Posts

Major update: PIVlab 2.0

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In the past, it happened quite often that the user interface of PIVlab was not displayed correctly on Mac computers. So I decided to completely reprogram the user interface "by hand" (that means without using Matlabs built-in GUI IDE called "GUIDE"). It was quite some work, but I believe PIVlab is now future-proof and easier to maintain. GUIDE was crashing pretty often in the last months, making enhancements very difficult.



So these are the changes:GUI rewritten from scratch, should now be displayed correctly on all operating systemsAdded prefernces in the menu: You can change the panel width of the UI if the UI elements are not scaled correctly.Changed "Load external mask": You can now make masks outside of PIVlab and save them as black-and-white TIFs. When you import these masks, then white will become a masked area and black is non-masked area.Added TECPLOT file format for export.Background subtraction GUI only worked with grayscale images --> fixed…

Order a book about PIVlab!

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I still have a number of my dissertation books, it contains an extensive chapter on PIVlab. You can order a copy for 3 Euros + shipping (the money will be used to add to my Paypal money pool which will one day be used to renew my Matlab license).



The beauty of PIV cross-correlation!

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Do you like cross-correlation? You should when you visited this website...


PIVlab Update v1.50

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This update brings some new features and performance enhancements:

'Repeated correlation' I added the option 'repeated correlation'. I got the idea while I was working with another software (PIVview). 'Repeated correlation' can enhance your data yield when you are working with very noise or gernerally bad PIV images. It does the cross-correlation not only once per vector, but 5 times in total. Each time, it slightly shifts the interrogation windows (the distance depends on the size of your interrogation area, but it's about 5-10 pixels). This happens during each pass in a multipass analysis. In the end, it multiplies the 5 resulting matrices, which results in less noise an a very clear peak. But it also takes about 3 times longer to calculate...

Background elimination The next big addition is the background elimination GUI. If you have recorded a longer time series of image data, it makes sometimes sense to calculate the average of all images, and subtract…

600 citations on Google Scholar!

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https://scholar.google.de/citations?user=IcQ11w4AAAAJ
Thank you dear users of PIVlab for making this software pretty popular!
I will keep on improving the features whenever possible.

Slow motion of clothes in a drying machine...

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One PIVlab user wanted to analyse the motion of clothes in a drying machine. He had some problems with his setup, so I decided to check on my own if an analysis would actually work. Surprisingly, it works pretty well!

The original slow motion footage was taken from Youtube:


And this is the analysis:



Keep in mind that this is a very quick and dirty analysis, made with footage that was not meant to be analysed by PIV at all...

PIVlab Update 1.43

Bug fix: When displaying a velocity histogram, older versions did include masked areas under some circumstances. This is fixed in v 1.43

Added example: How to generate masks outside of PIVlab (external_mask_example.m).

Minor enhancement: Calculation speed test now tests speed for small to large interrogation areas.
Download here: http://www.mathworks.com/matlabcentral/fileexchange/27659-pivlab-time-resolved-particle-image-velocimetry-piv-tool