[Insight-users] SoftwareGuide.pdf is ready.

[Simon Warfield]

Hi Luis,

> http://public.kitware.com/Insight/Web/HTML/SoftwareGuide.pdf
> 
> Among other things, you will find:
> 
> - A complete description of the data representation
>   classes: Image, PointSet, Meshes.
> - Description of the most relevant image filters
> - Description of the Input/Output architecture
> - The Image Registration Framework
> - Various Segmentation Algorithms.
> 
> 
> Please let us know if you have any questions.

  I read over it rather quickly trying to understand the relationship
between a point in space and a voxel in an image. Perhaps you could clarify
section 4.1.4 regarding origin and spacing  (page 34)
``These coordinates correspond to the position of the first pixel of the image with respect to an arbitrary reference system in physical space...user's
responsibility [to keep it consistent]'' 
     (there is a typo in this section by the way)


  Just where in the voxel does the registration and interpolation framework
understand the coordinate to point to ?  the center of the voxel or one of
the corners of the voxel ?
  Or is this up to the user to choose ?
  
Chapter 5 doesn't seem to address it.

7.7.1 isn't completely clear.
``NearestNeigbhorInterpolateImageFunction simply use the intensity of
        ^^^^^^^^ typo by the way
the nearest grid position. That is, it assumes that the image intensity
is piecewise constant with jumps mid-way between grid positions. This
interpolation scheme is cheap as it does not require any floating point
computations.''

  Does this imply that voxels extend + and - 0.5 times the spacing from 
each grid position ? That is, each grid position is intended to be at the
center of a voxel, and similarly the origin is intended to point to the
center of a voxel.

  How does this compare to the VTK scheme ?  How are origins and coordinates
mapped between ITK and VTK in the various ITK*VTK filters ?

-- 
Simon