optimg.sh

#!/usr/bin/env sh
#
# This script automates images optimization
# is mainly used by a developer who manually
# can execute it when adding new images to the
# project
#
# Download and compile following binaries:
#
#   - [jpegtran](http://www.ijg.org/)
#   - [pngcrush](http://pmt.sourceforge.net/pngcrush)
#   - [OptiPNG](http://optipng.sourceforge.net/)
#   - [pngout](http://advsys.net/ken/utils.htm)
#   - [advpng](http://advancemame.sourceforge.net/comp-readme.html)
#

SCRIPTPATH=$(readlink -f "$0")
# Get directory path of this script
SCRIPTDIR=$(dirname "$SCRIPTPATH")

# Set path to directory with images
IMAGESDIR="$SCRIPTDIR/app/assets/images"

##################
# Optimize JPEGS #
##################
if command -v jpegtran > /dev/null 2>&1
then
  echo "Optimizing JPEG images"
  find $IMAGESDIR \( -name "*.jpg" -o -name "*.jpeg" \) -exec jpegtran -copy none -optimize -outfile '{}' '{}' \;
else
  echo "Hmm, you're missing JPEGTRAN. I recommend you install it for best result"
fi

#################
# Optimize PNGs #
#################
if command -v pngcrush > /dev/null 2>&1
then
  echo "Optimizing PNG images using PNGCRUSH"
  for png in $(find $IMAGESDIR -name "*.png")
  do
    pngcrush -reduce -brute -q $png $png-optimized && mv $png-optimized $png
  done
else
  echo "Hmm, you're missing PNGCRUSH. I recommend you install it for best result"
fi

if command -v optipng > /dev/null 2>&1
then
  echo "Optimizing PNG images using OptiPNG"
  find $IMAGESDIR -name "*.png" -exec optipng -o7 -q '{}' \;
else
  echo "Hmm, you're missing OptiPNG. I recommend you install it for best result"
fi

if command -v pngout > /dev/null 2>&1
then
  echo "Optimizing PNG images using PNGOUT"
  for png in $(find $IMAGESDIR -name "*.png")
  do
    pngout $png -q -y -k0 -s0
  done
else
  echo "Hmm, you're missing PNGOUT. I recommend you install it for best result"
fi

if command -v advpng > /dev/null 2>&1
then
  echo "Optimizing PNG images using ADVPNG"
  for png in $(find $IMAGESDIR -name "*.png")
  do
    advpng -z -4 $png
  done
else
  echo "Hmm, you're missing ADVPNG. I recommend you install it for best result"
fi