In [1]:
!pip install imageio numpy matplotlib
!pip install -e .
Requirement already satisfied: imageio in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (2.8.0)
Requirement already satisfied: numpy in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (1.18.1)
Requirement already satisfied: matplotlib in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (3.2.1)
Requirement already satisfied: pillow in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from imageio) (7.1.2)
Requirement already satisfied: pyparsing!=2.0.4,!=2.1.2,!=2.1.6,>=2.0.1 in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from matplotlib) (2.4.7)
Requirement already satisfied: kiwisolver>=1.0.1 in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from matplotlib) (1.2.0)
Requirement already satisfied: python-dateutil>=2.1 in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from matplotlib) (2.8.1)
Requirement already satisfied: cycler>=0.10 in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from matplotlib) (0.10.0)
Requirement already satisfied: six>=1.5 in /Users/alexliberzon/miniconda3/envs/openpiv_lite_jupyter/lib/python3.7/site-packages (from python-dateutil>=2.1->matplotlib) (1.15.0)
Obtaining file:///Users/alexliberzon/Documents/repos/openpiv_python_lite
Installing collected packages: openpiv-python-lite
Attempting uninstall: openpiv-python-lite
Found existing installation: openpiv-python-lite 0.1
Uninstalling openpiv-python-lite-0.1:
Successfully uninstalled openpiv-python-lite-0.1
Running setup.py develop for openpiv-python-lite
Successfully installed openpiv-python-lite
In [2]:
from openpiv_python_lite import extended_search_area_piv as piv, get_coordinates, random_noise
In [3]:
import numpy as np
frame_a = np.zeros((32, 32))
frame_a = random_noise(frame_a)
frame_b = np.roll(np.roll(frame_a, 3, axis=1), 2, axis=0)
threshold = 0.1
def test_piv_32():
""" test of the simplest PIV run 32 x 32 """
u, v = piv(frame_a, frame_b, window_size=32)
assert(np.abs(u-3) < threshold)
assert(np.abs(v+2) < threshold)
def test_piv_16_32():
""" test of the search area larger than the window """
u, v = piv(frame_a, frame_b, window_size=16, search_area_size=32)
assert(np.abs(u[0,0]-3) < threshold)
assert(np.abs(v[0,0]+2) < threshold)
In [4]:
test_piv_32()
In [5]:
test_piv_16_32()
In [6]:
import imageio
def test_piv():
"""
Simplest PIV run on the pair of images using default settings
piv(im1,im2) will create a tmp.vec file with the vector filed in pix/dt (dt=1) from
two images, im1,im2 provided as full path filenames (TIF is preferable, whatever imageio can read)
"""
# if im1 is None and im2 is None:
im1 = ('./test/img/frame_a.tif')
im2 = ('./test/img/frame_b.tif')
frame_a = imageio.imread(im1)
frame_b = imageio.imread(im2)
frame_a[0:32, 512-32:] = 255
print(frame_a[0,0])
u, v = piv(frame_a,frame_b,
window_size=32,overlap=16)
x, y = get_coordinates(image_size = frame_a.shape,
window_size=32, overlap=16)
print(x[0], y[0], u[0], v[0])
return x, y, u, v
In [7]:
x,y,u,v = test_piv()
0
[ 16. 32. 48. 64. 80. 96. 112. 128. 144. 160. 176. 192. 208. 224.
240. 256. 272. 288. 304. 320. 336. 352. 368. 384. 400. 416. 432. 448.
464. 480. 496.] [16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16.
16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16. 16.] [ 0.95938837 0.98346617 1.04784319 1.05886846 1.20761461 1.26742268
1.34640937 1.42034135 1.39168986 1.40575022 1.36677195 1.40086036
1.3123752 1.24080693 1.30784351 1.1512783 1.16767496 1.01316333
0.94193456 0.90701145 0.78900817 0.78919477 0.60782558 0.67340273
0.59532751 0.50765493 0.4711314 0.47280763 0.3971003 -4.14878738
nan] [ 7.98213358e-01 7.63942158e-01 7.38243280e-01 6.83750739e-01
6.35287937e-01 5.40945934e-01 4.83806352e-01 4.30068140e-01
2.87314701e-01 1.70037066e-01 6.34608020e-02 -3.12106990e-03
-4.91035959e-02 -2.30341249e-01 -2.85272009e-01 -3.86972508e-01
-4.49199516e-01 -5.06701844e-01 -5.31754472e-01 -5.82787049e-01
-5.91071528e-01 -5.77511702e-01 -6.52894696e-01 -6.09258543e-01
-5.51941830e-01 -6.86901207e-01 -6.55891684e-01 -6.25888334e-01
-6.58582637e-01 -1.62875551e+01 nan]
/Users/alexliberzon/Documents/repos/openpiv_python_lite/openpiv_python_lite/pyprocess.py:265: RuntimeWarning: divide by zero encountered in log subp_peak_position = (peak1_i + ((log(cl) - log(cr)) / (2 * log(cl) - 4 * log(c) + 2 * log(cr))), /Users/alexliberzon/Documents/repos/openpiv_python_lite/openpiv_python_lite/pyprocess.py:265: RuntimeWarning: invalid value encountered in double_scalars subp_peak_position = (peak1_i + ((log(cl) - log(cr)) / (2 * log(cl) - 4 * log(c) + 2 * log(cr))), /Users/alexliberzon/Documents/repos/openpiv_python_lite/openpiv_python_lite/pyprocess.py:266: RuntimeWarning: divide by zero encountered in log peak1_j + ((log(cd) - log(cu)) / (2 * log(cd) - 4 * log(c) + 2 * log(cu)))) /Users/alexliberzon/Documents/repos/openpiv_python_lite/openpiv_python_lite/pyprocess.py:266: RuntimeWarning: invalid value encountered in double_scalars peak1_j + ((log(cd) - log(cu)) / (2 * log(cd) - 4 * log(c) + 2 * log(cu))))
In [8]:
import pylab
In [9]:
pylab.quiver(x,y,u,-v)
Out[9]:
<matplotlib.quiver.Quiver at 0x7fcf60f734d0>
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