Author: Yea Chen yeataro@gmail.com
base on Jan Eric Kyprianidis' flowabs. (Not a perfect transplant)
Original code by Jan Eric Kyprianidis <www.kyprianidis.com> https://code.google.com/p/flowabs
" This program implements an automatic image and video abstraction technique based on the orientation-aligned bilateral and separable flow-based difference of Gaussians filters. It was written by Jan Eric Kyprianidis while working as a research scientist for the computer graphics systems group of the Hasso-Plattner-Institut at the University of Potsdam, Germany.
A detailed discussion of the implementation can be found in the ShaderX7 book (Kyprianidis & Döllner, 2009). For more details on technical aspects see (Kyprianidis & Döllner, 2008) "