Since lossy compression discards information every time the file is saved, it stands to reason that there will be a point where too much information will be lost. This is why people say you should always work with an uncompressed original file, but just how badly does repeated saving mangle an image?

To see how repeated loading and saving can affect an image, a simple program was created to repeatedly save an image 2000 times in quick succession. Each iteration worked with the output of the previous call and used a quality setting of 75%. In theory, this should compound the artifacting caused by lossy compression and heavily distort the image.

Surprisingly, the damage done to the butterfly and cat photographs wasn't as obvious as expected. The Cartoon Train image, however, was clearly wrecked.

This suggests that while it's usually a good idea to work from a clean source file, it should be possible to make multiple edits can be made to a photograph before serious problems emerge.