^http://imgur\.com/(?:download/)?([\w^_]{7})$
http://imgur.com/download/\1
^http://i\.imgur\.com/([\w^_]{7})(?:[sbtmlh])\.(?:gifv?|jpg|png)$
^(https?://.+/).+\.(?:gif|jfif|jpe?g|png)(?:(?:\?|&).*)?$
\0
\1