If you use the Tools | Export to HTML.... function, you should be able to extract cover images.

(If you only want the cover images and not all the metadata, you'll have to customize one of the templates using DaxEdit.)

However, if you've imported covers that exceed the maximum cover size set in OrangeCD (default is 32KB, I think), and you've checked 'Store covers in external files.....', a copy of your images will be stored in a sub folder called <your music collection>_covers.