Images, like all sources of intellectual property, are subject to the laws of copyright. If an image is copyrighted, you must determine if your use of the image falls under the Fair Use guidelines (see below). Fair use allows use of copyrighted materials on a limited basis for specific purposes without the permission of the copyright holder. If your use of the image is not considered Fair Use, you will either need to pay for use of the image, or find a different image that is copyright-free.
To help determine whether use of an image is fair use, consider the following four factors of Fair Use:
Remember, if you're ever unsure, a librarian is always here to help!