Prevent blog photos appearing in activity river


I'm using Elgg 3.14, Tidypics 3.3.1 and Blog 3.0. Adding an image to a blog post also adds that image to the activity river. I know I can switch off all uploaded photos appearing in the activity river, but I was wondering if there's a way to prevent only photos that are embedded in pages and blogs from appearing in the river?

One workaround is to sign in as admin and delete the photos from the river, however, this solution would mean making all the users admins.

Thanks in advance.