Major and Minor axis length

[Johannes Schönberger]

Hi Anders,

there is different formulations for axis lengths and eccentricity in
literature. At the moment, I cannot recall which formulation I used when I
implemented the functions. In the end, it does not matter what scaling
factor you use, as long as it is consistent. A quick Google search reveals
this page:
https://books.google.com/books?id=4gBUz_IkkSsC&lpg=PA230&ots=mAAFbCrng_&pg=PA231#v=onepage&q&f=false
which seems to confirm my implementation.

Following the references, you should be able to figure out more about that.

Hope that helps.

Best, Johannes

On Tue, Jun 16, 2015 at 8:25 AM, Anders Prier Lindvig <aprier90 at gmail.com>
wrote:

> I have been using the scikit-image library for a segmentation task in my
> master thesis. More specifically I have used the regionprops function for
> calculation of major and minor axis length of objects. I was wondering why
> exactly, the eigenvalues are multiplied by 4, before returning the axis
> length? I realize that you multiply by 2 to get the full length, and I
> think you multiply by 2 again because of the standard deviation, but I am
> unsure about this.
>
>  --
> You received this message because you are subscribed to the Google Groups
> "scikit-image" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to scikit-image+unsubscribe at googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/scikit-image/attachments/20150616/b19e7b44/attachment.html>