Preserving audio and visual images, both still and moving, can be a big challenge. Fortunately considerable research has been carried out in this area and there have now been many major programmes looking at preservation of these type of objects including the JISC Repositories and Preservation Programme.
If you need to preserve image, video or audio files your first stop should be JISC Digital Media which provides advice and guidance on the creation and use of digital media collections in learning, teaching and research. It has a category of ‘digital preservation’ which contains lots of resources for different formats. It also provides a list of links to digital media and digital preservation organisations and, if you are based in an HE/FE institution, they will seek to give you specific advice on your problem.
The Library of Congress has a useful Sustainability of Digital Formats Web site which looks at formats for still images, sound and moving images.
There are several significant properties testing reports which look at the properties that will need to be captured when preserving.