def interp(table, coord, input):
'''
Interpolate onto coordinates with given interpolation table
input - [num_channel, nx, ny]
'''
coord_shape = util.get_shape(coord)
ishape = util.get_shape(input)
ndim = coord_shape[-1] # number of image dimensions
bdim = len(ishape) - ndim # number of channel dimensions
kdim = len(coord_shape) - 1 # number of kspace dimensions
img_shape = ishape[-ndim:]
center = [i // 2 for i in img_shape]
with tf.name_scope('get_indices'):
idx = mod(tf.cast(tf.round(coord), 'int64') + center, img_shape)
input = tf.transpose(input,
perm=list(range(bdim, bdim + ndim)) +
list(range(bdim)))
output = tf.gather_nd(input, idx)
output = tf.transpose(output,
perm=list(range(kdim, kdim + bdim)) +
list(range(kdim)))
with tf.name_scope('get_weights'):
diff = abs(tf.round(coord) - coord) * 2.0
weight = tf.reduce_prod(linear_interp(table, diff), axis=-1)
output *= weight
return output
def check_codomain(self, output):
if output.dtype.base_dtype != self.dtype:
raise ValueError('output dtype mismatch, for {}, got {}'
.format(self, output.dtype))
if util.get_shape(output) != self.oshape:
raise ValueError('output shape mismatch, for {}, got {}'
.format(self, util.get_shape(output)))
def check_domain(self, input):
if input.dtype.base_dtype != self.dtype:
raise ValueError('input data type mismatch, for {}, got {}'
.format(self, input.dtype))
if util.get_shape(input) != self.ishape:
raise ValueError('input shape mismatch, for {}, got {}'
.format(self, util.get_shape(input)))
def __init__(self, ishape, table, coord,
shift=None, dtype=tf.complex64):
coord = tf.convert_to_tensor(coord)
table = tf.convert_to_tensor(table)
ndim = util.get_shape(coord)[-1]
ishape = list(ishape)
self.table = table
self.coord = coord
self.shift = shift
batch = ishape[:-ndim]
self.img_shape = ishape[-ndim:]
oshape = batch + util.get_shape(coord)[:-1]
super().__init__(oshape, ishape, dtype)
def __init__(self, oshape, ishape, mat, dtype=tf.complex64):
self.mat = tf.convert_to_tensor(mat)
mshape = util.get_shape(self.mat)
max_ndim = max(len(oshape), len(ishape), len(mshape))
oshape_full = [1] * (max_ndim - len(oshape)) + oshape
ishape_full = [1] * (max_ndim - len(ishape)) + ishape
mshape_full = [1] * (max_ndim - len(mshape)) + mshape
# Check dimension valid.
for i, o, m in zip(ishape_full[:-2], oshape_full[:-2], mshape_full[:-2]):
if not ((i == m and o == m) or
(i == m and o == 1) or
(i == 1 and o == m) or
(i == 1 and o == 1) or
(i == o and m == 1)):
raise ValueError('Invalid dimensions: {}, {}, {}'.
format(oshape, ishape, mat.shape))
self.osum_axes = [i for i in range(max_ndim)
if oshape_full[i] == 1]
self.isum_axes = [i for i in range(max_ndim)
if ishape_full[i] == 1]
ndim = len(oshape)
self.perm = list(range(ndim - 2)) + [ndim - 1, ndim - 2]
super().__init__(oshape, ishape, dtype)
def interpH(oshape, table, coord, input):
coord_shape = util.get_shape(coord)
ndim = coord_shape[-1]
bdim = len(oshape) - ndim
kdim = len(coord_shape) - 1
img_shape = oshape[-ndim:]
center = [i // 2 for i in img_shape]
idx = mod(tf.cast(tf.round(coord), 'int64') + center, img_shape)
diff = abs(tf.round(coord) - coord) * 2.0
weight = tf.reduce_prod(linear_interp(table, diff), axis=-1)
input *= weight
input = tf.transpose(input,
perm=list(range(bdim, bdim + kdim)) +
list(range(bdim)))
output = tf.scatter_nd(idx, input, oshape[-ndim:] + oshape[:-ndim])
output = tf.transpose(output,
perm=list(range(ndim, ndim + bdim)) +
list(range(ndim)))
return output
def getNumInstances(self, infile, time_context=100, step=25):
"""
For a single .data file computes the number of examples of size \"time_context\" that can be created
"""
shape = util.get_shape(os.path.join(infile.replace('.data', '.shape')))
