[Insight-developers] ITK code style

[Zachary Pincus]

Hello,

I'm working on a class that I think I might submit for inclusion in 
ITK. (Specifically, a class that calculates the projection of an image 
into the space described by an orthonormal basis set, e.g. the output 
of PCA analysis).

Anyhow, I had a couple of questions on what I ought to do to conform to 
ITK's style, etc.

First, a CastImageFilter will be needed for this computation, except in 
the case when the template output and input image types are the same. 
To what extent does/should ITK code try to detect these cases and skip 
unnecessary steps? (And if this is recommended, is there a good 
mechanism for doing so? All I can think of is a templated function 
AreTheSame<TypeA, TypeB>() that returns false except in the few special 
cases I implement manually... And that seems a bit nasty.)

Second, my class needs basically all the output from a 
PCAShapeModelEstimator. Projecting into a space described by a basis 
set is a general task, but from the ITK perspective, this pretty much 
is only necessary in the PCA case. Anyhow, I could have my class take 
as input either (a) a series of images that consist of a portion of the 
output from a PCAShapeModelEstimator, or (b) the class could just take 
a reference to the PCAShapeModelEstimator itself. The latter option is 
attractive, since it will be impossible for users to do the wrong thing 
and send the wrong part of the Estimator's output to my class. But it 
seems a bit at variance to the way things are done in ITK. Does anyone 
have guidance for this case?

Thanks,

Zach Pincus

Department of Biochemistry and Program in Biomedical Informatics
Stanford University School of Medicine