Radial Distribution Module

cellprofiler

#1

I was wondering if I could some more detail about exactly what the radial distribution module measurements measure.
Here is what the manual says
1 - Fraction of total stain in an object at a given radius.
2 - Mean fractional intensity at a given radius (Fraction of total
intenstiy normalized by fraction of pixels at a given radius).

For #1, does this mean the fraction of the total area occupied by stain (is there a threshold intensity applied) or does it mean the fraction of the total stain intensity.
For #2 is there a way of calculating back out the total intensity at the given radius?

Could you please list out exactly what calculations are made by the module.

I need something to give me the fraction of the total intensity at a given radius, I am not sure if #1 does this or if it just calculates the area occupied by stain.

Please Help!


#2

Hi,

If you imagine a intensity histogram in which the bins extend from the center to the object perimeter, that gives you a good idea of what this module does. The FractionAtDistance (FracAtD) is the binned intensity values divided by sum of the binned intensity values. The MeanPixelFraction is FracAtD divided by the fraction of objects pixels at a given distance.

With that in mind:
For (1): It’s the latter, i.e, this means the fraction of the total (that is, summed) stain intensity within the object at the given radius
For (2): For the FracAtD measurement, the sum of the binned intensity values is the same as the integrated intensity of the object. So you can obtain the total intensity for a given radius by inserting a MeasureObjectIntensity module, getting the IntegratedIntensity measurement, and multiplying the FracAtD measurements by this value.

Hope this helps!
-Mark


#3

It helps me very much, thank you.


#4

Good to hear. Let us know if there any other problems!
-Mark