[Insight-users] Mask boundary to ordered set of points

[Raghu Venkatram]

Hi Radhika,

I did something similar couple of months back
http://ct.radiology.uiowa.edu/~jiangm/courses/dip/html/node126.html

the above link gives a very simnple boundary tracing algorithm, use
the 8 connected method.

I am assuming that you have already segmented and done some edge
detection. I used the above method to get teh boundary points, to do
this you need a seed point on your edge.

Thanks,
Raghu



On Thu, 4 Nov 2004 11:00:34 +0100, Benjamin King
<king.benjamin at mh-hannover.de> wrote:
> Hi Radhika,
> 
> I needed such a thing and made it myself als follows:
> 
> 1) Find bounding box of the object, cut with itk::RegionOfInterestImageFilter
> 2) Erode
> 3) Get border pixels by subtracting the erosion from the original
> 4) Iterate the result image and push all points in a std::vector
> 
> I iterated the whole region, but probably you can use a variant of
> itk::FloodFilledFunctionConditionalConstIterator as well.
> 
> > Or is there any function, where if you start from a boundary point, you
> > can move in a specified direction (clockwise or counterclockwise) and
> > get an ordered set of indices visited?
> This requires a border that is equivalent to a circle. Only two-dimensional
> objects with just one component, no holes and no thin (i.e. one pixel wide)
> areas meet this requirement. I don't think, there is a special class in ITK
> for those.
> 
> Hope it helps,
>   Benjamin
> 
> --
> Benjamin King
> Institut für Medizinische Informatik
> Medizinische Hochschule Hannover
> Tel.: +49  511  532-2663
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>