[Insight-developers] Octree representation

[Kent Williams]

In order to further a project Hans Johnson is working on, I implemented=20
reading and writing the BRAINS2 Octree mask files.  This amounts to about=
 90%=20
of a Image to Octree filter.=20

The last 10% would comprise

1. Would Octrees be SpatialObjects?  In other words is there any other it=
k=20
hierarchy of which Octree would be a more appropriate citizen?

2. With respect to image representation, Octrees quantize pixel colors --=
 that=20
being one application of Octrees, to reduce the color depth of images.  W=
hat=20
I'm thinking would be the most generally useful would be to 1) Have the=20
number of discrete colors be a template parameter.  2) Have the color=20
quantizer be a user-defined functor.

3. What exposed function would be most useful?  An iterator to facilitate=
=20
rendering would be useful, and the usual Spatialobject methods come to mi=
nd.

4. I had a look at the KD trees and wasn't really seeing much in the way =
of=20
commonality with the image octree.  If there is some way to put these two=
=20
tree types in a common framework I'm all for it though...

I am by no means an image processing expert -- I'm just learning as I go=20
along, so any guidance on making this a useful addition to ITK is welcome=
=2E