FFT (ImageJ API)

java.lang.Object
- ij.plugin.FFT

All Implemented Interfaces:

Measurements, PlugIn
```
public class FFT
extends Object
implements PlugIn, Measurements
```
This class implements the FFT, Inverse FFT and Redisplay Power Spectrum commands in the Process/FFT submenu. It is based on Arlo Reeves' Pascal implementation of the Fast Hartley Transform from NIH Image (http://imagej.nih.gov/ij/docs/ImageFFT/). The Fast Hartley Transform was restricted by U.S. Patent No. 4,646,256, but was placed in the public domain by Stanford University in 1995 and is now freely available. Version 2008-08-25 inverse transform: mask is always symmetrized

Field Summary

Fields
Modifier and Type Field Description

static boolean displayComplex

static boolean displayFHT

static boolean displayRawPS

static String fileName
- Fields inherited from interface ij.measure.Measurements
  ADD_TO_OVERLAY, ALL_STATS, AREA, AREA_FRACTION, CENTER_OF_MASS, CENTROID, CIRCULARITY, ELLIPSE, FERET, INTEGRATED_DENSITY, INVERT_Y, KURTOSIS, LABELS, LIMIT, MAX_STANDARDS, MEAN, MEDIAN, MIN_MAX, MODE, NaN_EMPTY_CELLS, PERIMETER, RECT, SCIENTIFIC_NOTATION, SHAPE_DESCRIPTORS, SKEWNESS, SLICE, STACK_POSITION, STD_DEV

Fields
Modifier and Type	Field	Description
`static boolean`	`displayComplex`
`static boolean`	`displayFHT`
`static boolean`	`displayRawPS`
`static String`	`fileName`

Constructor Summary

Constructors
Constructor Description

FFT()

Constructors
Constructor	Description
`FFT()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`filter(ImagePlus imp, ImagePlus filter)`	Version of filter() that accepts an ImagePlus for the filter.
`static void`	`filter(ImagePlus imp, ImageProcessor filter)`	Does frequency domain fitering of the speciified image
`static ImagePlus`	`forward(ImagePlus imp)`	Performs a forward FHT transform.
`static ImagePlus`	`inverse(ImagePlus imp)`	Performs an inverse FHT transform.
`static void`	`multiply(ImagePlus imp, ImageProcessor filter)`	Multiplies a Fourier domain image by a filter
`void`	`run(String arg)`	This method is called when the plugin is loaded.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - displayRawPS
```
public static boolean displayRawPS
```
  - displayFHT
```
public static boolean displayFHT
```
  - displayComplex
```
public static boolean displayComplex
```
  - fileName
```
public static String fileName
```
- Constructor Detail
  - FFT
```
public FFT()
```
- Method Detail
  - forward
```
public static ImagePlus forward(ImagePlus imp)
```
    Performs a forward FHT transform.
    
    Parameters:
    
    imp - A spatial domain image, which is not modified
    
    Returns:
    
    A frequency domain version of the input image
    
    See Also:
    
    filter(ij.ImagePlus, ij.process.ImageProcessor), inverse(ij.ImagePlus)
  - multiply
```
public static void multiply(ImagePlus imp,
                            ImageProcessor filter)
```
    Multiplies a Fourier domain image by a filter
    
    Parameters:
    
    imp - A frequency domain image, which is modified.
    
    filter - The filter, 32-bits (0-1) or 8-bits (0-255)
    
    See Also:
    
    forward(ij.ImagePlus), inverse(ij.ImagePlus), filter(ij.ImagePlus, ij.process.ImageProcessor)
  - inverse
```
public static ImagePlus inverse(ImagePlus imp)
```
    Performs an inverse FHT transform.
    
    Parameters:
    
    imp - A frequency domain image
    
    Returns:
    
    A spatial domain version of the input image
    
    See Also:
    
    forward(ij.ImagePlus), filter(ij.ImagePlus, ij.process.ImageProcessor)
  - filter
```
public static void filter(ImagePlus imp,
                          ImageProcessor filter)
```
    Does frequency domain fitering of the speciified image
    
    Parameters:
    
    imp - The image to be filtered.
    
    filter - The filter, 32-bits (0-1) or 8-bits (0-255)
    
    See Also:
    
    forward(ij.ImagePlus), multiply(ij.ImagePlus, ij.process.ImageProcessor), inverse(ij.ImagePlus)
  - filter
```
public static void filter(ImagePlus imp,
                          ImagePlus filter)
```
    Version of filter() that accepts an ImagePlus for the filter.
  - run
```
public void run(String arg)
```
    Description copied from interface: PlugIn
    
    This method is called when the plugin is loaded. 'arg', which may be blank, is the argument specified for this plugin in IJ_Props.txt.
    
    Specified by:
    
    run in interface PlugIn

Class FFT

Field Summary

Fields inherited from interface ij.measure.Measurements

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

displayRawPS

displayFHT

displayComplex

fileName

Constructor Detail

FFT

Method Detail

forward

multiply

inverse

filter

filter

run