#include <itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h>

Inheritance diagram for itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >:

Collaboration diagram for itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >:

Detailed Description

template<typename TImage>
class itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >

A multi-dimensional iterator templated over image type that walks pixels within a region and is specialized to keep track of its image index location.

This class is a specialization of ImageRegionConstIteratorWithIndex, adding method GetFrequencyBins to give the frequency bins corresponding to image indices, and GetFrequency to get the frequency of the bin. The frequency bins depends on the image size. The default assumes that the image to iterate over is the output of a forward FFT filter, where the first index corresponds to 0 frequency, and Nyquist Frequencies are in the middle, between positive and negative frequencies.

This class can be specialized further to iterate over other frequency layouts, for example shifted images (where 0 frequency is in the middle of the image, and Nyquist are in the border). For different layout, use other frequency iterator.

This iterator is for the frequency layout that results from applying a FFT (vnl or fftw) to an image. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

The frequency layout is assumed to be: where fs is frequency sampling, or frequency spacing (1.0 by default). If N is even: Nyquist frequency at index=N/2 is shared between + and - regions. <---------—positive f ------------—><---------—negative f-----------—> 0(DC) fs/N 2*fs/N ... (N/2 -1)*fs/N fs/2 -(N/2-1)*fs/N ... -2*fs/N -fs/N

Example: Size 6:

+ | -

0 <– DC Component (0 freq) 1 | 5 2 | 4 3 <– Shared between regions, unique Nyquist.

If N is odd: Nyquist frequency is not represented but there are simmetric largest frequencies at index=N/2, N/2 +1 <-------—positive f ------------—><---------—negative f--------------—> 0(DC) fs/N 2*fs/N ...... fs/2*(N-1)/N -fs/2*(N-1)/N ... -2*fs/N -fs/N

Example: Size 5:

+ | -

0 <– DC Component (0 freq) 1 | 4 2 | 3 <– Absolute Largest Frequency bins (+, -)

Please see ImageRegionConstIteratorWithIndex for more information.

See Also: ForwardFFTImageFilter

MORE INFORMATION: For a complete description of the ITK Image Iterators and their API, please see the Iterators chapter in the ITK Software Guide. The ITK Software Guide is available in print and as a free .pdf download from https://www.itk.org.

See Also: ImageRegionIteratorWithIndex; ImageConstIterator; ConditionalConstIterator; ConstNeighborhoodIterator; ConstShapedNeighborhoodIterator; ConstSliceIterator; CorrespondenceDataStructureIterator; FloodFilledFunctionConditionalConstIterator; FloodFilledImageFunctionConditionalConstIterator; FloodFilledImageFunctionConditionalIterator; FloodFilledSpatialFunctionConditionalConstIterator; FloodFilledSpatialFunctionConditionalIterator; ImageConstIterator; ImageConstIteratorWithIndex; ImageIterator; ImageIteratorWithIndex; ImageLinearConstIteratorWithIndex; ImageLinearIteratorWithIndex; ImageRandomConstIteratorWithIndex; ImageRandomIteratorWithIndex; ImageRegionConstIterator; ImageRegionConstIteratorWithIndex; ImageRegionExclusionConstIteratorWithIndex; ImageRegionExclusionIteratorWithIndex; ImageRegionIterator; ImageRegionIteratorWithIndex; ImageRegionReverseConstIterator; ImageRegionReverseIterator; ImageReverseConstIterator; ImageReverseIterator; ImageSliceConstIteratorWithIndex; ImageSliceIteratorWithIndex; NeighborhoodIterator; PathConstIterator; PathIterator; ShapedNeighborhoodIterator; SliceIterator; ImageConstIteratorWithIndex

Definition at line 114 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

Public Types
using	AccessorType = typename Superclass::AccessorType

using	FrequencyType = typename ImageType::SpacingType

using	FrequencyValueType = typename ImageType::SpacingValueType

using	ImageType = typename Superclass::ImageType

using	IndexType = typename Superclass::IndexType

using	InternalPixelType = typename Superclass::InternalPixelType

using	OffsetType = typename Superclass::OffsetType

using	PixelContainer = typename Superclass::PixelContainer

using	PixelContainerPointer = typename Superclass::PixelContainerPointer

using	PixelType = typename Superclass::PixelType

using	RegionType = typename Superclass::RegionType

using	Self = FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex

using	SizeType = typename Superclass::SizeType

using	Superclass = ImageRegionConstIteratorWithIndex< TImage >

Public Types inherited from itk::ImageRegionConstIteratorWithIndex< TImage >
using	AccessorType = typename Superclass::AccessorType

using	ImageType = typename Superclass::ImageType

using	IndexType = typename Superclass::IndexType

using	InternalPixelType = typename Superclass::InternalPixelType

using	OffsetType = typename Superclass::OffsetType

using	PixelContainer = typename Superclass::PixelContainer

using	PixelContainerPointer = typename Superclass::PixelContainerPointer

using	PixelType = typename Superclass::PixelType

using	RegionType = typename Superclass::RegionType

using	Self = ImageRegionConstIteratorWithIndex

using	SizeType = typename Superclass::SizeType

using	Superclass = ImageConstIteratorWithIndex< TImage >

Public Types inherited from itk::ImageConstIteratorWithIndex< TImage >
using	AccessorFunctorType = typename TImage::AccessorFunctorType

