To generate random irregular geometry like in these images (for brainstorming art), 1) install Processing http://processing.org/download and 2) download this script I wrote for it https://github.com/earthbound19/_ebDev/blob/master/processing/by_me/rnd_irregular_geometry_gen/rnd_irregular_geometry_gen.pde, then 3) press the "play" (triangle/run) button. It generates and saves pngs and svgs as fast as it can make them. Press the square (stop) button to stop the madness. I dedicate this Processing script and all the images I host generated by it to the Public Domain. The first two images here (you may only see one image if you read a syndication of this post) are tear or contact (many images) sheets from v1.9.16 of the script. Search URL to bring up galleries of output from this script: http://earthbound.io/q/search.php?search=1&query=rnd_irregular_geometry_gen

You probably can't reasonably copyright immediate output from this script, as anyone else can generate the same thing via the same script if they use the same random seed. But you can copyright modifications you make to the output.