Attributing the creator is necessary anytime you use an image. Whether you had to obtain permission or it was freely available to use, it is necessary to give credit to the creator or copyright holder. Make sure to read the usage rights statements on websites to understand if there is specific wording that needs to be used.
There are potentially three places you will need to cite.
Consult the style guide examples in this guide for examples.
Web Only Image
In text
The aurora borealis (see fig.1) is a natural multicolor light display produced by solar wind particles seem in high latitude regions.
Image Caption
Fig. 1. “Aurora Over Calgary and Spokane.” NASA’s Marshall Space Flight Center.
Works Cited Example
Last-name, First-name or Username. “Title of Image.” Medium of work. Date of resource creation. Name of site. URL
Works Cited
NASA’s Marshall Space Flight Center. “Aurora Over Calgary and Spokane.” Photograph. 19 Feb. 2012. Flickr. https://www.flickr.com/photos/nasamarshall/14743833915/in/photolist-osS1a2
The Writing Lab at Purdue University does a superb job of helping to guide students in the use of the writing style guides.
Don't forget to schedule an appointment with the WCU writing center! They're able to help you online: