how to find the upper envelope and lower envelope by 2D spline interpolation of local maxima and local minima respectively?

the local maxima and minima of an image are calculated. how to do spline interpolation in a matrix

Answer 1

[Matt J]

I don't think there is a way to interpolate scattered data using splines. I'm not even sure how you'd define it. Anyway, for interpolating scattered data in MATLAB, you're pretty much limited to TriScatteredInterp.

I'm assuming you really mean it when you say "interpolation" and not "regression".