Re: distance between adjacent particles

Posted by Michael Schmid on May 09, 2007; 9:30pm
URL: http://imagej.273.s1.nabble.com/distance-between-adjacent-particles-tp3699485p3699486.html

Hi France,

one method that I sometimes use is the following:
- Create one single point per particle, e.g. using
   Process>Binary>FindMaxima.
- Run an Autocorrelation (Process>FFT>FT Math correlate, do inverse)
- Use the Radial Profile Plot
   http://rsb.info.nih.gov/ij/plugins/radial-profile.html

This gives you the radial distribution function.

Ignore the peak at zero distance.
There will be also a minimum next to zero distance because you
cannot have two isolated points touching each other. This
tells you nothing important about the particle distribution.

If the particles are really randomly distributed, apart from
these two effect and statistical noise, the radial distribution
function should be flat.

Michael
________________________________________________________________

On 9 May 2007, at 22:12, Girault France wrote:

> Dear all,
> I have an image with many particles, distributed randomly. I'm  
> trying to get the average distance between a particle with all its  
> closest neighbors but not all of the particles on the image.
> Is there an easy way to do or an existing plugin that allows such  
> measurement?
>
> Many thanks,
>
> France