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This paper reviews the first challenge on efficient perceptual image enhancement with the focus on deploying deep learning models on smartphones. The challenge consisted of two tracks. In the first one, participants were solving the classical image super-resolution problem with a bicubic downscaling factor of 4. The second track was aimed at real-world photo enhancement, and the goal was to map low-quality photos from the iPhone 3GS device to the same photos captured with a DSLR camera. The target metric used in this challenge combined the runtime, PSNR scores and solutions' perceptual results measured in the user study. To ensure the efficiency of the submitted models, we additionally measured their runtime and memory requirements on Android smartphones. The proposed solutions significantly improved baseline results defining the state-of-the-art for image enhancement on smartphones. * A. Ignatov and R. Timofte ({andrey,radu.timofte}@vision.ee.ethz.ch, ETH Zurich) are the challenge organizers, while the other authors participated in the challenge. The Appendix contains the authors' teams and affiliations. PIRM 2018 Challenge webpage: http://ai-benchmark.org

Here we report an effective bottom-up solution-phase process for the preparation of nitrogen-doped porous carbon scaffolds (NPCSs), which can be employed as high-performance anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The as-obtained NPCSs show favorable features for electrochemical energy storage such as high specific surface area, appropriate pore size distribution (3.9 nm in average), large pore volume (1.36 cm g), nanosheet-like morphology, a certain degree of graphitization, enlarged interlayer distance (0.38 nm), high content of nitrogen (∼5.6 at%) and abundant electrochemically-active sites. Such a unique architecture provides efficient Li/Na reservoirs, and also possesses smooth electron transport pathways and electrolyte access. For LIBs, the anodes based on NPCSs deliver a high reversible capacity of 1275 mA h g after 250 cycles at 0.5 C (1 C = 372 mA g), and outstanding cycling stabilities with a capacity of 518 mA h g after 500 cycles at 5 C and 310 mA h g after 1500 cycles even at 10 C. For SIBs, the anodes based on NPCSs display a reversible capacity of 257 mA h g at 50 mA g, and superior long-term cycling performance with a capacity of 191 mA h g after 1000 cycles at 200 mA g.