Fair use allows certain uses of copyrighted works without obtaining permission from the copyright owner. Fair use allows copying of copyrighted material in an educational setting, such as a teacher or a student using images in the classroom. Fair use is flexible concept and can be open to interpretation in certain cases. A digital copy is considered on the same footing as a print copy for purposes of fair use.
In some cases, fair use rights can be subject to restrictions (license agreement or donor agreement).
There are 4 factors to consider in fair use. These are only guidelines.
1. The purpose and character of your use
It is fair use to use an image for teaching in person and online and for research, scholarship, and study. It is fair use to display images to convey a scholarly argument or to convey information.
The transformative factor: if you use images and create a new work by creating new aesthetics, new insights, and understandings, the law has considered it fair use. However, determining what is transformative--and the degree of transformation—can be challenging.
2. The nature of the copyrighted work
Many images are creative in nature but it is still fair use to use them in an educational setting.
3. The amount and substantiality of the portion taken
Users typically need to use entire images to make their point but it is still fair use to use them in an educational setting.
4. The effect of the use upon the potential market
Users displaying images usually do not decrease the value of the images.