Example Tutorial¶

import pypiv
import numpy as np
import matplotlib.pyplot as plt
from glob import glob

imgs = ['images/finger1.png', 'images/finger2.png']
#imgs = ['images/test1.png', 'images/test2.png']
frames = [plt.imread(x) for x in imgs]
frame_a, frame_b = frames[0], frames[1]

piv = pypiv.DirectPIV(frame_a, frame_b, window_size=32,
                        search_size=32, distance=16)
piv.correlate_frames()
pypiv.filters.outlier_from_local_median(piv, 2.0)
pypiv.filters.replace_outliers(piv)
pypiv.filters.median_filter(piv)

piv = pypiv.AdaptivePIV(piv, window_size=32,
                              search_size=32, distance=16, ipmethod='cubic')
piv.correlate_frames()
pypiv.filters.outlier_from_local_median(piv, 2.0)
pypiv.filters.replace_outliers(piv)
pypiv.filters.median_filter(piv)

piv = pypiv.AdaptivePIV(piv, window_size=32,
                              search_size=32, distance=8, ipmethod='cubic')#, deformation='central')
piv.correlate_frames()
pypiv.filters.outlier_from_local_median(piv, 2.0)
pypiv.filters.replace_outliers(piv)
pypiv.filters.median_filter(piv)

x, y, u, v = pypiv.postprocess.compute_coordinate_transformations(piv)

fig1 = plt.figure()
ax1 = fig1.add_subplot(111)
ax1.quiver(x,y,u.T,v.T)

fig2 = plt.figure()
ax2 = fig2.add_subplot(111)
cax2 = ax2.imshow(v.T, origin='lower')
fig2.colorbar(cax2)

fig3 = plt.figure()
ax3 = fig3.add_subplot(111)
cax3 = ax3.imshow(u.T, origin='lower')
fig3.colorbar(cax3)
plt.show()