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

[Benjamin King]

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