[Insight-users] Chan and Vese Internal & External Term in the levelsetsv4 framework?

[Arnaud Gelas]

On Thu, Mar 22, 2012 at 11:27 AM, tomtom <ms.rit at web.de> wrote:

> Ok, I have tried that.
>

Cool


> One thing I wonder about, is: The area is always expanding.


I can only assume you work in 2D... In the dense case means are computed on
the whole image, and it should split the image into two clusters of pixels
with similar pixel intensities...
It is hard to say why it keeps on expanding on your case without looking at
the image :)...


> Shouldn't it be
> the case that it "adopts" at some sites, by "shrinking"?


Depending on your image, it should expand, shrink at different locations.
Note that in the dense case (without any curvature regularization, it
should converge after several iterations assuming the step size is not too
small).


> Or is that a
> question of choosing the right parameters?
>


I would recommend you first try to segment without any curvature
regularization and make sure there are only 2 clusters of pixels in your
image. Then try with lambda_in and lambda_out = 1. Then adjust these two
parameters based on your image (if needed). Once you get a results close
enough to the expected results, you can start playing with the
regularization...


> Again, thanks a lot for being so patient.
>

You're welcome!

Best,
Arnaud


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