Resize images with ImageMagick for srcset usage for Responsive Designs/Images

convert-resize-image.sh

#!/usr/bin/env bash

if [ ! $# == 1 ]; then
    echo "Missing input param, file name."
    exit 1;
fi

sizes=(1280 1024 640 320)
# make sizes readonly
declare -r sizes

for i in "${sizes[@]}"; do
   convert $1 -resize "$i"x $i-$1
done