Thanks very much for the comprehensive explanation. It should have occurred to me to try to import raw data into GIMP.
I can’t post an image here but it worked great.
here’s a different command I found which passes the random directly to an image.
rawtoppm -rgb 512 512 < /dev/random| pnmtopng > random$(date +%Y%m%d%H%M%S).png
