Hi, I'm trying to make my own algorithm for 2d interpolation.
The upper left figure shows the data used for the interpolation. The upper right is the data interpolated with a linear method. The lower left is the result of matlab interp 2 cubic method and the lower right is an algorithm I made for cubic interpolation in 2d.
I wanted to know what interp2 does when you have data on the edge (for example the point where the X is). You need 2 points both sides to interpolate with the cubic method so what I did is interpolate linearly on the edge of the map. I'm on MATLAB 2016.
At the moment, my method uses separable convolution so I interpolate on rows first and then I interpolate on columns.
From what I understand from the code, interp2 extrapolates to be able to interpolate near edges, but I don't know which method is used to do so? Is it simply linear extrapolation?