Toralf Lund wrote:
Caveman wrote:
[ Long and meaningless discussion... ]
- the "real" formula computes level at point x,y based on the values of *all* the samples of the image
What you are talking about here is probably an n-degree polynomial, where n is the number of pixels or samples.
Or maybe it's n-1. But not necessarily, come to think of it; this is the highest degree possible, but you may perfectly well use n values to estimate a polynomial with an less than n-1...
Might give you good results, but it's still an approximation. And I' not sure you can automatically assume that the data will be more correct than what you get if using lower-degree polynomials within smaller regions.
- bicubic computes level at point x,y based on the values of the samples in a 4x4 vicinity of point x,y (and discards from computation all the other samples)
That would be a 3rd degree polynomial (in 2 dimensions.)
Or you could actually use e.g. linear based on 4 points (see above)
[ ... ]
Right. And all this from a small aside...
