Lote jpg a png Lote png a jpg Lote jpg2png Lote png2jpg

Haz un pequeño script, fácil de implementar.

 jpg2png

#!/bin/bash
# convert jpeg files to png files
# usage: jpg2png <file>...

for f in "$@"
do
    sips -s format png --out "${f%.*}.png" "$f"
done

png2jpg

#!/bin/bash
# convert png files to jpeg files
# usage: png2jpg <file>...

for f in "$@"
do
    sips -s format jpeg --out "${f%.*}.jpg" "$f"
done