Scope of Database
Does the database focus on a particular subject or discipline? Is the database focused on current or historical images? Are the images taken by professionals or amateurs? You will use different image sources for different types of images.
Image Quality
You may be looking for high-quality images for use in your multimedia design projects. Images found on the web tend to be low-resolution, for speed of loading and ease of sharing. Try specialized image databases for higher-quality images.
Copyright Issues
Do not assume that just because an image is available on the web, you're permitted to use it in any way you wish. Creators of images (photographers, artists, illustrators, etc.) own copyright just as authors of books and articles do.
Some creators of images choose to make them available via what is known as a "Creative Commons License". This means that the individual has chosen to release some of their rights as the copyright holder to you, the user. They may specify, for example, that you may use the image for non-profit purposes as long as you credit the source.
Even without a creative commons license, for students' purposes (course projects) you are generally permitted to use images under a law known as "fair use," meaning that you are using them for educational purposes. However, there are a few rules of thumb for legal and ethical use of images:
DO provide a caption for the image, and an entry in your bibliography — you must cite an image just as you would cite a book or journal article
DON'T use more than 5 images by any one artist/photographer, and not more than 10% or 15 images from any one published collective work
DON'T disseminate your work by placing it on the web, or by publishing it (earning a profit from it), without first approaching the creators of the images to obtain permission. You will need to be even more aware of this when you become a practicing professionals, because your work will no longer fall under "fair use" law.
JSTOR Image Library is a cross-disciplinary collection of images supporting education and research. JSTOR Image Library images have been rights-cleared for use in education and research, including classroom instruction and other noncommercial educational and scholarly activities. Community collections include images and primary source materials contributed by Cal Poly and other member organizations; access or rights may be restricted.
Here is an example of a caption and bibliography entry for an image retrieved from an online database (in this case, the Library of Congress American Memory Project)
Giving proper credit for images has two parts: a caption with the image itself, and an entry in your bibliography. Where the image appears, write a descriptive caption indicating the source of the image. Then create an entry in your bibliography. While most citation styles do not give a rigid format for citing images, you can construct informative citations based on some or all of the following elements:
Concentrate on creating the best citation you can given the information you can locate. The intent is not to frustrate you with intricate rules, but to give you guidelines so that you can provide your reader with enough information that they can track down the original image if they so choose.