RD-curve evaluation of libjpeg/mozjpeg encoder

jpegeval.sh

#!/bin/bash

LIBJPEG=/usr/local/opt/jpeg/bin/cjpeg
MOZJPEG=/usr/local/opt/mozjpeg/bin/cjpeg
LIBJEPG_OPTS=""
MOZJPEG_OPTS=""
QRANGE=`seq 80 100`

# ImageMagick
IDENTIFY=/usr/local/opt/imagemagick/bin/identify
CONVERT=/usr/local/opt/imagemagick/bin/convert
COMPARE=/usr/local/opt/imagemagick/bin/compare
# gnuplot
GNUPLOT=/usr/local/opt/gnuplot/bin/gnuplot


if [ ! -f "$1" ]; then
    echo "usage: $0 <target>"
    exit 1
fi
INFILE=$1
IMGINFO=`$IDENTIFY -format '%m,%wx%h' "$INFILE"`
echo -e "input: $INFILE (${IMGINFO})"


if [ -d ./tmp ]; then
    WORKDIR=./tmp
else
    WORKDIR=`mktemp -d`
fi
SRCFILE=$WORKDIR/${INFILE%.*}.ppm
DATFILE=$WORKDIR/${INFILE%.*}.dat
GRAPHFILE=rdcurve-${INFILE%.*}.png

echo "convert:" `basename "$SRCFILE"`
$CONVERT "$INFILE" "$SRCFILE"
echo -e "#$INFILE\t${IMGINFO}" > $DATFILE

echo "libjpeg encoding: ${LIBJEPG_OPTS}"
for Q in $QRANGE; do
    DSTFILE=$WORKDIR/libjpeg-q$Q.jpeg
    $LIBJPEG -quality $Q ${LIBJEPG_OPTS} "$SRCFILE" > "$DSTFILE"
    RATE=`wc -c "$DSTFILE" | awk '{print $1}'`
    DIST=`$COMPARE -metric PSNR "$SRCFILE" "$DSTFILE" /dev/null 2>&1`
    echo -e "libjpeg\t$Q\t$RATE\t$DIST" >> $DATFILE
done

echo "mozjpeg encoding: ${MOZJPEG_OPTS}"
echo -e "\n\n#mozjpeg" >> $DATFILE
for Q in $QRANGE; do
    DSTFILE=$WORKDIR/mozjpeg-q$Q.jpeg
    $MOZJPEG -quality $Q ${MOZJPEG_OPTS} "$SRCFILE" > "$DSTFILE"
    RATE=`wc -c "$DSTFILE" | awk '{print $1}'`
    DIST=`$COMPARE -metric PSNR "$SRCFILE" "$DSTFILE" /dev/null 2>&1`
    echo -e "mozjpeg\t$Q\t$RATE\t$DIST" >> $DATFILE
done


echo "write: ${GRAPHFILE}"
TITLE="${INFILE%.*} (${IMGINFO})"
SCALE=$((`$IDENTIFY -format '%w' "$SRCFILE"` * `$IDENTIFY -format '%h' "$SRCFILE"`))
$GNUPLOT << EOT
set terminal png medium
set output "${GRAPHFILE}"
set title "${TITLE}"
set xlabel "Bitrate [bit/pixel]"
set ylabel "PSNR [dB]"
set key left top

plot "${DATFILE}" index 0 using (8*\$3/${SCALE}):4 with linespoints title "libjpeg", \
     "${DATFILE}" index 1 using (8*\$3/${SCALE}):4 with linespoints title "mozjpeg"
EOT