This searchable repository of over 1.6 million high quality digital images offers tools for viewing, sharing, and saving visual materials. Although its strengths are visual art and architecture, Artstor includes images that are useful in both the humanities and the sciences.
Library of high-quality photographs with Creative Commons licenses. Has few details and requires significant evaluation as this is a crowd-sourced resource (anyone can contribute).
You can also look for images in print or electronic books that can be reproduced for your presentation. Also, many museums and cultural organizations offer photographs of their collections, such as the Kyoto National Museum. Even outside of Asia, large museums have Asian collections such as the Met's John C. Weber Collection or the Louvre's collection of Islamic art. Many major museums will have their collections in ARTstor, but you may still stumble on different items going to the museum websites as you find through an ARTstor search.
Please come ask for help if you are struggling to find images for your presentation.