[Insight-developers] Methods for comparing meta-data with tolerance

[Brad King]

On 06/22/2011 02:53 PM, Bradley Lowekamp wrote:
> That still doesn't answer where to put almost equal vector, point,
> and matrix... perhaps in the classes themselves?

An "almost equal" test is typically context-dependent.

My understanding is that the goal of this comparison is to determine
whether it is safe to do index-space filtering of two inputs, as in
the "add" image filter.  Another approach is to carry some kind of
unique meta-data tag associated with a data set when it is first read
and propagated through filters that don't touch the meta-data (origin
and spacing).  Index-space filters would work only if all inputs have
the same tag.  A new filter could handle the "almost equal" test using
application-defined parameters in order to set matching tags on
images from different sources.

> Is this an endorsement of using an assumption that we have IEEE
> floating point numbers, and can assume to be doing bit-wise comparisons?

It was just a link for reference.

-Brad K