The "moral rights" in France and Germany, or the "Urheberrecht" in Germany and Austria and others in Europe prohibit even the creator to put things in the "public domain" to the full extend. There are pro and con debates about this, of course.

Even photos of works in the "public domain" might be protected again, e.g. read about the (in)famous Wikimedia Lawsuit from the German https://en.wikipedia.org/wiki/Reiss_Engelhorn_Museum