def returnWedgeVolume(self, size, rotation=None):
"""Return the wedge volume in full size and zero in the center
@param size: size of wedge
@type size: C{list}
@param rotation: rotation (3-dim vector if Euler angles)
@type rotation: C{list}
@return: wedge volume
@rtype: Numpy array
"""
assert len(size) == 3, "returnWedgeVolume: size must be 3-dim list"
if self._volume is not None and np.array_equal(self._volume_shape,
size):
pass
else:
self._create_wedge_volume(size)
from pytom.tompy.transform import rotate3d, fourier_reduced2full, fftshift
isodd = self._volume_shape[2] % 2
wedge_vol = fftshift(fourier_reduced2full(self._volume, isodd))
if rotation is not None: # rotate the wedge first
assert len(rotation) == 3
wedge_vol = rotate3d(wedge_vol,
rotation[0],
rotation[1],
rotation[2],
order=1)
return wedge_vol
def apply(self, data, rotation=None):
"""
@param rotation: apply rotation to the wedge first
"""
# if no missing wedge
if self.start_ang == -90 and self.end_ang == 90:
return data
if self._volume is not None and np.array_equal(self._volume_shape,
data.shape):
pass
else:
self._create_wedge_volume(data.shape)
if rotation is not None: # rotate the wedge first
assert len(rotation) == 3
from pytom.tompy.transform import rotate3d, fourier_reduced2full, fourier_full2reduced, fftshift, ifftshift
isodd = self._volume_shape[2] % 2
filter_vol = fftshift(fourier_reduced2full(self._volume, isodd))
filter_vol = rotate3d(filter_vol,
rotation[0],
rotation[1],
rotation[2],
order=1) # linear interp!
filter_vol = fourier_full2reduced(ifftshift(filter_vol))
else:
filter_vol = self._volume
from pytom.tompy.transform import fourier_filter
res = fourier_filter(data, filter_vol, False)
return res
def FLCF(volume, template, mask=None, stdV=None):
'''Fast local correlation function
@param volume: target volume
@param template: template to be searched. It can have smaller size then target volume.
@param mask: template mask. If not given, a default sphere mask will be used.
@param stdV: standard deviation of the target volume under mask, which do not need to be calculated again when the mask is identical.
@return: the local correlation function
'''
if volume.shape[0] < template.shape[0] or volume.shape[1] < template.shape[
1] or volume.shape[2] < template.shape[2]:
raise Exception('Template size is bigger than the target volume!')
# generate the mask
if mask is None:
from tools import create_sphere
mask = create_sphere(template.shape)
else:
if template.shape[0] != mask.shape[0] and template.shape[
1] != mask.shape[1] and template.shape[2] != mask.shape[2]:
raise Exception('Template and mask sizes are not the same!')
# normalize the template under mask
meanT = mean_under_mask(template, mask)
stdT = std_under_mask(template, mask, meanT)
temp = (template - meanT) / stdT
temp = temp * mask
# construct both the template and the mask which has the same size as target volume
from tools import paste_in_center
tempV = temp
if volume.shape[0] != temp.shape[0] or volume.shape[1] != temp.shape[
1] or volume.shape[2] != temp.shape[2]:
tempV = np.zeros(volume.shape)
tempV = paste_in_center(temp, tempV)
maskV = mask
if volume.shape[0] != mask.shape[0] or volume.shape[1] != mask.shape[
1] or volume.shape[2] != mask.shape[2]:
maskV = np.zeros(volume.shape)
maskV = paste_in_center(mask, maskV)
# calculate the mean and std of volume
meanV = mean_vol_under_mask(volume, maskV)
stdV = std_vol_under_mask(volume, maskV, meanV)
from transform import rfft, irfft, fftshift
size = volume.shape
fT = rfft(tempV)
fT = np.conjugate(fT)
result = fftshift(irfft(fT * rfft(volume), size)) / stdV
return result / np.sum(mask)
def toSphericalFunc(self, bw, radius=None, threshold=0.5):
"""Convert the wedge from k-space to a spherical function. \
currently some hard-coded parameters in - bw <=128, r=45 for max bw, default vol 100
@param bw: bandwidth of the spherical function (must be <=128).
