As with text, images are also protected by copyright law. You must therefore have permission to make use of them.
The licensee may have given permission for free use of the image either by disclosing this specifically or through a Creative Commons license. You can read more about Creative Commons.
If the photographer has been dead for more than 70 years, the image is no longer protected by copyright and you are free to use it, so long as you indicate the name of the photographer.
Images in this context should be understood broadly as art, drawings, photographs, illustrations, figures and graphs.
If you make use of images in assignments related to your study, then you are, as a student, bound by the Framework Agreement that exists between Aarhus University and VISDA (Copydan BilledKunst). Download the Framework Agreement.
The agreement allows you to make use of images found on the Internet in essays or PowerPoint presentations, as long as the material is only placed on Brightspace and similar secure intranets and not published elsewhere. Always remember to include the source, whether you use the image in an assignment, PowerPoint or similar.
If you upload an assignment to a thesis/dissertation repository, social media, your website, or similar, in such a way that the assignment becomes publicly available then you will no longer be covered by Aarhus University and Copydan BilledKunst’s Framework Agreement.
You must therefore either remove the images from the assignment or contact the copyright holders and ask for permission to use the images.
Always remember to include the source, whether you use the image in an assignment, PowerPoint or similar.
If you take any images yourself that include people, which you then go on to use in an assignment, you must remember to get permission from the persons who appear in the photo. It is always best to get such consent in writing.