using	AccessorType = typename TImage::AccessorType

using	ImageType = TImage

using	IndexType = typename TImage::IndexType

using	IndexValueType = typename IndexType::IndexValueType

using	InternalPixelType = typename TImage::InternalPixelType

using	OffsetType = typename TImage::OffsetType

using	OffsetValueType = typename OffsetType::OffsetValueType

using	PixelContainer = typename TImage::PixelContainer

using	PixelContainerPointer = typename PixelContainer::Pointer

using	PixelType = typename TImage::PixelType

using	RegionType = typename TImage::RegionType

using	Self = ImageConstIteratorWithIndex

using	SizeType = typename TImage::SizeType

using	SizeValueType = typename SizeType::SizeValueType

Public Member Functions
	FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex ()

	FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex (const TImage *ptr, const RegionType &region)

	FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex (const Superclass &it)

IndexType	GetFrequencyBin () const


FrequencyType	GetFrequency () const

FrequencyValueType	GetFrequencyModuloSquare () const

virtual const IndexType &	GetZeroFrequencyIndex () const

virtual const FrequencyType &	GetFrequencyOrigin () const

virtual const FrequencyType &	GetFrequencySpacing () const

void	SetActualXDimensionIsOdd (bool value)

virtual bool	GetActualXDimensionIsOdd ()

virtual void	ActualXDimensionIsOddOn ()

virtual void	ActualXDimensionIsOddOff ()

Public Member Functions inherited from itk::ImageRegionConstIteratorWithIndex< TImage >
	ImageRegionConstIteratorWithIndex ()

	ImageRegionConstIteratorWithIndex (const TImage *ptr, const RegionType &region)

	ImageRegionConstIteratorWithIndex (const ImageConstIteratorWithIndex< TImage > &it)

Self &	operator++ ()

Self &	operator-- ()

Public Member Functions inherited from itk::ImageConstIteratorWithIndex< TImage >
PixelType	Get () const

const IndexType &	GetIndex () const

const RegionType &	GetRegion () const

void	GoToBegin ()

void	GoToReverseBegin ()

	ImageConstIteratorWithIndex ()

	ImageConstIteratorWithIndex (const Self &it)

	ImageConstIteratorWithIndex (const TImage *ptr, const RegionType &region)

bool	IsAtEnd () const

bool	IsAtReverseEnd () const

bool	operator!= (const Self &it) const

bool	operator< (const Self &it) const

bool	operator<= (const Self &it) const

Self &	operator= (const Self &it)

bool	operator== (const Self &it) const

bool	operator> (const Self &it) const

bool	operator>= (const Self &it) const

bool	Remaining ()

const PixelType &	Value () const

virtual	~ImageConstIteratorWithIndex ()=default

void	SetIndex (const IndexType &ind)

Private Member Functions

void	Init ()

Private Attributes
bool	m_ActualXDimensionIsOdd

FrequencyType	m_FrequencyOrigin

FrequencyType	m_FrequencySpacing

IndexType	m_ZeroFrequencyIndex

Additional Inherited Members
Static Public Member Functions inherited from itk::ImageConstIteratorWithIndex< TImage >
static unsigned int	GetImageDimension ()

Static Public Attributes inherited from itk::ImageConstIteratorWithIndex< TImage >
static constexpr unsigned int	ImageDimension = TImage::ImageDimension

Protected Attributes inherited from itk::ImageConstIteratorWithIndex< TImage >
const InternalPixelType *	m_Begin

IndexType	m_BeginIndex

const InternalPixelType *	m_End

IndexType	m_EndIndex

TImage::ConstWeakPointer	m_Image

OffsetValueType	m_OffsetTable [ImageDimension+1]

AccessorType	m_PixelAccessor

AccessorFunctorType	m_PixelAccessorFunctor

const InternalPixelType *	m_Position

IndexType	m_PositionIndex

RegionType	m_Region

bool	m_Remaining

Member Typedef Documentation

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::AccessorType = typename Superclass::AccessorType

Definition at line 132 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyType = typename ImageType::SpacingType

Definition at line 134 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyValueType = typename ImageType::SpacingValueType

Definition at line 135 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::ImageType = typename Superclass::ImageType

Definition at line 127 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::IndexType = typename Superclass::IndexType

Types inherited from the Superclass

Definition at line 123 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::InternalPixelType = typename Superclass::InternalPixelType

Definition at line 130 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::OffsetType = typename Superclass::OffsetType

Definition at line 125 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelContainer = typename Superclass::PixelContainer

Definition at line 128 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelContainerPointer = typename Superclass::PixelContainerPointer

Definition at line 129 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelType = typename Superclass::PixelType

Definition at line 131 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::RegionType = typename Superclass::RegionType

Definition at line 126 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Self = FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex

Standard class type alias.

