Extension:ImageTagging

ImageTagging extension lets a user select regions of an embedded image and associate an article with that region. Images can be viewed by tag. Tagging is shown in a new tag log.

Usage
Go to a image page on your wiki. You should see "Tag this imageNew!" next to "Links" in the header. Clicking on the "Tag this image" pops out the usage info. Now you can click on any part on the picture (e.g. a person) to tag it. You can use interwiki links in the tag, too. It is useful if you would like to link to an article about Jimmy Wales that doesn't exist locally but exists on Wikipedia or another wiki in the interwiki map.

After you are done, click "Done tagging" and the ImageTagging menu is dismissed. Below the file size & MIME type info, you can see all existing tags that the image has. Clicking on "images" allows to see more pictures tagged with the same tag and "remove tag" allows to remove an existing tag. Image tag additions and removal are logged to image tagging log (Special:Log/tag) which is a bit buggy at the moment.

You can view all tagged images on Special:TaggedImages.