Nice work. The triangulation is a nice structure to get to know. You might be interested in something called data-dependent triangulation. The idea is that non-conventional triangulations (i.e., not Delaunay) make for good interpolating schemas, based on assumptions such as smoothness in the color intensity profile and so on. I wrote a Master's thesis [1] about this among other things such as decimating a dense triangulation mesh in strategic ways (using edge detection).

[1] http://uu.diva-portal.org/smash/record.jsf?pid=diva2%3A85902...

[Edit: My old blog with plenty of pictures: https://femtondev.wordpress.com/ ]