Optimizing images for Google PageSpeed.

image_optimizer.sh

#!/bin/bash
# Author:       Valentin Popov
# Email:        info@valentineus.link
# Date:         2018-09-10
# Usage:        /bin/bash image_optimizer.sh /path/to/input
# Description:  Optimizing images for Google PageSpeed.

# Updating the Environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
export PATH="$PATH:/usr/local/scripts"

exec 1> >(logger --stderr --tag IMAGE_OPTIMIZER) 2>&1
echo "Script started"

if [ "$1" ]; then
  INPUT="$(readlink --canonicalize-missing "$1")"
  if ! [ -d "$INPUT" ]; then
    echo "Destination directory does not exist"
    exit 1
  fi
else
  echo "No INPUT parameter"
  exit 1
fi

if ! [ -x "$(command -v jpegtran)" ]; then
  echo "jpegtran is not installed"
  exit 1
fi

if ! [ -x "$(command -v pngquant)" ]; then
  echo "pngquant is not installed"
  exit 1
fi

echo "Create a backup..."
DIRECTORY="$(basename "$INPUT")"
tar -cjSf "${DIRECTORY}_backup_$(date "+%G_%m_%d_%H_%M").tar.bz2" "$DIRECTORY"

echo "Processing of JPG images..."
find "$INPUT" -iname "*.jpg" -type f -print | while read FILE; do
  echo "In process: $(basename "$FILE")"
  jpegtran -copy none -optimize -outfile "$FILE" "$FILE"
done

echo "Processing of PNG images..."
find "$INPUT" -iname "*.png" -type f -print | while read FILE; do
  echo "In process: $(basename "$FILE")"
  pngquant --force --output "$FILE" --quality 65-80 --speed 1 --strip "$FILE"
done

# End of work
echo "Script has been successfully completed"
exit 0