Hi,
I think the usefulness of the rebin function is to be simple and fast,
and the best would be to implement it in the core numpy, as a simple
method for smoothing and reshaping, without the need of using scipy.
For anything more sophisticated, the ndimage module as you suggest
should be used.
I once wrote a generic n-dimensional binning routine in C that I could find if
anyone is interested in integrating it into numpy... it didn't do size
increases though... and I think I implemented it so that binning by a
non-divisible factor trimmed the extras. It was very-very fast though.
