effrenus · December 14, 2013 19:57 · Dec 14, 2013
diff --git a/JPEG Optimization cjpeg b/JPEG Optimization cjpeg
@@ -0,0 +1,33 @@
+#!/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