optimize-images.sh

#!/bin/bash

# stop on first error
#set -e

# match patterns in a case-insensitive fashion when performing matching while executing case or [[
shopt -s nocasematch

RESIZE=""
TRIM=""
ORIENT=""
QUAL=50
COPY_EXIF=""
TGT=""

while getopts "hd:ms:toq:e" OPT; do
	case $OPT in
		d)	TGT="$OPTARG/"
			;;
		m)	[ "$RESIZE" ] && {
				echo "$0: Options -m and -s are mutually exclusive." >&2
				exit 1
			}
			RESIZE="2560x1600"
			;;
		s)	[ "$RESIZE" ] && {
				echo "$0: Options -m and -s are mutually exclusive." >&2
				exit 1
			}
			RESIZE="$OPTARG"
			;;
		t)	TRIM="-fuzz 20% -trim +repage"
			;;
		o)	ORIENT="-auto-orient"
			;;
		q)	QUAL="$OPTARG"
			;;
		e)	COPY_EXIF=y
			;;
		h)	echo "
optimize-images -- makes your image storage needs more optimistic

Author: Vlada Macek <macek@sandbox.cz>, 2016-2017

The current files are always left intact. First the subdirectory
__optimized...  (name followed by short labels of operations) for targets is
created, by default in the current directory.

Images impossible to shrink are hard-linked to target directory, as well as
animated GIFs. Errors are stored in __errors subdirectory.

All processing is done in parallel, spread to the number of CPUs detected by
the nproc command.

Requirements:

  'convert' and 'identify' from ImageMagick
  mocjpeg in '/opt/mozjpeg/bin/cjpeg' from https://github.com/mozilla/mozjpeg
  'exiftool'

Options:

  -d PATH          - don't create target subdir here, but under PATH
  -s WIDTHxHEIGHT  - the rectangle in which the resulting image should fit
  -m               - same as  -s 2560x1600
  -t               - crop out the border of pixels having roughly the same color
                     around the image
  -o               - automatically orient image (reads and resets the EXIF image
                     profile setting 'Orientation')
  -q QUALITY       - change the default output JPEG quality 50 to QUALITY
  -e               - use ExifTool to copy the EXIF data to target file, remove
                     embedded thumbnails
  -h               - this help
"
			exit 1
			;;
	esac
done

TGT="${TGT}__optimized_q$QUAL"

[ "$RESIZE" ] && {
	TGT+="_$RESIZE"
	RESIZE="-resize $RESIZE>"
}
[ "$TRIM" ] && TGT+="_trim"
[ "$ORIENT" ] && TGT+="_orient"
[ "$COPY_EXIF" ] && TGT+="_exif"

echo "# Target: $TGT"

ERRS="$TGT/__errors"

[ "$1" ] && mkdir "$TGT" || exit 0

[ "$CPU_NUMBER" ] || CPU_NUMBER="`nproc 2>/dev/null || echo 1`"

CONVERTOR="convert - $ORIENT $TRIM $RESIZE tga:-"

OPTIMIZER="/opt/mozjpeg/bin/cjpeg -targa -optimize -progressive -sample 1x1 -quant-table 2 -quality $QUAL"

while [ "$1" ]; do

	# only take non-empty regular files or symlinks
	[ -f "$1" -a -s "$1" ] || { shift; continue; }

	{
		TMPF="/tmp/.optimize-images.tmp.$#.$$"

		if [[ $1 =~ \.gif$ && "`identify -ping "$1" | wc -l`" -gt 1 ]]; then
			echo "[$# left] $1 - animated GIF, hard-linking original"
			ln -f "$1" "$TGT/$1"
		else

			$CONVERTOR < "$1" | $OPTIMIZER > "$TMPF"

			TGT_SIZE="`stat -c %s "$TMPF"`"
			if [ "$TGT_SIZE" = 0 -o -z "$TGT_SIZE" ]; then
				echo "ERROR, target file is empty or so, hard-linking original to $ERRS."
				mkdir -p "$ERRS"
				ln "$1" "$ERRS"
			else
				PERCENTAGE=$((100*$TGT_SIZE/`stat -c %s "$1"`))
				if [ "$PERCENTAGE" -lt 90 ]; then
					echo "[$# left] $1 - ${PERCENTAGE}%"

					TF="$TGT/${1##*/}"
					if [[ ! $TF =~ \.jpe?g ]]; then
						TF+=".jpg"
					fi

					mv -i "$TMPF" "$TF"

					if [ "$COPY_EXIF" ]; then
						exiftool -TagsFromFile "$1" -all:all -ThumbnailImage= -overwrite_original "$TF"
					fi

					touch -r "$1" "$TF"
				else
					echo "[$# left] $1 - ${PERCENTAGE}%, not successfull - hard-linking original"

					ln -f "$1" "$TGT/$1"
				fi
			fi
		fi

		rm -f "$TMPF"
	} &

	while true; do
		joblist=(`jobs -p`)
		if [ ${#joblist[*]} -ge "$CPU_NUMBER" ]; then
			wait -n
		else
			break
		fi
	done

	shift
done

wait