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cdtools/CDTools/models/incoherent_ptycho.py
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from __future__ import division, print_function, absolute_import
import torch as t
from CDTools.models import CDIModel
from CDTools import tools
from copy import copy
import numpy as np
class IncoherentPtycho(CDIModel):
def __init__(self, wavelength, detector_geometry,
probe_basis, detector_slice,
probe_guess, obj_guess, min_translation = t.Tensor([0,0]),
translation_offsets=None,
background = None, mask=None, weights = None):
super(IncoherentPtycho,self).__init__()
self.wavelength = t.Tensor([wavelength])
self.detector_geometry = copy(detector_geometry)
det_geo = self.detector_geometry
if hasattr(det_geo, 'distance'):
det_geo['distance'] = t.Tensor(det_geo['distance'])
if hasattr(det_geo, 'basis'):
det_geo['basis'] = t.Tensor(det_geo['basis'])
if hasattr(det_geo, 'corner'):
det_geo['corner'] = t.Tensor(det_geo['corner'])
self.min_translation = t.Tensor(min_translation)
self.probe_basis = t.Tensor(probe_basis)
self.detector_slice = detector_slice
if mask is None:
self.mask = mask
else:
self.mask = t.ByteTensor(mask)
# We rescale the probe here so it learns at the same rate as the
# object
probe_norm = t.max(tools.cmath.cabs(probe_guess[0].to(t.float32)))
self.probe = t.nn.Parameter(probe_guess.to(t.float32)/probe_norm)
self.probe_norm = float(probe_norm.numpy())
self.obj = t.nn.Parameter(obj_guess.to(t.float32))
if background is None:
background = 1e-6 * t.ones(self.probe[(np.s_[0],)+self.detector_slice].shape[:-1])
self.background = t.nn.Parameter(t.Tensor(background).to(t.float32))
if weights is None:
self.weights = None
else:
self.weights = t.nn.Parameter(t.Tensor(weights).to(t.float32))
if translation_offsets is None:
self.translation_offsets = None
else:
self.translation_offsets = t.nn.Parameter(t.Tensor(translation_offsets).to(t.float32))
@classmethod
def from_dataset(cls, dataset, probe_size=None, randomize_ang=0, padding=0):
wavelength = dataset.wavelength
det_basis = dataset.detector_geometry['basis']
det_shape = dataset[0][1].shape
distance = dataset.detector_geometry['distance']
# always do this on the cpu
get_as_args = dataset.get_as_args
dataset.get_as(device='cpu')
(indices, translations), patterns = dataset[:]
dataset.get_as(*get_as_args[0],**get_as_args[1])
# Set to none to avoid issues with things outside the detector
center = tools.image_processing.centroid(t.sum(patterns,dim=0))
# Then, generate the probe geometry from the dataset
ewg = tools.initializers.exit_wave_geometry
probe_basis, probe_shape, det_slice = ewg(det_basis,
det_shape,
wavelength,
distance,
center=center,
padding=padding,
opt_for_fft=False)
# Next generate the object geometry from the probe geometry and
# the translations
pix_translations = tools.interactions.translations_to_pixel(probe_basis, translations)
obj_size, min_translation = tools.initializers.calc_object_setup(probe_shape, pix_translations, padding=20)
# Finally, initialize the probe and object using this information
if probe_size is None:
probe = tools.initializers.SHARP_style_probe(dataset, probe_shape, det_slice)
else:
probe = tools.initializers.gaussian_probe(dataset, probe_basis, probe_shape, probe_size)
translation_offsets = 0 * (t.rand((len(dataset),2)) - 0.5)
# For incoherent probe mixing
probe = t.stack((probe,0.05*t.rand(probe.shape).to(probe.dtype)))
obj = tools.cmath.expi(randomize_ang * (t.rand(obj_size)-0.5))
det_geo = dataset.detector_geometry
weights = t.ones(len(dataset))
if hasattr(dataset, 'mask') and dataset.mask is not None:
mask = dataset.mask.to(t.uint8)
else:
mask = None
return cls(wavelength, det_geo, probe_basis, det_slice, probe, obj, min_translation=min_translation, translation_offsets=translation_offsets, weights=weights, mask=mask)
def interaction(self, index, translations):
pix_trans = tools.interactions.translations_to_pixel(self.probe_basis,
translations)
# The 10x term is to condition the translation offsets
pix_trans -= self.min_translation
pix_trans = pix_trans + self.translation_offsets[index]
all_exit_waves = []
for i in range(self.probe.shape[0]):
exit_waves = self.probe_norm * tools.interactions.ptycho_2D_sinc(self.probe[i],
self.obj,
pix_trans,
shift_probe=True)
if exit_waves.dim() == 4:
exit_waves = self.weights[index][:,None,None,None] * exit_waves
else:
exit_waves = self.weights[index] * exit_waves
all_exit_waves.append(exit_waves)
return t.stack(all_exit_waves)
def forward_propagator(self, wavefields):
return tools.propagators.far_field(wavefields)
def backward_propagator(self, wavefields):
return tools.propagators.inverse_far_field(wavefields)
def measurement(self, wavefields):
return tools.measurements.quadratic_background(wavefields,
self.background,
detector_slice=self.detector_slice,
measurement=tools.measurements.incoherent_sum)
def loss(self, sim_data, real_data, mask=None):
return tools.losses.amplitude_mse(real_data, sim_data, mask=mask)
def to(self, *args, **kwargs):
super(IncoherentPtycho, self).to(*args, **kwargs)
self.wavelength = self.wavelength.to(*args,**kwargs)
# move the detector geometry too
det_geo = self.detector_geometry
if hasattr(det_geo, 'distance'):
det_geo['distance'] = det_geo['distance'].to(*args,**kwargs)
if hasattr(det_geo, 'basis'):
det_geo['basis'] = det_geo['basis'].to(*args,**kwargs)
if hasattr(det_geo, 'corner'):
det_geo['corner'] = det_geo['corner'].to(*args,**kwargs)
if self.mask is not None:
self.mask = self.mask.to(*args, **kwargs)
self.min_translation = self.min_translation.to(*args,**kwargs)
self.probe_basis = self.probe_basis.to(*args,**kwargs)
def sim_to_dataset(self, args_list):
pass