FrequencyFilterMaskCommand Class

Summary

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

Syntax

C++/CLI

Python

public class FrequencyFilterMaskCommand : RasterCommand

public ref class FrequencyFilterMaskCommand : public RasterCommand

class FrequencyFilterMaskCommand(RasterCommand):

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

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); 
 
   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); 
 
 
 
   FastFourierTransformCommandFlags flags = FastFourierTransformCommandFlags.InverseFastFourierTransform | FastFourierTransformCommandFlags.Gray | FastFourierTransformCommandFlags.Scale | FastFourierTransformCommandFlags.Both; 
   FastFourierTransformCommand InvCommand = new FastFourierTransformCommand(FTArray, flags); 
   InvCommand.Run(image); 
 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}