Adding WaterMark

To add WaterMark to an image we can use the tool which ships with Ubuntu

$composite -dissolve 10% -gravity south input_file.jpeg watermark.jpeg output.jpeg
$composite -dissolve 10% -gravity south watermark1.jpeg IPTables1.jpeg output.jpeg

Here 10% is the brightness of the watermark1.jpge
-gravity south will pull your image to the bottom