[Insight-users] Image Coordinate Directions

[Mark Foskey]

I am trying to write an input filter for a format in which the  y 
physical coordinate decreases as the  j  index increases, whereas the  x 
  and  z  coordinates move in the same direction as their corresponding 
index coordinates.  I am not sure of the best general way to indicate 
the relationship between the voxel and world coordinates.

It appears that the correct thing, according to the design of ITK, is to 
  use the three Direction vectors accessible by Set/GetDirection to 
indicate the directions of the three (voxel) coordinate axes in space. 
So the Reader code could do something like

   this->SetDirection(0, {1, 0, 0});
   this->SetDirection(0, {0, -1, 0});
   this->SetDirection(0, {0, 0, 1});

modulo corrections to the syntax.

However, calling

   grep GetDirection `find . -name "*.cxx"`

from the InsightApplications top directory yields no hits, leading me to 
believe that nobody is going to look at the direction vectors.

Is there a better, standard solution?

Thanks for any ideas,
Mark

-- 
Mark Foskey  (919) 966-1101 x245  Radiation Oncology, CB 7512
mark_foskey at unc.edu               University of North Carolina
http://www.cs.unc.edu/~foskey     Chapel Hill, NC  27599-7512