Example using BoofCV. To create this image I use two render targets, I clear them black and draw white shapes on each. Then I apply blur, and finally use BoofCV to extract the contour of the blurry shapes. I extract one contour from each render target and draw them with different fill colors.
I created it as part of an exercise in which 3 people drew images with pen and paper, passing the image to the next person who would describe it, then passing the description to the next one who would code it. You can see the images in this poster.