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Re: particle analysis-Feret diameter

Posted by K. Kachrimanis on Nov 27, 2005; 8:57am
URL: http://imagej.273.s1.nabble.com/particle-analysis-Feret-diameter-tp3704371p3704377.html

If this is the maximum Feret and it is selected from all Ferets measured, then the only thing missing is to report the minimum and a mean Feret also. Then the system would be complete and better than any commercial image analysis package. By the way, about shape descriptors based on Ferets, I realized that the aspect ratio (among maany other shape descriptors), as well as the projected area or circle equivalent diameter is available in the 'Shape descriptors" plugin by Gary Chinga. So, perhaps it would be a good idea to incorporate that plugin in the basic package.
It seems that so far, the "macroshape" descriptors are more or less complete in ImageJ, a "microshape" descriptor is also available (fractal dimension), and visual texture is also possible to measure. The only thing missing is some "mesoshape" descriptors (like robustness and largest concavity index) as descriped in: Pons et al., Particle morphology: from visualization to measurement, Powder Technol., 103 (1999) 44-57.

Regards,

K.Kachrimanis.


----- Original Message -----
From: "Philippe Grosjean" <[hidden email]>
To: <[hidden email]>
Sent: Sunday, November 27, 2005 8:22 AM
Subject: Re: particle analysis-Feret diameter


> Hi all,
>
> If my understanding of Feret diameter in ImageJ is correct, this is the
> *maximum* one, calculated at various angles. But how many angles are
> considered? I browse the source code rapidly, and found several
> getFeretsDiameter() functions (ij.gui.OvalRoi, PolygonRoi, Roi &
> ShapeRoi). In particular, in ShapeRoi, you also have a getMinFeret()
> function, but it is commented out. Apparently, shape is rotated every
> degree in these function?
>
> Anyway, I join Mr Kachrimanis in a request for reporting also the
> *minimum* (and possibly the *mean*) Feret diameter. A lot of derived
> measurements can be done if you have those additional measurements. My
> plan for the future is to patch ImageJ to report those. This should not
> be too difficult... unfortunatelly, I am not a Java programmer and have
> little free time now. So, this is a pain for me, and I will not do it
> before one year, or so (I still hope to see it added in a future version
> of ImageJ).
>
> Best,
>
> Philippe Grosjean
>
> P.S.: by the way, many thanks for adding 'Skew' and 'Kurt' in the
> particle analyzer in the latest version of ImageJ!
>
> ..............................................<°}))><........
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