Thread:NoWayThisUsernameIsAlreadyOwnedBySomeone/@comment-24335865-20150621120444/@comment-26143371-20151016203555

With ImageMagick and the following command: mogrify -flip -rotate 180 filename.png

The same thing could be done with GIMP or any of the professional photo-editing softwares. But for me the command line was simply faster.