Estimating the resolution of real images. - Ryuta Mizutani; Rino Saiga; Susumu Takekoshi; Chie Inomoto; Naoya Nakamura; Makoto Arai; Kenichi Oshima; Masanari Itokawa; Akihisa Takeuchi; Kentaro Uesugi; Yasuko Terada; Yoshio Suzuki (CoRR, 2017)