[ Thanks to Mike
Weber for this link. ]
“In this tutorial I will show you how to change the edges on the
picture using a GIMP feature called QuickMask. QuickMask is a
convenient way to modify your pictures. In this example we will not
use any of the more intense QuickMask features; instead we will
focus on simple procedures that will allow you to modify the
picture.“Open up a picture in GIMP. After the picture is open use a
selection tool. In this case I used a rectangle selection tool, to
select the part of the picture you will not want to edit. Remember
we are going to edit the edges of the picture…”