Re: particle analysis-Feret diameter

On Monday 28 November 2005 13:47, r.ghezzo@xxxxxxxxxxxxxxx wrote:
> I think that you have only one feret diameter, the maximum.
> draw the convex hull and then compute all the distances between the points
> in the hull.

Yes, that is what I described earlier and what is implemented in the 
Particles8_Plus plugin.

> What is the minimum? The smallest size hole through which the particle can
> pass?

Well, not according to the definition of Feret diameter given yesterday.

> How about a banana? Does anybody know of an algorithm that can 
> compute the smalles feret for an egg and for a banada?

The algorithm should be the same, but the smallest hole through which the 
particle can pass is not necessarily the same as the minimum Feret.
The breadth is not the same either, although it is the smallest hole neded to 
pass the particle if you push the particle in the direction of the maximum 
Feret.

Cheers,

Gabriel