Re: Measurement of Feret diameter

Posted by BenTupper on
URL: http://imagej.273.s1.nabble.com/Measurement-of-Feret-diameter-tp5003818p5003913.html

Hi,

On Jul 8, 2013, at 1:12 PM, Geology Guy wrote:

> Good Morning Everyone,
> The Feret's diameter that is measured is a measurement of the "maximum
> diameter" I believe and the MinFeret is also provided. I read a paper saying
> that just one Feret measurement of a non spherical particle would be
> meaningless as the Feret measurement is based on a statistical average after
> rotating the particle through all different possible angles. Does that mean
> that I have to add the Feret and MinFeret and divide by 2 to get the average
> value or what would be the best way to go about this?
>

The computation of ferets already involves rotation - you can see the details in the source code for ShapeRoi.  The rotation is divided into 2 degree increments - which is different than "all different possible angles".  Getting the latter would require a good deal of patience.

http://rsb.info.nih.gov/ij/developer/source/ij/gui/ShapeRoi.java.html

Are you looking for a representative size measurement?

Cheers,
Ben

> Thanks for your reply
>
>
>
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