We can use GANs to generate original images, but if I train my GAN using CC-BY-ND am I creating a derivative work? If I train with CC-BY-NC images (or even copyrighted images), do I have rights to use the output commercially?
Note that here I am referring to not the model parameters, but specifically the output images; if I generate an interesting image (like the dog/tennis ball hybrid on the linked site), can I legally put it up for sale on a stock photo site, for example?
Additional info: ImageNet, one of the popular training sets, has this to say about usage issues.
The images in their original resolutions may be subject to copyright, so we do not make them publicly available on our server.
Researcher shall use the Database only for non-commercial research and educational purposes.