Inverting Images Color

[Mehrdad]

Hi,

This will sound like a very basic question but I'm new with PIVlab. So as long as I should have bright particles on dark background, is it possible to invert the whole set of images color in PIVlab? I saw that it's possible when you are importing a movie and extracting images from that but my data is just images and their colors are opposite, I mean I have dark particles on bright background.  
Your help is really appreciated.

[Tobi]

I had a similar situation (http://pivlab-time-resolved-digital-particle-image-velocimetry-tool-f.33690.n7.nabble.com/Particle-Density-and-Color-td13.html). But in my experience I had similar or even better results with dark particles on a bright background. But I guess this might depend on your setup.
If you, however, still want to invert your images, I would recommend the program IrfanView. There, open your image and press B, add all images to the queue, set the special option "create negative" (or similar). Choose your output destination and hit "start". Done :)

[Mehrdad]

Thank you Tobi,

I tried inverting my images with some other apps and testes PTVlab, but it seems this is not what i'm looking for ;)
It's too slow! I'm looking for implelementing IDL particle tracking method in MATLAB and compare the results between these two and find out which one is faster and much more precise. if you have any idea just let me know ;)