distance_transform_lin

A variant of the standard distance transform where the distances are computed along a give axis rather than radially.

import numpy as np
import porespy as ps
import scipy.ndimage as spim
import matplotlib.pyplot as plt
ps.visualization.set_mpl_style()

/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/openpnm/algorithms/_invasion_percolation.py:358: NumbaDeprecationWarning: The 'nopython' keyword argument was not supplied to the 'numba.jit' decorator. The implicit default value for this argument is currently False, but it will be changed to True in Numba 0.59.0. See https://numba.readthedocs.io/en/stable/reference/deprecation.html#deprecation-of-object-mode-fall-back-behaviour-when-using-jit for details.
  def _find_trapped_pores(inv_seq, indices, indptr, outlets):  # pragma: no cover

The arguments and their defaults are:

import inspect
inspect.signature(ps.filters.distance_transform_lin)

<Signature (im, axis=0, mode='both')>

axis

The axis along which the distances should be computed

fig, ax = plt.subplots(1, 2, figsize=[12, 6])

im = ps.generators.blobs(shape=[500, 500], porosity=0.7)

axis = 0
dt = ps.filters.distance_transform_lin(im, axis=axis)

ax[0].imshow(dt/im)
ax[0].axis(False)
ax[0].set_title(f'axis = {axis}')

axis = 1
dt = ps.filters.distance_transform_lin(im, axis=axis)

ax[1].imshow(dt/im)
ax[1].axis(False)
ax[1].set_title(f'axis = {axis}');

mode

Whether the distances are comptuted from the start to end, end to start, or both.

fig, ax = plt.subplots(1, 3, figsize=[15, 5])

im = ps.generators.blobs(shape=[500, 500], porosity=0.7)

mode = 'forward'
dt = ps.filters.distance_transform_lin(im, mode=mode)

ax[0].imshow(dt/im)
ax[0].axis(False)
ax[0].set_title(f'mode = {mode}')

mode = 'reverse'
dt = ps.filters.distance_transform_lin(im, mode=mode)

ax[1].imshow(dt/im)
ax[1].axis(False)
ax[1].set_title(f'mode = {mode}')

mode = 'both'
dt = ps.filters.distance_transform_lin(im, mode=mode)

ax[2].imshow(dt/im)
ax[2].axis(False)
ax[2].set_title(f'mode = {mode}');