SHF: Small: Turning Visual Noise into Hardware Efficiency: Viewer-Aware Energy-Quality Adaptive Mobile Video Storage

智能手机等移动设备正越来越多地被用于观看视频，因为它们可以随时随地方便地用于这一目的，例如在地铁或火车上通勤，坐在候车室里，或者在家休息。由于数据量大，计算密集，视频处理需要频繁的内存访问，这会消耗大量电力，限制电池寿命，并阻碍移动用户。一方面，内存设计者专注于硬件级的功耗优化技术，而没有考虑硬件性能如何影响观众的实际体验。另一方面，人类视觉系统在检测图像质量的细微降级方面的能力有限；例如，在高环境照度的条件下，例如室外阳光直射，移动设备屏幕上的面纱亮度(即眩光)可以有效地掩盖图像中的缺陷，从而在这些情况下，视频可以被呈现为低于全质量，而观看者无法检测到任何差异。由于过于悲观的设计余量，硬件设计和观众体验之间的这种隔离显著增加了硬件实施开销。该项目将观众感知和硬件适配相结合，在不降低用户感知的视频质量的情况下实现功率优化。该项目的结果将影响硬件设计和人类视觉的基础研究，并提供来自人类受试者的关键观众感知数据，这些数据可用于设计更好的视频渲染，以延长移动设备的电池寿命。该项目将直接让本科生和研究生，包括女性和美洲原住民，参与跨学科研究。开发观众感知的移动视频存储器解决方案已被证明是一个非常具有挑战性的问题，因为(I)复杂的现有观众体验模型；(Ii)没有运行时适配的存储器模块；以及(Iii)硬件设计者的观众体验分析的难度。该项目通过以下方式解决这个问题：(I)关注影响观众体验的最具影响力的观看情境因素--环境亮度；(Ii)提出自适应硬件设计的新方法；以及(Iii)整合从心理学到集成电路设计和嵌入式系统的研究人员的独特专业知识。具体地说，该项目将(I)通过实验和数学方法将观众体验、环境照度和内存性能联系起来；(Ii)开发能量质量自适应硬件，该硬件可以根据环境亮度调整内存使用，从而在不影响观众体验的情况下减少功耗；以及(Iii)设计移动视频系统，以全面评估所开发方法的有效性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Mobile devices, such as smart phones, are being increasingly utilized for watching videos, since they can be conveniently used for this purpose anywhere anytime, such as commuting on a subway or train, sitting in a waiting room, or lounging at home. Due to the large data size and intensive computation, video processing requires frequent memory access that consumes a large amount of power, limiting battery life and frustrating mobile users. On one hand, memory designers are focusing on hardware-level power-optimization techniques without considering how hardware performance influences viewers' actual experience. On the other hand, the human visual system is limited in its ability to detect subtle degradations in image quality; for example, under conditions of high ambient illumination, such as outdoors in direct sunlight, the veiling luminance (i.e., glare) on the screen of a mobile device can effectively mask imperfections in the image, so that under these circumstances a video can be rendered in lower than full quality without the viewer being able to detect any difference. This isolation between hardware design and viewer experience significantly increases hardware implementation overhead due to overly pessimistic design margins. This project integrates viewer-awareness and hardware adaptation to achieve power optimization without degrading video quality, as perceived by users. The results of this project will impact both basic research on hardware design and human vision, and provide critical viewer awareness data from human subjects, which can be used to engineer better video rendering for increased battery life on mobile devices. The project will directly involve undergraduate and graduate students, including females and Native Americans, in interdisciplinary research. Developing a viewer-aware mobile video-memory solution has proven to be a very challenging problem due to (i) complex existing viewer-experience models; (ii) memory modules without runtime adaptation; and (iii) the difficulty of viewer-experience analysis for hardware designers. This project addresses the problem by (i) focusing on the most influential viewing-context factor impacting viewer experience - ambient luminance; (ii) proposing novel methodologies for adaptive hardware design; and (iii) integrating a unique combination of expertise from the investigators, ranging from psychology to Integrated Circuit design and embedded systems. Specifically, this project will (i) experimentally and mathematically connect viewer experience, ambient illuminance, and memory performance; (ii) develop energy-quality adaptive hardware that can adjust memory usage based on ambient luminance so as to reduce power usage without impacting viewer experience; and (iii) design a mobile video system to fully evaluate the effectiveness of the developed methodologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.