trap "rm -f $tmp" HUP PIPE INT QUIT TERM EXIT
pams=()
-djxl2pam="( djxl --quiet {} ppm:- || djxl --quiet {} pgm:- )"
+djxl2pam="( djxl --quiet {} - --output_format ppm || djxl --quiet {} - --output_format pgm )"
if [[ -n "$NOALT" ]] ; then
for img ($imgs) {
[[ -r preview/$img.webp ]] || pams=($pams $img)