I need assistance developing an algorithm to create the an effect like the images below



This is what I am trying to achieve with water


Here is the link to the sketch. http://openprocessing.org/visuals/?visualID=10846

I am thinking of creating a series of white PImages in memory and then place them at the thirteen most brightest pixels and then use some of blending algorithm to create the effect.  Then try to create a real-time algorithm.

Any pointers would be great.