Good Vib3s
Pc bench mark [userbenchmark.com]
#!/bin/sh
for jpg; do
png=${jpg%.jpg}.png
printf 'converting "%s" ...\n' "$jpg"
if convert "$jpg" jpg.to.png; then

mv jpg.to.png "$png"

printf >&2 'jpg2png: error: failed output saved in "jpg.to.png".\n'
exit 1
fi
done
printf 'all conversions successful\n'