how to make a rectangle image a square image using GIMP

I like reusing profile pictures from the web in my Google Mail Contacts aka address book. On Xing or LinkedIn these pictures not necessarily are square, but on Google Mail Contacts you have to choose a sub-square. So maybe you want to resize the picture appropriately, so you don’t cut it, where you don’t want… Continue reading how to make a rectangle image a square image using GIMP