NTIRE 2019 challenge on real image super-resolution: Methods and results

Jianrui Cai, Hong Kong Polytechnic University
Shuhang Gu, ETH Zürich
Radu Timofte, ETH Zürich
Lei Zhang, Hong Kong Polytechnic University
Xiao Liu, Baidu, Inc.
Yukang Ding, Hong Kong Polytechnic University
Dongliang He, Hong Kong Polytechnic University
Chao Li, Hong Kong Polytechnic University


This paper reviewed the 3rd NTIRE challenge on single-image super-resolution (restoration of rich details in a low-resolution image) with a focus on proposed solutions and results. The challenge had 1 track, which was aimed at the real-world single image super-resolution problem with an unknown scaling factor. Participants were mapping low-resolution images captured by a DSLR camera with a shorter focal length to their high-resolution images captured at a longer focal length. With this challenge, we introduced a novel real-world super-resolution dataset (RealSR). The track had 403 registered participants, and 36 teams competed in the final testing phase. They gauge the state-of-the-art in real-world single image super-resolution.