 |
ITK
5.2.0
Insight Toolkit
|
|
ITK
5.2.0
Insight Toolkit
|
#include <itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h>
Inheritance diagram for itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >: Collaboration diagram for itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >: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 > | |
| TImage::ConstWeakPointer | m_Image |
| IndexType | m_PositionIndex |
| IndexType | m_BeginIndex |
| IndexType | m_EndIndex |
| RegionType | m_Region |
| OffsetValueType | m_OffsetTable [ImageDimension+1] |
| const InternalPixelType * | m_Position |
| const InternalPixelType * | m_Begin |
| const InternalPixelType * | m_End |
| bool | m_Remaining |
| AccessorType | m_PixelAccessor |
| AccessorFunctorType | m_PixelAccessorFunctor |
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 symmetric 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.
Definition at line 115 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::AccessorType = typename Superclass::AccessorType |
Definition at line 133 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyType = typename ImageType::SpacingType |
Definition at line 135 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyValueType = typename ImageType::SpacingValueType |
Definition at line 136 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::ImageType = typename Superclass::ImageType |
Definition at line 128 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::IndexType = typename Superclass::IndexType |
Types inherited from the Superclass
Definition at line 124 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::InternalPixelType = typename Superclass::InternalPixelType |
Definition at line 131 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::OffsetType = typename Superclass::OffsetType |
Definition at line 126 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelContainer = typename Superclass::PixelContainer |
Definition at line 129 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelContainerPointer = typename Superclass::PixelContainerPointer |
Definition at line 130 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::PixelType = typename Superclass::PixelType |
Definition at line 132 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::RegionType = typename Superclass::RegionType |
Definition at line 127 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Self = FrequencyFFTLayoutImageRegionConstIteratorWithIndex |
Standard class type alias.
Definition at line 120 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::SizeType = typename Superclass::SizeType |
Definition at line 125 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
| using itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Superclass = ImageRegionConstIteratorWithIndex<TImage> |
Definition at line 121 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
|
inline |
Default constructor. Needed since we provide a cast constructor.
Definition at line 138 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
inline |
Constructor establishes an iterator to walk a particular image and a particular region of that image.
Definition at line 146 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
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 158 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
|
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
|
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
|
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 209 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin(), itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencyOrigin, and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencySpacing.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyModuloSquare().
|
inline |
Definition at line 170 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_LargestPositiveFrequencyIndex, itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_MaxIndex, itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_MinIndex, and itk::ImageConstIteratorWithIndex< TImage >::m_PositionIndex.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency().
|
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 223 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency().
|
virtual |
Origin of frequencies is zero for FFT output.
|
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.
|
virtual |
Index corresponding to the first highest frequency (Nyquist) after a FFT transform. If the size of the image is even, the Nyquist frequency = fs/2 is unique and shared between positive and negative frequencies. (Even Size) LargestPositiveFrequencyIndex = originIndex + N / 2 If odd, Nyquist frequency is not represented, but there is still a largest frequency at this index = fs/2 * (N-1)/N. (Odd Size) LargestPositiveFrequencyIndex = originIndex + (N + 1) / 2
|
virtual |
Default to UpperIndex of the largest possible Region.
|
virtual |
Default to first index of the largest possible Region.
|
inlineprivate |
Calculate Nyquist frequency index (m_LargestPositiveFrequencyIndex), Min/Max indices from LargestPossibleRegion. Also sets FrequencySpacing and FrequencyOrigin. Called by constructors.
Definition at line 279 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencyOrigin, itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_FrequencySpacing, itk::ImageConstIteratorWithIndex< TImage >::m_Image, itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_LargestPositiveFrequencyIndex, itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_MaxIndex, and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_MinIndex.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::FrequencyFFTLayoutImageRegionConstIteratorWithIndex().
|
inline |
Does nothing. This member only affects HalfHermitianFrequencyIterator. Provided for homogeneous interface between iterators.
Definition at line 266 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
References itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::m_ActualXDimensionIsOdd.
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 303 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::SetActualXDimensionIsOdd().
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 301 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency(), and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 302 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequency(), and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 298 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin(), and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 300 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin(), and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
|
private |
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 (vnl or fftw) to an image. 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].
f = [0, 1, ..., N/2-1, -N/2, ..., -1] * FrequencySpacing if N is even f = [0, 1, ..., (N-1)/2, -(N-1)/2, ..., -1] * FrequencySpacing if N is odd
Where FrequencySpacing = samplingFrequency / N; and samplingFrequency = 1.0 / inputImageSpatialDomainSpacing;
Definition at line 299 of file itkFrequencyFFTLayoutImageRegionConstIteratorWithIndex.h.
Referenced by itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::GetFrequencyBin(), and itk::FrequencyFFTLayoutImageRegionConstIteratorWithIndex< TImage >::Init().
1.8.16
