#!/bin/sh

Watermark=`zenity --file-selection --title="Select Watermark"`
Orientation=$(zenity  --list  --text "Watermark location?" --radiolist  --column "Pick" --column "Location" TRUE NorthEast FALSE North FALSE NorthWest FALSE East FALSE West FALSE SouthEast FALSE South FALSE SouthWest)
for file
do
name=`echo $file | cut -f1 -d.`
convert $Watermark -fill grey50 -colorize 40  miff:- | composite -dissolve 30 -gravity $Orientation - $file ${name}_watermarked.png
done