#!/bin/bash

if [[ $# -lt 2 ]]; then
	echo "Usage: $0 SOURCE PREFIX" >&2
	exit 1
fi

SOURCE=$1
PREFIX=$2
SUFFIX=.png
SIZES=(16x16 32x32 96x96)

for size in "${SIZES[@]}"; do
	target="${PREFIX}${size}${SUFFIX}"
	convert -background none "$SOURCE" -resize "$size" "$target"
	optipng "$target"
done