Image Credit Overlay

Hi all,

Is there a plugin or way of adding the image credit as an overlay, or some other more aesthetically pleasing way than ‘Source: …’ below the image.

http://www.bbc.co.uk/news/uk-england-london-36587103
http://www.gaystarnews.com/article/gay-65-happiest-sex-lives/#gs.zCxi3WE

The above provide examples of what I am trying to achieve.

Regards,
Joseph