def fft(array, interpolation=1.0, window='tukey', *kwargs):
""" A n-dimensional Forward Discrete Fourier transform with some extra bells and whistles
added on top of the standard Numpy method.
:param array: the image to be transformed
:type array: np.ndarray
:param interpolation: Add "interpolation" to the FFT by zero-padding prior to transform.
This is expressed as a multiple of the image size.
:type interpolation: float
:param window: a window function to apply. 'tukey' or 'hamming'
:type window: str or None
:return: the complex Fourier transform of the input array
"""
# Apply a Window if requested
if window is None:
pass
elif window == 'tukey':
array = windowing.apply_tukey_window(array, *kwargs)
elif window == 'hamming':
array = windowing.apply_hamming_window(array)
# Add extra padding
if interpolation > 1.0:
new_shape = tuple(int(interpolation * i) for i in array.shape)
array = ndarray.expand_to_shape(array, new_shape)
# Transform forward
array = np.fft.fftshift(np.fft.fftn(array))
return array
def __get_fourier_psfs(self):
"""
Pre-calculates the PSFs during image fusion process.
"""
psf = self.psf[:]
if self.imdims == 3:
adj_psf = psf[::-1, ::-1, ::-1]
else:
adj_psf = psf[::-1, ::-1]
padded_block_size = tuple(self.block_size + 2*self.options.block_pad)
psf_fft = ops_array.expand_to_shape(psf, padded_block_size).astype(np.complex64)
adj_psf_fft = ops_array.expand_to_shape(adj_psf, padded_block_size).astype(np.complex64)
psf_fft = np.fft.fftshift(psf_fft)
adj_psf_fft = np.fft.fftshift(adj_psf_fft)
self.psf_fft = np.fft.fftn(psf_fft)
self.adj_psf_fft = np.fft.fftn(adj_psf_fft)
def __get_fourier_psfs(self):
"""
Pre-calculates the PSFs during image fusion process.
"""
print("Pre-calculating PSFs")
padded_block_size = tuple(self.block_size + 2 * self.options.block_pad)
memmap_shape = (self.n_views, ) + padded_block_size
if self.options.disable_fft_psf_memmap:
self.psfs_fft = numpy.zeros(memmap_shape, dtype=numpy.complex64)
self.adj_psfs_fft = numpy.zeros(memmap_shape,
dtype=numpy.complex64)
else:
psfs_fft_f = os.path.join(self.memmap_directory, "psf_fft_f.dat")
self.psfs_fft = numpy.memmap(psfs_fft_f,
dtype='complex64',
mode='w+',
shape=memmap_shape)
adj_psfs_fft_f = os.path.join(self.memmap_directory,
"adj_psf_fft_f.dat")
self.adj_psfs_fft = numpy.memmap(adj_psfs_fft_f,
dtype='complex64',
mode='w+',
shape=memmap_shape)
for idx in range(self.n_views):
self.psfs_fft[idx] = ops_array.expand_to_shape(
self.psfs[idx], padded_block_size).astype(numpy.complex64)
self.adj_psfs_fft[idx] = ops_array.expand_to_shape(
self.adj_psfs[idx], padded_block_size).astype(numpy.complex64)
self.psfs_fft[idx] = numpy.fft.fftshift(self.psfs_fft[idx])
self.adj_psfs_fft[idx] = numpy.fft.fftshift(self.adj_psfs_fft[idx])
self.psfs_fft[idx] = cp.asnumpy(
fftpack.fftn(cp.asarray(self.psfs_fft[idx]),
plan=self._fft_plan))
self.adj_psfs_fft[idx] = cp.asnumpy(
fftpack.fftn(cp.asarray(self.adj_psfs_fft[idx]),
plan=self._fft_plan))
def __get_fourier_psfs(self):
"""
Pre-calculates the PSFs during image fusion process.
"""
print("Pre-calculating PSFs")
padded_block_size = tuple(self.block_size + 2 * self.options.block_pad)
memmap_shape = numpy.insert(numpy.array(padded_block_size), 0,
len(self.views))
if self.options.disable_fft_psf_memmap:
self.psfs_fft = numpy.zeros(tuple(memmap_shape),
dtype=numpy.complex64)
self.adj_psfs_fft = numpy.zeros(tuple(memmap_shape),
dtype=numpy.complex64)
else:
psfs_fft_f = os.path.join(self.memmap_directory, 'psf_fft_f.dat')
self.psfs_fft = numpy.memmap(psfs_fft_f,
dtype='complex64',
mode='w+',
shape=tuple(memmap_shape))
adj_psfs_fft_f = os.path.join(self.memmap_directory,
'adj_psf_fft_f.dat')
self.adj_psfs_fft = numpy.memmap(adj_psfs_fft_f,
dtype='complex64',
mode='w+',
shape=tuple(memmap_shape))
for idx in range(self.n_views):
self.psfs_fft[idx] = ops_array.expand_to_shape(
self.psfs[idx], padded_block_size).astype(numpy.complex64)
self.adj_psfs_fft[idx] = ops_array.expand_to_shape(
self.adj_psfs[idx], padded_block_size).astype(numpy.complex64)
self.psfs_fft[idx] = numpy.fft.fftshift(self.psfs_fft[idx])
self.adj_psfs_fft[idx] = numpy.fft.fftshift(self.adj_psfs_fft[idx])
fft_inplace(self.psfs_fft[idx])
fft_inplace(self.adj_psfs_fft[idx])
def ifft(array_f, interpolation=1.0):
""" A n-dimensional Inverse Discrete Fourier transform with some extra bells and whistles
added on top of the standard Numpy method. Assumes a FFT shifted Fourier domain image.
:param array_f: the image to be transformed
:type array_f: np.ndarray
:param interpolation: add interpolation, by defining a value > 1.0. Corresponds to
enlargement of the result image.
:type interpolation: float
:return: returns the iFFTd array
"""
# Add padding
if interpolation > 1.0:
new_shape = tuple(int(interpolation * i) for i in array_f.shape)
array_f = ndarray.expand_to_shape(array_f, new_shape)
# Transform back
iarray_f = np.fft.ifftn(np.fft.fftshift(array_f))
return iarray_f
def __init__(self, shape, d_bin, d_angle):
"""
:param shape: Shape of the data
:param d_bin: The radius increment size (pixels)
:param d_angle: The angle increment size (degrees)
"""
assert len(shape) == 3, "This iterator assumes a 3D shape"
FourierShellIterator.__init__(self, shape, d_bin)
plane = nputils.expand_to_shape(np.ones((1, shape[1], shape[2])),
shape)
self.plane = itkutils.convert_from_numpy(plane, (1, 1, 1))
self.rotated_plane = plane > 0
self.rotation_start = 0
self.rotation_stop = 360 / d_angle - 1
self.current_rotation = self.rotation_start
self.angles = np.arange(0, 360, d_angle, dtype=int)
