"If I may ask............what did you use to break up the populations?"
Yossam, I used two stacked voronoi billows power fractals as the density mask. One masks and also feeds the other. All the scales of the bigger one are set near the 150-180 meter range and the smaller scales are is 70-80 meter range. Contrast in both is pushed to 3 and color offset is adjusted below 0 to favor more black. This gives distinct white blobs surrounded by black.
