You start with an image, and then you photoshop something in. Here's the starter image! 

[img]https://geographical.co.uk/media/k2/items/cache/f1643f36708fadabd1f1bf38a425687f_XL.jpg[/img]

[url]https://www.gimp.org/downloads/[/url]
I find that Gimp is a GREAT free program for this.