Nothing serious, just a fun iPad app for a Sunday.
The many filter apps that process photos to create various effects have become ubiquitous. Old film effects, sepia, Polaroid, old time movie, painting, etc., etc., etc. There is a filter for everything. Some of these have often been accused of existing solely to make bad photos somehow cool. An accusation that probably has more than a bit of truth behind it.
The painting process uses an edge detection filter first, extracting the structure of the photos. Each of the various presets has dramatically different settings for this edge detection. The app then paints in the selected colors to fill in the painting. The process is animated, watching this can be rather fun.