This uses feh's caption mode to enter/display image tags, which are then stored in the current directory as symlinks below .tags/. The script is written in zsh.

Script: imagetag.

Usage: imagetag [--untagged] [-- feh options] [ files ...]

By default, imagetag displays all files in the current directory. --untagged makes it only display images with no associated tags. If you specify files, only those are shown.

Note that imagetag always saves the tags in the current directory (in .tags/tagname/) and does not support recursion.