Giving Credit for use of Images or Other Materials
If you use images or other media on any of your website, you should credit your sources just as you would any quotations or paraphrases that you use in a paper.
The use of images in a student project done for a class probably represents fair use, though if you are asked to remove a graphic from one of your sites, you should do so promptly.
Fair use, however, is not an excuse of plagiarism. Always give credit and appropriate citations for any materials you use in a website.
There are no established conventions for giving credit, but here is an easy option your can use:
Give credit on the page.
Often an easy solution. If you follow this approach, keep the reference small and out of the way. Crediting on the page works best when you have a few very important images in your site. You can give your credit below the image as in the example, or you can credit images at the bottom of the page.
Image source: http://www.ilstu.edu