more on high speed video with varying brightness/illumination

Posted by Franklin Shaffer-2 on
URL: http://imagej.273.s1.nabble.com/high-speed-video-with-varying-illumination-tp3694724p3694726.html

I thank all who have responded.  I am looking for an image processing solution to this problem.  
I have a stack of more than 10,000 frames of particles.  The brightness (grey level) of the particles varies significantly from frame to frame, not only because of the illumination source.  
My goal is to detect and locate the centroid of most of the particles in each frame.  Here are the steps I'm using in ImageJ
1. Adjust Brightness/Contrast
2. Otsu Thresholding
3. Adjust Threshold
4. Analyze Particles

This misses most of the particles in dim images.  If anyone has any suggestions to deal with the problem of varying brightness (grey level) from frame to frame, I would appreciate your advice.
Thank you,
Frank Shaffer
USDOE NETL


>>> "Marcel Krzan PhD" <[hidden email]> 10/17/2008 3:32 AM >>>
Hello,

I work with similar (maybe no so advanced camera, but similar)
Speedcam Weinberger - Macrovis 1000 fps - with 1200x1000 pixel resolution

In our research we use various kinds of halogen illuminations - and
observe no influence of the brightness connected with the AC frequency 60
hz

Try our solutions:

Hedler-HT19s-e11  - 3 x 650W  halogen (it is common use in the
professional photography)

or halogen with the fibre wire made by Schott North America Inc. KL 1500
LCD or KL 2500 LCD

Best regards,

Dr. Marcel Krzan
"Dispersed System" research group
Institute of Catalysis and Surface Chemistry
Polish Academy of Sciences
ul. niezapominajek 8
30-239 Cracow
Poland