[Insight-developers] Direction Validation and Testing

[Bill Lorensen]

Folks,

As you can see from recent activity on the list (and the slicer3
developers' list) there are lots of questions regarding the handling
of direction cosines (orientations) in itk. We need a rigorous
approach to document, validate and test the directions, origins and
spacing of our images, readers, writers and algorithms.

Since I am to blame for the current implementation of directions in
ITK, I will set up a wiki page (TBA) that will address this important
issue.

Some of the issues we have to address:

1) Better documentation of the ITK coordinate system, directions,
origin and spacing.
2) For each ITK readers/writers (aka ImageIO) represent  coordinate
system, directions, origin and spacing.
3) A repository of VALIDATED test data with known meta data:
coordinate system, directions, origin and spacing.
4) A methodology to validate and test the meta data. This methodology
must include 3rd party (non-ITK) validation of the data.

and other concerns I am sure.

Products of this effort should include:

1) Unambiguous documentation of ITK's  coordinate system, directions,
origin and spacing.
2) An Insight Journal publication summarizing and documenting this effort.
3) Updates to the Insight Users Manual to describe the results.

Let's discuss this for a few days on the list before I set up the wiki page.

Bill