On Balancing Energy Consumption, Rendering Speed, and Image Quality on Mobile Devices

2012 ◽  
pp. 231-250
Author(s):  
Fan Wu ◽  
Emmanuel Agu ◽  
Clifford Lindsay ◽  
Chung-han Chen
Keyword(s):  
Energy Consumption ◽  
Image Quality ◽  
Mobile Devices ◽  
Time Frame ◽  
Operating Conditions ◽  
Mobile Graphics ◽  
Balancing Energy ◽  
Interactive Frame ◽  
Battery Energy ◽  
Predict Model

Mobile games and graphics are popular because un-tethered computing is convenient and ubiquitous entertainment is compelling. However, rendering graphics on mobile devices faces challenges due to limited system resources, such as battery energy, and low memory and disk space. Real time frame rates, low energy consumption and high image quality are all desirable attributes of interactive mobile graphics; however, achieving these objectives is conflicting. For instance, increasing mesh resolutions improves rendered image quality but consumes more battery energy. Therefore, the authors propose a mobile graphics heuristic to minimize energy consumption while maintaining acceptable image quality and interactive frame rates. Over the lifetime of a mobile graphics application, scene complexity, animation paths, user interactivity and other elements all change its CPU and resource demands. In this regard, a heuristic that dynamically changes scene mesh LoDs and amount of CPU timeslices allotted to the mobile graphics application is presented to select optimal operating conditions that balance rendering speed, energy conservation and image quality. Additionally, a workload predict model is proposed so that the heuristic can monitor both application workload and the availability of resources of mobile devices periodically, while adaptively determining how much resources will be allocated to applications.

UbiWave

2010 ◽  
pp. 124-179
Author(s):  
Fan Wu ◽  
Emmanuel Agu ◽  
Clifford Lindsay ◽  
Chung-han Chen
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Mobile Device ◽  
Unequal Error Protection ◽  
New Class ◽  
Mobile Access ◽  
Mobile Graphics ◽  
Error Metric ◽  
Battery Energy ◽  
Visual Realism

Advances in ubiquitous displays and wireless communications have fueled the emergence of exciting mobile graphics applications including 3D virtual product catalogs, 3D maps, security monitoring systems and mobile games. Current trends that use cameras to capture geometry, material re?ectance and other graphics elements mean that very high resolution inputs are accessible to render extremely photorealistic scenes. However, captured graphics content can be many gigabytes in size, and must be simpli?ed before they can be used on small mobile devices, which have limited resources, such as memory, screen size and battery energy. Scaling and converting graphics content to a suitable rendering format involves running several software tools, and selecting the best resolution for target mobile device is often done by trial and error, which all takes time. Wireless errors can also affect transmitted content and aggressive compression is needed for low-bandwidth wireless networks. Most rendering algorithms are currently optimized for visual realism and speed, but are not resource or energy ef?cient on a mobile device. This chapter focuses on the improvement of rendering performance by reducing the impacts of these problems with UbiWave, an end-to-end framework to enable real time mobile access to high resolution graphics using wavelets. The framework tackles the issues including simpli?cation, transmission, and resource ef?cient rendering of graphics content on mobile device based on wavelets by utilizing 1) a Perceptual Error Metric (PoI) for automatically computing the best resolution of graphics content for a given mobile display to eliminate guesswork and save resources, 2) Unequal Error Protection (UEP) to improve the resilience to wireless errors, 3) an Energy-ef?cient Adaptive Real-time Rendering (EARR) heuristic to balance energy consumption, rendering speed and image quality and 4) an Energy-ef?cient Streaming Technique. The results facilitate a new class of mobile graphics application which can gracefully adapt the lowest acceptable rendering resolution to the wireless network conditions and the availability of resources and battery energy on mobile device adaptively.

Imperceptible Simplification on Mobile Displays

2012 ◽  
Vol 3 (1) ◽  
pp. 37-54 ◽  
Author(s):  
Fan Wu ◽  
Emmanuel Agu ◽  
Clifford Lindsay ◽  
Chung-han Chen
Keyword(s):  
Mobile Devices ◽  
Pareto Distribution ◽  
Level Of Detail ◽  
Direct Access ◽  
Mobile Graphics ◽  
Knee Point ◽  
Wide Range ◽  
System Resources ◽  
Battery Energy ◽  
Visual Realism

Graphics on mobile devices is becoming popular because untethered computing is convenient and makes workers more productive. Mobile displays have a wide range of resolutions that affect the scene Level-of-Detail (LoD) that users can perceive: smaller displays show less detail, therefore lower resolution meshes and textures are acceptable. Mobile devices frequently have limited battery energy, low memory and disk space. To minimize wasting limited system resources, the authors render mobile graphics scenes at the lowest LoD at which users do not perceive distortion due to simplification. This is called LoD the Point of Imperceptibility (PoI). Increasing the mesh or texture resolution beyond the PoI wastes valuable system resources without increasing perceivable visual realism. The authors propose a perceptual metric that can easily be evaluated to identify the LoD corresponding to a target mobile display’s PoI and accounts for object geometry, lighting and shading. Previous work did not directly compute changes in the PoI due to target screen resolution. The perceptual metric generates a screen-dependent Pareto distribution with a knee point that corresponds to the PoI. We employ wavelets for simplification, which gives direct access to the mesh undulation frequency that we then use to parameterize the CSF curve.

Challenges with high quality mobile graphics

2013 ◽  
Author(s):  
Sam Martin ◽  
Marius Bjørge ◽  
Sandeep Kakarlapudi ◽  
Jan-Harald Fredriksen
Keyword(s):  
High Quality ◽  
Mobile Graphics
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