It can be easy to confuse attribution and citation for images, but these are two similar but distinct concepts.
Attribution gives credit to the author or creator of an image. When images are used for free under the terms of a Creative Commons license, it's important to provide attribution as requested. More information about how to properly attribute works is available from How to Give Attribution. Here's an example of a proper attribution:
"Cat paw" by cloudzilla is licensed under Creative Commons Attribution 2.0 Generic (CC BY 2.0).
Citations, on the other hand, identify the sources that helped you to develop or are referred to in your research by providing information on these sources in a standard format. Visit "Citing Images" for examples of how to cite images using common citation styles.
The use of images for educational purposes, such as teaching, is sometimes considered fair use. Each usage is different should be carefully considered. To learn more about making a fair use determination, visit the University of South Carolina's Intellectual Property Policy or the Library's Copyright Guide.
If you're publishing a work and need to use an image, you'll likely be required by the publisher to confirm that you have permission to use the image, that the image has been licensed for your intended use, or that the image is in the public domain. The Cornell Copyright and the Public Domain chart can help you determine if an item is in the public domain. You must also abide by any restrictions and agreements from the image owner or provider, even if the image is in the public domain, particularly when it is provided through a licensed database such as Artstor or a digitized collection.
If you determine that you need to seek permission to use a work, you'll need to identify and locate the copyright owner. Some commercial sites such as the Copyright Clearance Center can assist with these steps. Many electronic resources provide direct links to request permissions from within their site. Once you ask and have been granted permission, be sure to keep all relevant records.
Even if an image isn't protected by copyright, has been licensed to allow usage without attribution, or if you've obtained permission to use an image, it should be cited and/or identified if used in your research or teaching, depending on the style guide. All citation style guides include information for citing images. For more information and to access style guides, visit the Citation Formats Guide. Examples of citations are available below.