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FrequencyFilterMaskCommand Class

Creates a mask filter to remove specific frequency components from the image. This command is available in the Imaging Pro and above toolkits.
public class FrequencyFilterMaskCommand : RasterCommand 
Public Class FrequencyFilterMaskCommand  
   Inherits RasterCommand 
public ref class FrequencyFilterMaskCommand : public RasterCommand 
  • 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.


Run the FrequencyFilterMaskCommand on an image.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
public void FrequencyFilterMaskCommandExample() 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, @"ImageProcessingDemo\FourierTransform.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); 
   FourierTransformInformation FTArray = new FourierTransformInformation(image); 
   // Apply FFT. 
   FastFourierTransformCommand command = new FastFourierTransformCommand(FTArray, FastFourierTransformCommandFlags.FastFourierTransform | FastFourierTransformCommandFlags.Gray); 
   FrequencyFilterMaskCommand FreqCommand = new FrequencyFilterMaskCommand(image, FTArray, false); 
   FastFourierTransformCommandFlags flags = FastFourierTransformCommandFlags.InverseFastFourierTransform | FastFourierTransformCommandFlags.Gray | FastFourierTransformCommandFlags.Scale | FastFourierTransformCommandFlags.Both; 
   FastFourierTransformCommand InvCommand = new FastFourierTransformCommand(FTArray, flags); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Core 
Public Sub FrequencyFilterMaskCommandExample() 
   Dim codecs As New RasterCodecs() 
   codecs.ThrowExceptionsOnInvalidImages = True 
   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "ImageProcessingDemo\\FourierTransform.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) 
   Dim FTArray As FourierTransformInformation = New FourierTransformInformation(leadImage) 
   ' Apply FFT. 
   Dim command As FastFourierTransformCommand = New FastFourierTransformCommand(FTArray, 
                                                                                FastFourierTransformCommandFlags.FastFourierTransform Or 
   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 
End Sub 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class 

Target Platforms

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Leadtools.ImageProcessing.Core Assembly