Re: more on high speed video with varying brightness/illumination

Posted by Robert Dougherty on Oct 17, 2008; 3:59pm
URL: http://imagej.273.s1.nabble.com/high-speed-video-with-varying-illumination-tp3694724p3694727.html

Frank,

> 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.

I'm guessing the dim images are noisy.  Perhaps apply a median filter as
step 0.5 or 1.5?  This would introduce an element of selectivity based on
spatial coherence, which Otsu thresholding seems to lack.

Bob
Robert P. Dougherty, Ph.D.
President, OptiNav, Inc.
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