Source code for cil.processors.Binner

#  Copyright 2021 United Kingdom Research and Innovation
#  Copyright 2021 The University of Manchester
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
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#      http://www.apache.org/licenses/LICENSE-2.0
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# Authors:
# CIL Developers, listed at: https://github.com/TomographicImaging/CIL/blob/master/NOTICE.txt

from cil.processors import Slicer
import numpy as np

try:
    from cil.processors.cilacc_binner import Binner_IPP
    has_ipp = True
except:
    has_ipp = False

# Note to developers: Binner and Slicer share a lot of common code
# so Binner has been implemented as a child of Slicer. This makes use
# of commonality and redefines only the methods that differ. These methods
# dictate the style of slicer
[docs]class Binner(Slicer): """This creates a Binner processor. The processor will crop the data, and then average together n input pixels along a dimension from the starting index. The output will be a data container with the data, and geometry updated to reflect the operation. Parameters ---------- roi : dict The region-of-interest to bin {'axis_name1':(start,stop,step), 'axis_name2':(start,stop,step)} The `key` being the axis name to apply the processor to, the `value` holding a tuple containing the ROI description Start: Starting index of input data. Must be an integer, or `None` defaults to index 0. Stop: Stopping index of input data. Must be an integer, or `None` defaults to index N. Step: Number of pixels to average together. Must be an integer or `None` defaults to 1. accelerated : boolean, default=True Uses the CIL accelerated backend if `True`, numpy if `False`. Example ------- >>> from cil.processors import Binner >>> roi = {'horizontal':(10,-10,2),'vertical':(10,-10,2)} >>> processor = Binner(roi) >>> processor.set_input(data) >>> data_binned = processor.get_output() Example ------- >>> from cil.processors import Binner >>> roi = {'horizontal':(None,None,2),'vertical':(None,None,2)} >>> processor = Binner(roi) >>> processor.set_input(data.geometry) >>> geometry_binned = processor.get_output() Note ---- The indices provided are start inclusive, stop exclusive. All elements along a dimension will be included if the axis does not appear in the roi dictionary, or if passed as {'axis_name',-1} If only one number is provided, then it is interpreted as Stop. i.e. {'axis_name1':(stop)} If two numbers are provided, then they are interpreted as Start and Stop i.e. {'axis_name1':(start, stop)} Negative indexing can be used to specify the index. i.e. {'axis_name1':(10, -10)} will crop the dimension symmetrically If Stop - Start is not multiple of Step, then the resulted dimension will have (Stop - Start) // Step elements, i.e. (Stop - Start) % Step elements will be ignored """ def __init__(self, roi = None, accelerated=True): if accelerated and not has_ipp: raise RuntimeError("Cannot run accelerated Binner without the IPP libraries.") super(Binner,self).__init__(roi = roi) self._accelerated = True def _configure(self): """ Once the ROI has been parsed this configures the input specifically for use with Binner """ #as binning we only include bins that are inside boundaries self._shape_out = [int((x.stop - x.start)//x.step) for x in self._roi_ordered] self._pixel_indices = [] # fix roi_ordered for binner based on shape out for i in range(4): start = self._roi_ordered[i].start stop = self._roi_ordered[i].start + self._shape_out[i] * self._roi_ordered[i].step self._roi_ordered[i] = range( start, stop, self._roi_ordered[i].step ) self._pixel_indices.append((start, stop-1)) def _get_slice_position(self, roi): """ Return the vertical position to extract a single slice for binned geometry """ return roi.start + roi.step/2 def _get_angles(self, roi): """ Returns the binned angles according to the roi """ n_elements = len(roi) shape = (n_elements, roi.step) return self._geometry.angles[roi.start:roi.start+n_elements*roi.step].reshape(shape).mean(1) def _bin_array_numpy(self, array_in, array_binned): """ Bins the array using numpy. This method is slower and less memory efficient than self._bin_array_acc """ shape_object = [] slice_object = [] for i in range(4): # reshape the data to add each 'bin' dimensions shape_object.append(self._shape_out[i]) shape_object.append(self._roi_ordered[i].step) shape_object = tuple(shape_object) slice_object = tuple([slice(x.start, x.stop) for x in self._roi_ordered]) data_resized = array_in.reshape(self._shape_in)[slice_object].reshape(shape_object) mean_order = (-1, 1, 2, 3) for i in range(4): data_resized = data_resized.mean(mean_order[i]) np.copyto(array_binned, data_resized) def _bin_array_acc(self, array_in, array_binned): """ Bins the array using the accelerated CIL backend """ indices_start = [x.start for x in self._roi_ordered] bins = [x.step for x in self._roi_ordered] binner_ipp = Binner_IPP(self._shape_in, self._shape_out, indices_start, bins) res = binner_ipp.bin(array_in, array_binned) if res != 0: raise RuntimeError("Call failed") def _process_data(self, dc_in, dc_out): """ Bin the data array """ if self._accelerated: self._bin_array_acc(dc_in.array, dc_out.array) else: self._bin_array_numpy(dc_in.array, dc_out.array)