Forum Moderators: mack
If it's just to an image itself which also appears on a page that has a URL, then definitely keep it off your site map in any case. If you're talking about gallery pages that have one image and some surrounding text, that's another story.
If it's for users, 4000 items is way way way too many. You need some other type of navigation.
If it's for search engines, I think it depends on what else is on those pages. If the image is surrounded by descriptive text and has a descriptive name (like 'vanessa-fox-nude.jpg' rather than 'DSC0000324.jpg') than it may be worth it. If you have an image that appears in isolation without any text content and without a descriptve name, there's no point in telling a search engine about it.
the site is about greece, sightseeing, toursit info and accommodations.
each area has a gallery, images with distinct names, not ids.
each text has 1-2 images also (text between 400 chars and 2000 chars).
I thought of making the sitemap for images myself, but when i saw the volume of images - let's just say i will use an automatic script for the job.
I get a lot of traffic from google image search and, generally, it's just a bandwidth leach. Get the pages with the images in the engines and don't worry about the raw images (I actually try to exclude them from the crawl with robots.txt).