§107 of the United States Code, Title 17 provides for fair use. Fair use allows for copyrighted works to be used for purposes such as criticism, comment, news reporting, teaching, scholarship or research without infringing so long as the four factors below are used to evaluate whether a use is fair or not.
The four fair use factors are:
The four factors must be individually assessed for each use and cannot be applied in a mathematical way (i.e. having three out of four factors in favor of fair use does not equate to "75% fair use" and is not automatically allowed).
For a use to be "transformative," it must "add something new, with a further purpose or different character, and...not substitute for the original use of the work."
A transformative work is not a derivative work - derivative works are the right of the copyright holder exclusively. Rather, a transformative work significantly changes the original to transform it into a new, copyrightable work.
You should ask yourself: has new expression or meaning been added to the original work and was value added to the original through the incorporation of new information, aesthetics, insights and understandings?