Hi emerlo,
Currently, cropnote does not store the image source in the plugin. It saves a hash of the image src attribute which is used to create the IMG ID that you can see in the Image Notes table. This behavior is inherited from the plugin I used as a basis for Cropnote (Demon Image Annotation). I don’t know what led to that design decision, and I didn’t consider changing it when I wrote Cropnote – I just left it alone because it was working!
I think in order to get the feature you want, you would need to add the image source as a parameter in the AJAX request when saving image notes, and then write the source to the WP DB from within the AJAX handler.
For notes that have already been saved, or if you didn’t want to do that, you could write a php function that iterated through each page/post in the blog and calculated the image id the same way, and compared those ids with the ids in the cropnote database table.
I hope this helps give you an idea on where to start.
Jeff
