How do I cite an image from wikicommons in my thesis?
Even if its in the public domain its always good to cite where you get your information from, be that data, images, or whatever, even if its public domain
When I use images that are governed by a license (including public domain, and &quot;fair use&quot;) I identify

the source,
the original author/photographer/painter/etc, and
the specific license that governs its reuse.

Using thorough and accurate citations ensures that you've done everything that needed to give proper credit where credit is due.
It also allows the reader to verify that what you cite is really at the source you give, and is licensed for the use to which you put it.
It doesn't hurt to include in the source, links to the actual source, and to the license (say as defined by Wikipedia, or the specific source you used.