There are programs that do this, but two easy ways are:
If you are on a computer, just use the "Snipping Tool". Essentially get the picture how you want it to look on your screen (Size, frame, etc.), then use the snipping tool to crop it / save as a new picture. Search for "Snipping Tool", then it is just as easy as drawing a box around whatever you want to "snip" on your screen.
If you can get the picture on a phone, you can "screenshot" your screen. Which will save them as a lower quality. On an iphone, get the picture how you want it to look on your screen, then press the "home" and "power" buttons at the same time. This will screenshot your screen and place that picture in your photos. On an android, you do the same thing, but press the "power" and "volume down" button at the same time.
Edited by Fowl Play, 14 November 2017 - 10:00 AM.