PIVlab update v2.38

I made two updates to PIVlab in the last weeks, the latest release is 2.38. The following things were added:

  • Video import functionality: PIVlab can directly work with video files now. Videos are not converted, but frames are directly accessed from the video stream.
  • Vorticity direction was inverted (positive is now ccw)
  • *.png files can be imported now
  • The correlation coefficient is available in the derived parameters panel. It might be used as a measure for the quality of an analysis. I tested several different things, including correlation peak height vs. mean signal strength and ratio of first to second peak. I might make these available later, when I am played around with the data a bit more.
  • Added the PIVlab Quickviewer, an additional GUI that helps to quickly tweak the setup of your experiment while you are recording your images.
  • Image histograms are automatically optimized to get a better display. This can be disabled in "Modify plot appearance"
The correlation coefficient

PIVlab Quickviewer. Top left: ROI, top right: displacements, bottom right: displacement histogram, bottom left: correlation coefficient.

Video importer. You can select start and end frame, and also decide to reduce the frame rate. A video preview is displayed.


Popular posts from this blog

PIVlab 3.00 released

Image
  I have just released PIVlab 3.00. There are several changes in the way the graphics are drawn, the way the data is exported and the way it interacts with masks / calibration and region of interest: New graphics: Transparency, masks are transparent, only ROI is opaque Colorbar is now outside the plot for much improved readability Export image data as .mp4 and as .png image Completely new mask handling, allowing much easier mask creation / modification. Mask stay editable all the time. Much easier to create holes in masks Mask operations like shrink/grow/simplify/subdivide/optimize Automatic mask generator, capable of automatic masking of bright areas / dark aread / low-contrast areas. Possibility to add more automatic mask generators in the future Mask import (of user generated masks) heavily improved Matlab Online fully supported New line extraction and area extraction interface: More straightforward and faster. Better interaction Natural file name sorting when importing image fi...
Read more

Comparison of OpenPIV and PIVlab

Image
Since quite a while, I benefit from discussions with the main developer of OpenPIV (Prof. Alex Liberzon  from Tel Aviv University) and other people that contribute to OpenPIV. It is almost a bit like a cooperation, as we share thoughts on different topics, and Alex is really into practical and theoretical PIV application. I think we have a very friendly rivalry in developing useful PIV software. The results are available here:  https://github.com/alexlib/openpiv_pivlab_von_Karman_data You will notice that they are very noisy. But we intentionally decided to make the analysis very challenging for our software. The final interrogation area is e.g. only 6*6 pixels, and no smoothing is allowed. I don't really see a difference between OpenPIV and PIVlab, which is probably a good sign. It might be interesting to include commercial software too in this comparison in the future. By the way: Happy New Year to all PIVlab users (and of course all OpenPIV users too ;-D). The year 2020 has...
Read more

Optical flow in PIVlab

Image
Welcome wOFV (wavelet-based optical flow velocimetry) to the family of open-source and easy to apply velocimetry algorithms! I released the beta yesterday evening (just before leaving to holidays 😀): Optical flow in PIVlab, see the video above for some comparisons to classical PIV. Download here: https://github.com/Shrediquette/PIVlab/releases Implemented by Bryan E. Schmidt, Gauresh Raj Jassal from Flow Physics and Imaging Laboratory at case.edu and me.
Read more