Image Optimization script

optimize-images.sh

#!/usr/bin/env bash
set -euo pipefail

declare threads=`getconf _NPROCESSORS_ONLN`

optimise () {
	declare -a exts=("${!1}")
	declare msg=$2

	for ext in ${exts[@]}
	do
		find -O3 . -type f -iname $ext | parallel "-j${threads}" "mogrify -resize 1920x1080\> -units pixelsperinch -density 72 -format webp {}"
	done

	echo $msg
}

delete () {
	declare ext=$1
	declare msg=$2

	find -O3 . -iname $ext | parallel "-j${threads}" rm -f {}
	echo $msg
}

delete_arr () {
	declare -a exts=("${!1}")
	declare msg=$2

	for ext in ${exts[@]}
	do
		find -O3 . -iname $ext | parallel "-j${threads}" rm -f {}
	done

	echo $msg
}

# Convert uncompressed formats to webp
bmps=("*.bmp","*.ppm","*.pgm","*.pbm","*.pnm") 
optimise  bmps[@] "Converted BMPs to WEBPs" && delete_arr bmps[@] "Deleted BMPs"

# Convert some more obscure formats to webp
heifs=("*.heic", "*.heif")
optimise heifs[@] "Converted HEIFs to WEBPs" && delete_arr heifs[@] "Deleted HEIFs"

# Convert PNGs to webp
png=("*.png")
optimise png[@] "Converted PNGs to WEBPs" && delete_arr png[@] "Deleted PNGs"

# Convert JPEGs to webp
jpegs=("*.jpeg", "*.jpg")
optimise jpegs[@] "Converted JPGs to WEBPs" && delete_arr jpegs[@] "Deleted JPGs"

# Limit density of webp images
webps=("*.webp")
optimise webps[@] "Optimized WEBPs"

delete "*.webp~" "Deleted Backup Files"