length_file = float(shape[0])
return np.maximum(
1, int(np.ceil((length_file - time_context) / self.step)))
def __init__(self, oshape, ishape, mult, dtype=tf.complex64):
self.mult = tf.convert_to_tensor(mult)
if self.mult.dtype.base_dtype != dtype:
self.mult = tf.cast(self.mult, dtype)
super().__init__(oshape, ishape, dtype)
mshape = util.get_shape(self.mult)
max_ndim = max(max(len(oshape), len(ishape)), len(mshape))
oshape = [1] * (max_ndim - len(oshape)) + list(oshape)
ishape = [1] * (max_ndim - len(ishape)) + list(ishape)
mshape = [1] * (max_ndim - len(mshape)) + list(mshape)
self.osum_axis = [i for i in range(max_ndim) if (oshape[i] == 1 and
(ishape[i] > 1 or mshape[i] > 1))]
self.isum_axis = [i for i in range(max_ndim) if (ishape[i] == 1 and
(oshape[i] > 1 or mshape[i] > 1))]
def right_sweep(mps, data, context):
# do all but the rightmost site
for loc in range(len(mps) - 1):
effective_data, context = prepare_effective_data(mps, data, loc, context)
local_tensor = fresh_local_tensor(effective_data)
p, q = factor_local_tensor(local_tensor, shape=get_shape(mps, loc), direction='R')
mps[loc] = p
mps[loc + 1] = np.tensordot(q, mps[loc + 1], axes=[-1, 0])
if context.get('combs_l'): # not there on the first sweep
context['combs_l'][loc] = None
context['combs_r'][loc] = None
context['step'] += 1
return mps, context
def left_sweep(mps, data, context):
last_index = len(mps) - 1
for offset in range(len(mps) - 1):
loc = last_index - offset
effective_data, context = prepare_effective_data(mps, data, loc, context)
local_tensor = fresh_local_tensor(effective_data)
p, q = factor_local_tensor(local_tensor, shape=get_shape(mps, loc), direction='L')
mps[loc - 1] = np.matmul(mps[loc - 1], p)
mps[loc] = q
context['combs_l'][loc] = None
context['combs_r'][loc] = None
context['step'] += 1
return mps, context
def NUFFT(ishape, coord, n=128, shifts=None, dtype=tf.complex64):
'''
ishape : [batch, nz, ny, nx] or [batch, ny, nx]
coord : tensor of shape [..., ndim]
width = 2.0
oversamp = 2
'''
coord = tf.convert_to_tensor(coord)
ishape = list(ishape)
ndim = util.get_shape(coord)[-1]
beta = np.pi * (1.5 ** 2 - 0.8) ** 0.5
assert len(ishape) == ndim + 1
# Apodization
D = KaiserApodize(ishape, beta, ndim, dtype=dtype)
# Get interpolation table
kaiser_table = tf.constant(np.concatenate([kb(np.arange(n) / n, 2.0, beta), [0]]),
dtype='float32',
name='kaiser_table')
# FFT
F = FFT(ishape, ndim=ndim, dtype=dtype)
As = []
if shifts is None:
shifts = list(product([0, 0.5], repeat=ndim))
for shift in shifts:
freq_shift = [s / i for s, i in zip(shift, ishape[-ndim:])]
L = LinearPhase(ishape, freq_shift, dtype=dtype)
I = Interp(ishape, kaiser_table, coord, shift=shift, dtype=dtype)
As.append(I * F * L * D)
A = AddN(As)
A.add_name_scope('NUFFT')
return A
def __init__(self, ishape, filt, mode='full', dtype=tf.complex64):
self.filt = tf.convert_to_tensor(filt)
self.mode = mode
self.ndim = len(ishape) - 2
fshape = util.get_shape(self.filt)
if mode == 'full':
oshape = ([ishape[0]] +
[i1 + i2 - 1 for i1, i2 in zip(ishape[1:-1], fshape[:-2])]
+ [fshape[-1]])
self.mode_adj = 'valid'
else:
oshape = ([ishape[0]] +
[i1 - i2 + 1 for i1, i2 in zip(ishape[1:-1], fshape[:-2])]
+ [fshape[-1]])
self.zshape = ([ishape[0]] +
[i1 + i2 - 1 for i1, i2 in zip(ishape[1:-1], fshape[:-2])]
+ [fshape[-1]])
self.mode_adj = 'full'
self.perm = list(range(self.ndim)) + [self.ndim + 1, self.ndim]
self.filt_adj = tf.conj(tf.transpose(self.filt, self.perm))
super().__init__(oshape, ishape, dtype)
def getFeatureSize(self, infile):
"""
For a single .data file return the number of feature, e.g. number of spectrogram bins
"""
shape = util.get_shape(os.path.join(infile.replace('.data', '.shape')))
return shape[1]