Smoothinator is a program that can upscale low resolution gray-scale images using curve fitting. The curve fitting is done by the fitCurves program, which is a python implementation of Philip J. Schneider's "Algorithm for Automatically Fitting Digitized Curves", where I have modified the code to suit my needs.
I made this program to try to upscale the results from my topology optimizer topomax, and I would say the results look good, but I have not yet computed the actual performance of the smooth designs.
Low quality cantilever from topology optimizer Smoothened version of cantilever
