JPEG Optimization cjpeg

#!/bin/bash

TMPDIR="/tmp/psnr_tmp"
PSNR_LEVEL=40

mkdir $TMPDIR

ls *.jpg | while read file; do
	echo $file
	echo "-----------------"
	name=${file%%.*}
	actualsize=$(du -b "$file" | cut -f 1)
	djpeg -pnm $file >$TMPDIR/$name.pnm
	for q in {60..90..1} ; do
		echo -ne "Process quality: $q"\\r
		cjpeg -quality $q $TMPDIR/$name.pnm >$TMPDIR/$file
		djpeg -pnm $TMPDIR/$file >$TMPDIR/$name_$q.pnm
		psnr=$(pnmpsnr $TMPDIR/$name.pnm $TMPDIR/$name_$q.pnm 2>&1 >/dev/null | awk '/Y  color/ {print $5}')
		if [ $(echo "$psnr>=$PSNR_LEVEL" | bc) -eq 1 ]; then
			jpegtran -copy none -optimize -outfile $TMPDIR/$file $TMPDIR/$file
			compressedsize=$(du -b "$TMPDIR/$file" | cut -f 1)
			if [ $compressedsize -lt $actualsize ]; then
				mv $TMPDIR/$file ./compressed/
				echo "Quality: $q Result: filesize $actualsize => $compressedsize"
			else
				echo "Can't be more lossy comressed with current PSNR level: $PSNR_LEVEL"
			fi
			break
		fi
	done
done

rm -r $TMPDIR