#!/bin/sh
# Lossy image compression using ImageMagick
# Tries to eliminate artifacts
while true
	do case $1 in
		(-o) out="$2"; shift 2;;
		(-q) quality="$2"; shift 2;;
		(*) break;;
	esac
done
out="${out:-$1-shrinked.jpg}"
test $# -eq 0 && echo "Usage: $0 [-q quality (default 85)] [-o outfile] <images...>" && exit 1
magick "$@" -auto-orient -strip -interlace Plane -define jpeg:dct-method=float -sampling-factor 4:2:0 -gaussian-blur 0.05 \
	-quality "${quality:-85}" "$out"
printf "Shrinked $1(%s) to $out(%s) - reduced to %s%%\n" \
	$(stat --format "%s" IMG_20211124_115930.jpg IMG_20211124_115930.jpg-shrinked.jpg | numfmt --to=iec-i --suffix=B) \
	$(stat --format %s "$out" "$1" | sed 'N;s|\n|*100/|' | bc)