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FrequencyFilterMaskCommand Class
See Also  Members   Example 
Leadtools.ImageProcessing.Core Namespace : 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 (Declaration) 
Public Class FrequencyFilterMaskCommand
Visual Basic (Usage)Copy Code
Dim instance As FrequencyFilterMaskCommand
C# 
public class FrequencyFilterMaskCommand
C++/CLI 
public ref class FrequencyFilterMaskCommand

Example

Run the FrequencyFilterMaskCommand on an image.

Visual BasicCopy Code
Public Sub FrequencyFilterMaskCommandExample()
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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)

   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void FrequencyFilterMaskCommandExample() 
{ 
   // Load an image 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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); 
 
   RasterCodecs.Shutdown(); 
}

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.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.Core.FrequencyFilterMaskCommand

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