# How to get ImageTransformation to not compute the function at *every* pixel

I am using ImageTransformation with a slow function. Is there a way to get ImageTransformation to compute the function at only a few pixels, and then interpolate the function values for pixels in between?

For example, if $f((0,0))=(1,0)$, and $f((0,0.1))=(.9,.9)$, then it would assign the pixel at $(0,0.05)$ to the pixel at $(.95,.95)$.

Note that it should using every pixel of the input image (if warranted), it just shouldn't calculate the function for each pixel of the output image.

• How about remapping? – J. M. will be back soon Apr 9 '18 at 2:22
• @J.M. maybe. It looks like some sort of interpolation function might work too. – PyRulez Apr 9 '18 at 16:03