[SciPy-User] Difference in quality from different interpolation orders

[denis]

Folks,
  a non-expert addon to David's and Zach's expert comments:
splines can interpolate (go through the input data points exactly),
or smooth but not interpolate exactly.
Catmull-Rom splines interpolate, B-splines smooth more.
One can mix the two, e.g. 2/3 C-R spline + 1/3 Bspline;
there's a great paper describing this for cubic splines,
    Mitchell and Netravali, "Reconstuction filters in computer
graphics", 1988
    http://portal.acm.org/citation.cfm?id=378514

Does anyone know what splines ndimage.spline_filter uses --
interpolating ?

cheers
  -- denis

On Jun 17, 3:54 am, David Baddeley <david_badde... at yahoo.com.au>
wrote:
> I think it's a really interesting, but also really hard question, and one which
> is going to depend a lot what you're going to use it for.
>
> I suspect that one should nominally do the interpolation by fitting smoothing
> (rather than standard) splines,