boofcv.alg.transform.fft

Class GDiscreteFourierTransformOps

java.lang.Object

boofcv.alg.transform.fft.GDiscreteFourierTransformOps

public class GDiscreteFourierTransformOps
extends Object

Implementation of functions in DiscreteFourierTransformOps which are image type agnostic

Author:

Peter Abeles

Constructor Summary

Constructors

Constructor and Description
GDiscreteFourierTransformOps()

Method Summary

Methods

Modifier and Type	Method and Description
static <T extends ImageFloat,W extends ImageInterleaved> DiscreteFourierTransform<T,W>	createTransform(ImageDataType type) Creates a DiscreteFourierTransform for the specified type.
static void	magnitude(ImageInterleaved transform, ImageFloat magnitude) Computes the magnitude of the complex image: magnitude = sqrt( real2 + imaginary2 )
static void	multiplyComplex(ImageInterleaved complexA, ImageInterleaved complexB, ImageInterleaved complexC) Performs element-wise complex multiplication between two complex images.
static void	multiplyRealComplex(ImageFloat realA, ImageInterleaved complexB, ImageInterleaved complexC) Performs element-wise complex multiplication between a real image and a complex image.
static void	phase(ImageInterleaved transform, ImageFloat phase) Computes the phase of the complex image: phase = atan2( imaginary , real )
static void	realToComplex(ImageFloat real, ImageInterleaved complex) Converts a regular image into a complex interleaved image with the imaginary component set to zero.
static void	shiftZeroFrequency(ImageInterleaved transform, boolean forward) Moves the zero-frequency component into the image center (width/2,height/2).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GDiscreteFourierTransformOps

public GDiscreteFourierTransformOps()

Method Detail

createTransform

public static <T extends ImageFloat,W extends ImageInterleaved> DiscreteFourierTransform<T,W> createTransform(ImageDataType type)

Creates a DiscreteFourierTransform for the specified type.

Parameters:

type - Image data type

Returns:

DiscreteFourierTransform

See Also:

DiscreteFourierTransform

shiftZeroFrequency

public static void shiftZeroFrequency(ImageInterleaved transform,
                      boolean forward)

Moves the zero-frequency component into the image center (width/2,height/2). This function can be called to undo the transform.

Parameters:

transform - the DFT which is to be shifted.

forward - If true then it does the shift in the forward direction. If false then it undoes the transforms.

magnitude

public static void magnitude(ImageInterleaved transform,
             ImageFloat magnitude)

Computes the magnitude of the complex image:
magnitude = sqrt( real² + imaginary² )

Parameters:

transform - (Input) Complex interleaved image

magnitude - (Output) Magnitude of image

phase

public static void phase(ImageInterleaved transform,
         ImageFloat phase)

Computes the phase of the complex image:
phase = atan2( imaginary , real )

Parameters:

transform - (Input) Complex interleaved image

phase - (output) Phase of image

realToComplex

public static void realToComplex(ImageFloat real,
                 ImageInterleaved complex)

Converts a regular image into a complex interleaved image with the imaginary component set to zero.

Parameters:

real - (Input) Regular image.

complex - (Output) Equivalent complex image.

multiplyRealComplex

public static void multiplyRealComplex(ImageFloat realA,
                       ImageInterleaved complexB,
                       ImageInterleaved complexC)

Performs element-wise complex multiplication between a real image and a complex image.

Parameters:

realA - (Input) Regular image

complexB - (Input) Complex image

complexC - (Output) Complex image

multiplyComplex

public static void multiplyComplex(ImageInterleaved complexA,
                   ImageInterleaved complexB,
                   ImageInterleaved complexC)

Performs element-wise complex multiplication between two complex images.

Parameters:

complexA - (Input) Complex image

complexB - (Input) Complex image

complexC - (Output) Complex image