alexlib/openpiv-python — Issue #26: OpenPIV not working for those images
Author: romainreuillon
Created: 2011-12-18 14:41:23+00:00
State: open

Hi guys,

thank you for OpenPIV it is a very useful piece of software!

I would like to process those images:
https://public.iscpif.fr/~reuillon/m1.jpg
https://public.iscpif.fr/~reuillon/m2.jpg

For that purpose I use this script (from the tutorial 1):
import openpiv.tools
import openpiv.process
import openpiv.scaling

frame_a = openpiv.tools.imread( 'm1.jpg' )
frame_b = openpiv.tools.imread( 'm2.jpg' )

u, v, sig2noise = openpiv.process.extended_search_area_piv( frame_a, frame_b, window_size=24, overlap=12, dt=0.02, search_area_size=64, sig2noise_method='peak2peak' )

x, y = openpiv.process.get_coordinates( image_size=frame_a.shape, window_size=24, overlap=12 )

u, v, mask = openpiv.validation.sig2noise_val( u, v, sig2noise, threshold = 1.3 )

u, v = openpiv.filters.replace_outliers( u, v, method='localmean', max_iter=10, kernel_size=2)

x, y, u, v = openpiv.scaling.uniform(x, y, u, v, scaling_factor = 96.52 )

openpiv.tools.save(x, y, u, v, mask, 'exp1_001.txt' )

openpiv.tools.display_vector_field('exp1_001.txt', scale=100, width=0.0025)

However I got this error message:
Traceback (most recent call last):
File "tutorial-part1.py", line 8, in
u, v, sig2noise = openpiv.process.extended_search_area_piv( frame_a, frame_b, window_size=24, overlap=12, dt=0.02, search_area_size=64, sig2noise_method='peak2peak' )
File "process.pyx", line 18, in openpiv.process.extended_search_area_piv (openpiv/src/process.c:1386)
ValueError: Buffer has wrong number of dimensions (expected 2, got 3)

I have also tried with B&W version of the images but I obtain the same error message.

Any idea what goes wrong?

Cheers,
Romain