Images contain objects with deformable boundaries, such as the contours of a human face, yet attention operators act on square windows. This mixes features from perceptually unrelated regions, which can degrade the quality of a denoiser. One can exclude pixels using an estimate of perceptual groupings, such as superpixels, but the naive use of superpixels can be theoretically and empirically worse than standard attention. Using superpixel probabilities rather than superpixel assignments, this paper proposes soft superpixel neighborhood attention (SNA), which interpolates between the existing neighborhood attention and the naive superpixel neighborhood attention. This paper presents theoretical results showing SNA is the optimal denoiser under a latent superpixel model. SNA outperforms alternative local attention modules on image denoising, and we compare the superpixels learned from denoising with those learned with supervision.

Reducing power consumption has been one of the most important goals since the creation of electronic systems. Energy efficiency is increasingly important as battery-powered systems (such as smartphones, drones, and body cameras) are widely used. It is desirable using the on-board computers to recognize objects in the images captured by these cameras. The Low-Power Image Recognition Challenge (LPIRC) is an annual competition started in 2015. The special session includes presentations given by the winners of the first three years of LPIRC. This paper explains the rules of the competition and the rationale, summarizes the teams' scores, and describes the lessons learned in the first three years. The paper suggests possible improvements of future challenges.

Significant progress has been made in recent years using computer programs recognizing objects in images. Meanwhile, many cameras are embedded in battery-powered systems (such as mobile phones, wearable devices, and drones) and energy efficiency is essential. Even though many research papers have been published on the topics related to low power and image recognition, there does not exist a common metric for comparing different solutions in terms of (1) energy efficiency and (2) accuracy in recognition. Low-Power Image Recognition Challenge (LPIRC) is, to our knowledge, the only on-site competition that considers both energy consumption and recognition accuracy. LPIRC was held as one-day workshops in the Design Automation Conference in 2015 and 2016. Each participating team brought their own system to the workshops. The referee system of LPIRC includes (1) an intranet, (2) a power meter, and (3) an HTTP server that provided the images and accepted the answers from the contestants' systems. The scores were the ratio of recognition accuracy and the energy consumption. The winner of 2016 was able to analyze 7,347 images and achieve 9.44% normalized mAP (mean average precision) with average power consumption of 4.7 W. Another team analyzed 1,020 images and achieved 25.7% normalized mAP.

The Internet of Things (IoT) is the internetworking of a variety of devices, including sensors. Among all sensors, visual sensors (i.e. cameras) are special because they can provide rich and versatile information. The world already has more than one billion cameras on mobile phones. We define the internet-working of visual sensors as the Internet of Video Things. This article estimates the number of cameras the world will see in 2030 and the implications of a large number of cameras. Transmitting, storing, and analyzing the data from cameras could impose significant challenges to existing technological infrastructures. This paper surveys recent progress in relevant technologies and suggests directions for future research.