#!/usr/bin/env python # coding: utf-8 # # OpenPIV Tutorial # # # In this tutorial we read the pair of images using `imread`, compare them visually # and process using OpenPIV. Here the import is using directly the basic functions and methods # In[1]: from openpiv import tools, process, validation, filters, scaling import numpy as np import matplotlib.pyplot as plt get_ipython().run_line_magic('matplotlib', 'inline') import imageio # In[2]: frame_a = tools.imread( '../test1/exp1_001_a.bmp' ) frame_b = tools.imread( '../test1/exp1_001_b.bmp' ) # In[3]: fig,ax = plt.subplots(1,2,figsize=(12,10)) ax[0].imshow(frame_a,cmap=plt.cm.gray) ax[1].imshow(frame_b,cmap=plt.cm.gray) # In[4]: winsize = 24 # pixels searchsize = 64 # pixels, search in image B overlap = 12 # pixels dt = 0.02 # sec u0, v0, sig2noise = process.extended_search_area_piv( frame_a.astype(np.int32), frame_b.astype(np.int32), window_size=winsize, overlap=overlap, dt=dt, search_area_size=searchsize, sig2noise_method='peak2peak' ) # In[5]: x, y = process.get_coordinates( image_size=frame_a.shape, window_size=winsize, overlap=overlap ) # In[6]: u1, v1, mask = validation.sig2noise_val( u0, v0, sig2noise, threshold = 1.3 ) # In[7]: u2, v2 = filters.replace_outliers( u1, v1, method='localmean', max_iter=10, kernel_size=2) # In[8]: x, y, u3, v3 = scaling.uniform(x, y, u2, v2, scaling_factor = 96.52 ) # In[9]: tools.save(x, y, u3, v3, mask, 'exp1_001.txt' ) # In[10]: tools.display_vector_field('exp1_001.txt', scale=50, width=0.0025) # In[17]: # If you need a larger view: fig, ax = plt.subplots(figsize=(12,12)) tools.display_vector_field('exp1_001.txt', ax=ax, scaling_factor=96.52, scale=50, width=0.0025, on_img=True, image_name='../test1/exp1_001_a.bmp'); # In[ ]: