Certainly you have seen a fully cut photograph multiple times which was decorated in round closed corners.
This effect is not difficult to obtain, even if you cut as little as used in equipment like my Pic.
Cut My Image is a free online application that allows you to cut and rotate the corner of any photo in three easy steps.
The only thing you want to do is select the cut image, indicate the angle you want to keep inside the cut area and adjust the angle of the round angle. You can activate preview to see changes before changing changes.
When you decide to implement the changes, you can choose to save your hard disk image or send it an email.