sticker.sh

#!/bin/bash

if [ -z "$1" ]
  then
    echo "No input file supplied"
fi

convert $1 \
    -trim -resize 512x512 \
    \( -clone 0 -background white -shadow 100x2+0+0 -channel A -level 0,5% +channel \) \
    -reverse -background none -layers merge +repage \
    \( -clone 0 -background black -shadow 25x5+5+5 \) \
    -reverse -background none -layers merge +repage \
    -resize 512x512 -gravity center -extent 512x512 \
    $1.sticker.png