FftGrid Class

The FftGrid is used as an intermediate step in FFT processing. It transforms a grayscale image into the FFT domain, and is required prior to all FFT filters.

Inheritance Hierarchy

SystemObject
Atalasoft.Imaging.ImageProcessing.FftFftGrid

Namespace: Atalasoft.Imaging.ImageProcessing.Fft
Assembly: Atalasoft.dotImage (in Atalasoft.dotImage.dll) Version: 11.4.0.9.0.377 (.NET 4.5.2, x86)

Syntax

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public class FftGrid : IDisposable

Public Class FftGrid
	Implements IDisposable

The FftGrid type exposes the following members.

Constructors

	Name	Description
	FftGrid	Initializes a new instance of the FftGrid class.
	FftGrid(AtalaImage)	Initializes a new instance of the FftGrid class

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Properties

	Name	Description
	Height	Gets the height of this FftGrid.
	Image	Gets or sets the AtalaImage associated with this FftGrid.
	Width	Gets the width of this FftGrid.

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Methods

	Name	Description
	Dispose	Cleans up unmanaged resources.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Finalizes an instance of the FftGrid class. (Overrides ObjectFinalize.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetNextPowerOfTwo	A helper function that retrieves the next power of two (128, 256, 512, 1024, etc). x^2
	GetProcessedImage	Returns the processed image from the frequency domain.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Remarks

When using the Grid as the intermediate step, multiple FFT filters can be applied. Each FFT Command has an ApplyToGrid method that uses an FftGrid to process. Once the image has completed processing, be sure to return the changed image with the GetProcessedImage method.

Examples

FftGrid Example (C#)

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// Load an 8-bit grayscale image.
AtalaImage image = new AtalaImage(@"D:\Test Images\JPG\8-bit alpha mask.jpg");

// Resize the image so its width and height are a power of 2.
Size newSize = new Size(FftGrid.GetNextPowerOfTwo(image.Width), FftGrid.GetNextPowerOfTwo(image.Height));
ResampleCommand resample = new ResampleCommand(newSize);
AtalaImage temp = resample.ApplyToImage(image);
image.Dispose();

// Create an FftGrid from the image and apply a filter to it.
FftGrid grid = new FftGrid(temp);
ButterworthHighPassFftCommand cmd = new ButterworthHighPassFftCommand(1.2, 2.4);
cmd.ApplyToGrid(grid);

// Get the resulting image.
this.viewer.Image = grid.GetProcessedImage();
temp.Dispose();

FftGrid Example (Visual Basic)

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' Load an 8-bit grayscale image.
Dim image As AtalaImage =  New AtalaImage("D:\Test Images\JPG\8-bit alpha mask.jpg") 

' Resize the image so its width and height are a power of 2.
Dim NewSize As Size =  New Size(FftGrid.GetNextPowerOfTwo(image.Width),FftGrid.GetNextPowerOfTwo(image.Height)) 
Dim resample As ResampleCommand =  New ResampleCommand(NewSize) 
Dim temp As AtalaImage =  resample.ApplyToImage(image) 
image.Dispose()

' Create an FftGrid from the image and apply a filter to it.
Dim grid As FftGrid =  New FftGrid(temp) 
Dim cmd As ButterworthHighPassFftCommand =  New ButterworthHighPassFftCommand(1.2,2.4) 
cmd.ApplyToGrid(grid)

' Get the resulting image.
Me.viewer.Image = grid.GetProcessedImage()
temp.Dispose()

Reference

Atalasoft.Imaging.ImageProcessing.Fft Namespace