Four factors are used as a guideline when considering whether the use of a work is "fair use."
The four factors are:
Simply providing an acknowledgement of a work does not make it permissible to use that work or a portion of it. One example is using an image from a book or magazine and including the name of the photographer or artist. Acknowledgment of the source material does not protect against an infringement claim. Risk of infringement exists even when you make use of personal photographs of textual or visual works produced by others. If you have any doubt about the right to use, the best approach is to seek the permission of the copyright owner.
Transformativeness is defined by whether 1) value is added to the original by creating new information, new aesthetics, new insights and understandings, and 2) whether the material taken from the original work has been transformed by adding new expression or meaning. Parody is a common example of transformative use.
The University of Minnesota has a helpful discussion of Fair Use that includes example scenarios.