0,0) frequency located in mask image center; positive X harmonics located in the right half of the mask image and positive Y harmonics located in the lower half of the mask image. Mask image's dimensions must be equal to Data's dimensions.
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 32-bit grayscale images.
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 FrequencyFilterMaskCommandExample()
   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 FreqCommand As FrequencyFilterMaskCommand = New FrequencyFilterMaskCommand(leadImage, FTArray, False)
   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 FrequencyFilterMaskCommandExample()
   {
      // 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, RasterSizeFlags.Bicubic);

      sizecommand.Run(image);

      FourierTransformInformation FTArray = new FourierTransformInformation(image);
      // Apply FFT.
      FastFourierTransformCommand command = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.FastFourierTransform |  FastFourierTransformCommandFlags.Gray);
      command.Run(image);

      FrequencyFilterMaskCommand FreqCommand = new FrequencyFilterMaskCommand(image, FTArray, false);

      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 FrequencyFilterMaskCommandExample()
{
   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 FreqCommand = new FrequencyFilterMaskCommand(image, FTArray, false);

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

[TestMethod]
public async Task FrequencyFilterMaskCommandExample()
{
   // 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, RasterSizeFlags.Bicubic);

   sizecommand.Run(image);

   FourierTransformInformation FTArray = new FourierTransformInformation(image);
   // Apply FFT.
   FastFourierTransformCommand command = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.FastFourierTransform |  FastFourierTransformCommandFlags.Gray);
   command.Run(image);

   FrequencyFilterMaskCommand FreqCommand = new FrequencyFilterMaskCommand(image, FTArray, false);

   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