#!/bin/sh -e
-jpegtran -optimize -progressive -perfect -copy all "$1" |
- cjxl - "${1%.*}.jxl" -d 0 -e 9
+tmp=`mktemp`
+trap "rm -f $tmp.jpg" HUP PIPE INT QUIT TERM EXIT
+jpegtran -optimize -progressive -perfect -copy all "$1" > $tmp.jpg
+cjxl $tmp.jpg "${1%.*}.jxl" -d 0 -e 9 --lossless_jpeg=1
[ -s "${1%.*}.jxl" ]