@param radius: radius in k-space. For general Wedge, not used for SingleTiltWedge.
@param threshold: threshold, above which the value there would be set to 1.
@return: a spherical function in numpy.array - default 100x100x100 if no self.vol defined
"""
assert (bw <= 128), "toSphericalFunc: bw currently limited to <= 128"
# if no missing wedge
if self.start_ang == -90 and self.end_ang == 90:
self._sf = np.ones((4 * bw**2, ))
return self._sf
r = 45 # this radius and the volume size should be sufficient for sampling b <= 128
if self._volume is None or np.min(self._volume.shape) < 100:
self._create_wedge_volume((100, 100, 100))
if self._bw == bw and self._sf is not None:
return self._sf
else:
self._bw = bw
from pytom.tompy.transform import fourier_reduced2full, fftshift
isodd = self._volume_shape[2] % 2
filter_vol = fftshift(fourier_reduced2full(self._volume, isodd))
# start sampling
from math import pi, sin, cos
res = []
for j in range(2 * bw):
for k in range(2 * bw):
the = pi * (2 * j + 1) / (4 * bw) # (0,pi)
phi = pi * k / bw # [0,2*pi)
# this part actually needs interpolation
x = int(cos(phi) * sin(the) * r + 50)
y = int(sin(phi) * sin(the) * r + 50)
z = int(cos(the) * r + 50)
# if the value is bigger than the threshold, we include it
if filter_vol[x, y, z] > threshold:
res.append(1.0)
else:
res.append(0.0)
# store it so that we don't have to recompute it next time
self._sf = np.array(res)
return self._sf
def set_wedge_volume(self, wedge_vol, half=True, isodd=False):
if half:
self._volume = wedge_vol
# human understandable version with 0-freq in the center
from transform import fourier_reduced2full, fftshift
self._whole_volume = fftshift(
fourier_reduced2full(self._volume, isodd))
else:
self._whole_volume = wedge_vol
from transform import fourier_full2reduced, ifftshift
self._volume = fourier_full2reduced(ifftshift(self._whole_volume))
def mean_vol_under_mask(volume, mask):
"""Calculate the mean volume under the mask (Both should have the same size).
@param volume: input volume.
@param mask: mask.
@return: the calculated mean volume under mask.
"""
p = np.sum(mask)
# do the (circular) convolution
from transform import rfft, irfft, fftshift
size = volume.shape
# somehow this should be conjugated
res = fftshift(irfft(rfft(volume) * np.conjugate(rfft(mask)), size)) / p
return res
def _create_wedge_volume(self, size):
from transform import fftshift, fourier_full2reduced
# if no missing wedge
if self.start_ang == -90 and self.end_ang == 90:
filter_vol = np.ones(size)
self._volume = fourier_full2reduced(filter_vol)
self._volume_shape = size
return
filter_vol = np.ones(size)
x, z = scipy.mgrid[0.:size[0], 0.:size[2]]
x -= size[0] / 2
ind = np.where(x) # find the non-zeros
z -= size[2] / 2
angles = np.zeros(z.shape)
angles[ind] = np.arctan(z[ind] / x[ind]) * 180 / np.pi
angles = np.reshape(angles, (size[0], 1, size[2]))
angles = np.repeat(angles, size[1], axis=1)
filter_vol[angles > -self.start_ang] = 0
filter_vol[angles < -self.end_ang] = 0
filter_vol[size[0] / 2, :, :] = 0
filter_vol[size[0] / 2, :, size[2] / 2] = 1
# create a sphere and multiple it with the wedge
from tools import create_sphere
mask = create_sphere(size)
filter_vol *= mask
# shift and cut in half
filter_vol = fftshift(filter_vol)
self._volume = fourier_full2reduced(filter_vol)
self._volume_shape = size
