Thread Subject: interpolating 3D data

Hi

I have a set of voxels representing a curve in 3d (space curve)
e.g. 5 voxels at [1,1,1], [2,3,4], [5,4,7],[10,11,8] and [9,15,15].

I want to interpolate this curve and resample the data at, say, 8 evenly space points along the curve (i.e. equally spaced in terms of the curve length). I want to do this so that I can compare the points to 8 evenly spaced points on another curve.

Apologies if this is a basic question but I haven't been able to find a decent answe

Thanks
Ben

I still can't find a way to solve this problem.

cscvn seems to be a way of creating a cubic spline from points on a space curve but this is not ideal because it is interpolative rather than approximate and the sample points are noisy.

The second part of the problem involving resampling:
Once I've got the ppform of a space curve using say cscvn, how do I sample at equal distances along this space curve?

"Ben Irv" <i.benjamin@ymail.com> wrote in message <hde1pf$fhc$1@fred.mathworks.com>...
> Hi
>
> I have a set of voxels representing a curve in 3d (space curve)
> e.g. 5 voxels at [1,1,1], [2,3,4], [5,4,7],[10,11,8] and [9,15,15].
>
> I want to interpolate this curve and resample the data at, say, 8 evenly space points along the curve (i.e. equally spaced in terms of the curve length). I want to do this so that I can compare the points to 8 evenly spaced points on another curve.
>
> Apologies if this is a basic question but I haven't been able to find a decent answe
>
> Thanks
> Ben

"Ben Irv" <i.benjamin@ymail.com> wrote in message <hdgvsm$v6$1@fred.mathworks.com>...
> I still can't find a way to solve this problem.
>
> cscvn seems to be a way of creating a cubic spline from points on a space curve but this is not ideal because it is interpolative rather than approximate and the sample points are noisy.
===================

You need to define a model for the curve, and apply a curve fitting algorithm to this model, e.g. fro the curvefitting toolbox