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

DIR="$1"
HASH="$2"
EXT="$3"

cd "$DIR"
for size in thumb:200 medium:800 large:1600; do
    name="${size%%:*}"; px="${size##*:}"
    magick "${HASH}-original.${EXT}" -resize "${px}x${px}>" "${HASH}-${name}.jpg"
done