Module ij

Package ij.plugin

Class FFT

java.lang.Object

ij.plugin.FFT

All Implemented Interfaces:

Measurements, PlugIn

public class FFT
extends java.lang.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 java.lang.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

Constructor Summary

Constructors

Constructor	Description
FFT()

Method Summary

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(java.lang.String arg)	This method is called when the plugin is loaded.
static void	swapQuadrants(ImageProcessor ip)

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 java.lang.String fileName

Constructor Detail

FFT

public FFT()

Method Detail

run

public void run(java.lang.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

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.

swapQuadrants

public static void swapQuadrants(ImageProcessor ip)