Definition at line 119 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::SizeType = typename Superclass::SizeType

Definition at line 124 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

template<typename TImage>

using itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Superclass = ImageRegionConstIteratorWithIndex< TImage >

Definition at line 120 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

Constructor & Destructor Documentation

template<typename TImage>

itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex ( )

inline

Default constructor. Needed since we provide a cast constructor.

Definition at line 137 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().

template<typename TImage>

itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex	(	const TImage *	ptr,
		const RegionType &	region
	)

inline

Constructor establishes an iterator to walk a particular image and a particular region of that image.

Definition at line 145 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().

template<typename TImage>

itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex ( const Superclass & it )

inlineexplicit

Constructor that can be used to cast from an ImageIterator to an ImageRegionIteratorWithIndex. Many routines return an ImageIterator, but for a particular task, you may want an ImageRegionIteratorWithIndex. Rather than provide overloaded APIs that return different types of Iterators, itk returns ImageIterators and uses constructors to cast from an ImageIterator to a ImageRegionIteratorWithIndex.

Definition at line 157 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().

Member Function Documentation

template<typename TImage>

virtual void itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::ActualXDimensionIsOddOff ( )

virtual

Note that this method is independent of the region in the constructor. It takes into account the ImageInformation of the Image in the frequency domain. This iterator is for the frequency layout that results from applying a FFT and then ShiftFFT to center the zero frequency component. If your image has a different layout, use other frequency iterator. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

template<typename TImage>

virtual void itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::ActualXDimensionIsOddOn ( )

virtual

Note that this method is independent of the region in the constructor. It takes into account the ImageInformation of the Image in the frequency domain. This iterator is for the frequency layout that results from applying a FFT and then ShiftFFT to center the zero frequency component. If your image has a different layout, use other frequency iterator. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

template<typename TImage>

virtual bool itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetActualXDimensionIsOdd ( )

virtual

Note that this method is independent of the region in the constructor. It takes into account the ImageInformation of the Image in the frequency domain. This iterator is for the frequency layout that results from applying a FFT and then ShiftFFT to center the zero frequency component. If your image has a different layout, use other frequency iterator. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

template<typename TImage>

FrequencyType itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency ( ) const

inline

Note that this method is independent of the region in the constructor. It takes into account the ImageInformation of the Image in the frequency domain. This iterator is for the frequency layout that results from applying a FFT and then ShiftFFT to center the zero frequency component. If your image has a different layout, use other frequency iterator. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

Definition at line 193 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin(), itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencyOrigin, and itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencySpacing.

Referenced by itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyModuloSquare().

template<typename TImage>

IndexType itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin ( ) const

inline

Definition at line 168 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::ImageConstIteratorWithIndex< TImage >::m_PositionIndex, and itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_ZeroFrequencyIndex.

Referenced by itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency().

template<typename TImage>

FrequencyValueType itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyModuloSquare ( ) const

inline

Note that this method is independent of the region in the constructor. It takes into account the ImageInformation of the Image in the frequency domain. This iterator is for the frequency layout that results from applying a FFT and then ShiftFFT to center the zero frequency component. If your image has a different layout, use other frequency iterator. The default ImageInformation is: Origin = {{0}}, Spacing = {{1}}. In this case the frequency values will be in the range: [-1/2, 1/2] Hz Or [-pi, pi] rad/s To modify those ranges: a) Avoid modifying the origin. The origin index always corresponds to zero frequency after a FFT. The range should be always centered around zero. b) The spacing control the range of frequencies (always around zero). If the spacing is = {{0.5}} we get a frequency range of [-1/4, 1/4] or [-pi/2, pi/2].

Definition at line 207 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency().

template<typename TImage>

virtual const FrequencyType& itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyOrigin ( ) const

virtual

Origin of frequencies is zero for FFT output.

template<typename TImage>

virtual const FrequencyType& itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencySpacing ( ) const

virtual

This is the pixel width, or the bin size of the frequency in physical or world coordinates. SamplingFrequency = 1.0 / SpatialImageSpacing FrequencySpacing = SamplingFrequency / ImageSize FrequencySpacing = 1.0 / (SpatialImageSpacing * ImageSize) FrequencySpacing is computed at construction from the spacing of the input image, and cannot be modified.

template<typename TImage>

virtual const IndexType& itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetZeroFrequencyIndex ( ) const

virtual

Index with the zero frequency value. By default: ZeroFrequencyIndex = floor(sizeImage / 2); This is: N/2 if N even, (N - 1)/2 if N odd.

template<typename TImage>

void itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init ( )

inlineprivate

Calculate m_ZeroFrequencyIndex, and frequency spacing/origin. Called by constructors.

Definition at line 251 of file itkFrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex.h.

References itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencyOrigin, itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencySpacing, itk::ImageConstIteratorWithIndex< TImage >::m_Image, and itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_ZeroFrequencyIndex.

Referenced by itk::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyShiftedFFTLayoutImageRegionConstIteratorWithIndex().

template<typename TImage>