Keep the ALT tags, but lose the meta tags. Ensure all images have a good ALT tag applied to them so that search engines can recognize them when indexing. For example, if you have an image of the Mona Lisa, name it “Mona Lisa”… Or, at least something that properly describes the image. Don’t just use “graphic” or – worst yet – nothing at all!
As for meta tags, almost all have gone “the way of the dodo bird” so to speak. The exception to this is the “description” meta tag, which many search engines use to describe your site on their results listings.