• Artstor
• Britannica ImageQuest
• Database of Japanese Art in Overseas Collections
• Database of Ukiyo-e held at the Library of Congress
• Digital Collections
• Geheugen van Nederland
• Southeast Asian & Caribbean Images (KITLV)

CC Search: handy website for searching free to use images.

A selection out of the many online image resources available:

• Bildindex der Kunst und Architectur
• Europeana
• Library of Congress
• Rijksstudio
• The J. Paul Getty Trust
• The Commons Flickr (The British Library)
• NASA
• National Gallery of Art
• EveryPixel
• Unsplash for education
• Skitterphoto
• Pexels

Copyright is the exclusive right of the creator of an original work (image, photo, paining, text, etc.) to publish and reproduce this work. If you want to use a image, picture of movie you have found online or in a printed publication than you are required to ask for permission from the creator. Exceptions to this rule are citations, works in the public domain and images from databases the library has a subscription on. 

Citations

Reasoning it is difficult to review a work without using parts from that work copy right law makes an exeception for citations. You don't have to ask for permission when an image is used for illustrating an idea or text and only forms a small part of a whole. However, when an image is only used to decorate an essay or presentation you are required to ask permission. And of course, be careful to always attribute the source and the creator of a work.

Licensed works

The university library has taken out a subscription to a large number of databases, see Image Databases above. The images in these databases are free to use provided they are used for educational purposes (such as a paper or presentation). If the paper or presentation can be viewed online by everyone (as may be the case in the thesis repository), then permission must be requested in advance. Look for specific provisions in the database itself.

Works in the public domain

If the creator of a work has died more than 70 years before, a work is in the public domain and is completely copyright-free. Some works are already in the public domain at the time of production. A creator can indicate via a Creative Commons license if he or she wants to give other people the right to share, use, and build upon a work he/she has created (see below). A CC-license makes it easy to find out if you need permission. 

Linking or embedding

Linking or embedding of materials is always allowed provided the work is free and legally accessible. Embedding is the integration of images into social media posts or other web media. Embedded content appears as part of a post, but the image itself remains on the website on which it has always been displayed. Many social media offer an embed code (often under the name "Sharing"). To make an embed code right click on the image and choose 'Copy'.  Paste the url between the "image tags": <img src="URL"/>.

It is important to always mention the creator and source of a work, both in the text as below the image itself and in your bibliography.  How to cite an image depends on the citation style you're using. Check for examples one of the books below or use an citation manager, such as Endnote, Mendeley of Zotero.

• Doing Honest Work in College: how to prepare citations, avoid plagiarism, and achieve academic success (Charles Lipson, The University of Chicago Press 2018)
• Cite them Right: The Essential Referencing Guide (Richard Pears, Red Globe Press 2019)
• The Complete Guide to Referencing and Avoiding Plagiarism (Colin Neville, Open University Press 2010)