I need a public domain image for use on a cover for a new edition of a book. I found an image I love, but I don't know if it's in the public domain, or if somebody (the artist, presumably) still holds the copyright.
Specifically, the image is this:
Is there a way, short of hiring Columbo or Rockford, to find out if a particular image is copyrighted?
I'm not sure this is the best place to ask this, but I asked a similar question on the Patents StackExchange site, and was told my (copyright) question was definitely not about patents (true, but they seem related to me).