Update: If you have a recent NetPBM, this is fixed.
I’d previously alluded that netpbm’s pgmnoise wasn’t as random as it could be if you called it several times in quick succession. Nerdy discussion after the break, but here’s a (perhaps slightly linux-centric) alternative:
#!/bin/sh # pgmrnoise - a more random pgmnoise; limited to 8-bit images # created by scruss on Sun Oct 12 19:36:37 EDT 2008 echo P5 echo $1 $2 echo 255 dd if=/dev/urandom bs=$1 count=$2 2> /dev/null
I just pasted the shell text in there; you’ll need to save it as a file. It works the same way as pgmnoise:
pgmrnoise width height > noise.pgm
It is limited as written to 8 bit-per-pixel output, but is a fairly trivial edit to make it 16 or more bits.
