Marjorie Hlava has an article in the August 2005 issue of the Special Libraries Association's Information Outlook entitled "Automatic Indexing: Comparing Rule-based and Statistics-based Indexing Systems." Although this may not be pertinent to a digital imaging project, your colleagues may think that you know about automatic indexing just "because." This article compares these two types of indexing systems AND gives some cost information (something that can be very useful and not always readily available).
If you don't receive Information Outlook, you might find the article through one of the online databases. Also many libraries do receive Information Outlook for their librarians, so you might check to see if the issue is available there (perhaps not in the catalogue but in their lounge).