intensify your emojis

gifintensifier.sh

#!/bin/bash
#
# Call this script, passing an image filename
# Creates an intensified version

convert='/usr/local/bin/convert'
realpath='/usr/local/bin/realpath'

# flight check: must have imagemagick
if [ ! $(which $convert) ]; then
	echo 'Error: `convert` required. Available via homebrew: `brew install imagemagick`.'
	exit;
fi;

# flight check: must have realpath
if [ ! $(which $realpath) ]; then
	echo 'Error: Cannot find realpath. Available via homebrew: `brew install coreutils`'
	exit;
fi;

# flight check: must pass image
if [ $# -eq 0 ]; then
	echo "Usage:"
	echo "bash ${0} <filename>"
	exit;
fi

delay=3
while [ ! $# -eq 0 ]
do
	case "$1" in
		--help | -h)
			echo "Usage:"
			echo "bash ${0} <filename>"
			echo "--help | -h  Show this"
			echo "--debug      Print some extra info"
			echo "--less       Lessen the shakyness (more delay)"
			echo "--alt        Alternate style (better for filled backgrounds)"
			exit;
			;;
		--debug)
			shift
			debug=true
			;;
		--less)
			shift
			delay=100
			;;
		--alt)
			shift
			alt=true
			;;
		*)
			fileinput=$1
			shift
			;;
	esac
done


fullpath=$($realpath "$fileinput")
filename=$(basename "$fullpath")
dirname=$(dirname "$fullpath")
plainname=${filename%.*}
extension=${filename#*.}

# verify input image
if [ ! -f "$fullpath" ]; then
	echo 'Error: input not valid'
	exit;
fi;

if [ ! -z $debug ]; then
	echo "What are we working with:"
	echo 'fileinput: ' $fileinput
	echo 'fullpath: ' $fullpath
	echo 'filename: ' $filename
	echo 'dirname: ' $dirname
	echo 'plainname: ' $plainname
	echo 'extension: ' $extension
	echo
fi

# force use of png to ensure transparency
baseframe="${dirname}/${plainname}-base.png"
frame1="${dirname}/${plainname}-frame1.png"
frame2="${dirname}/${plainname}-frame2.png"
frame3="${dirname}/${plainname}-frame3.png"
frame4="${dirname}/${plainname}-frame4.png"
suffix='intensifies'
if [[ delay -gt 3 ]]; then
	suffix='less-intense'
fi
if [ ! -z $alt ]; then
	suffix='alt-intense'
fi

gif="${dirname}/${plainname}-${suffix}.gif"

if [ ! -z $debug ]; then
	echo "What are we making:"
	echo 'baseframe: ' $baseframe
	echo 'frame1: ' $frame1
	echo 'frame2: ' $frame2
	echo 'frame3: ' $frame3
	echo 'frame4: ' $frame4
	echo 'gif: ' $gif
	echo
fi


if [ ! -z $alt ]; then


	# newimgw=$(expr $imgw + 10)
	# newimgh=$(expr $imgh + 10)

	# first, stretch the image a bit, so we have something to crop
	# convert "$fullpath" -resize '138x138>' -resize '138x138<' "$baseframe"
	# convert "$fullpath" -resize ${newimgw}x${newimgh} "$baseframe"
	# actually, stretching seems unnecessary. Perhaps I forgot an edge case?
	$convert "$fullpath" -resize '138x138>' "$baseframe"

	dims=$(convert "$baseframe" -print "%wx%h\n" /dev/null)
	imgw="$(cut -d'x' -f1 <<<$dims)"
	imgh="$(cut -d'x' -f2 <<<$dims)"
	newimgw=$(expr $imgw - 10)
	newimgh=$(expr $imgh - 10)
	if [ ! -z $debug ]; then
		echo "Dims math:"
		echo 'imgw: ' $imgw
		echo 'imgh: ' $imgh
		echo 'newimgw: ' $newimgw
		echo 'newimgh: ' $newimgh
		echo
	fi
	# -crop 128x128+5+5 : In the final step, trim the image down to max 128x128
	resize="-crop ${newimgw}x${newimgh}+5+5"
else # or
	# first, add some padding around the image, gives us room to dance
	$convert "$fullpath" -resize '128x128>' -bordercolor none -border 5 "$baseframe"
	# -resize 128x128> : In the final step, if bigger than 128x128 (>), resize down to max 128x128
	resize='-resize 128x128>'
fi

# make it dance
$convert "$baseframe" -page '+5+5' -background none -flatten "$frame1"
$convert "$baseframe" -page '+5-5' -background none -flatten "$frame2"
$convert "$baseframe" -page '-5-5' -background none -flatten "$frame3"
$convert "$baseframe" -page '-5+5' -background none -flatten "$frame4"

# gif it
# -dispose previous : don't stack frames
# -page '+0+0' : don't realign frames
$convert -dispose previous -delay "$delay" "$frame1" "$frame2" "$frame3" "$frame4" -page '+0+0' $resize -loop 0 "${gif}"

echo $gif

# cleanup
rm "$baseframe" "$frame1" "$frame2" "$frame3" "$frame4"