The International Journal of Virtual Reality, 2006, 5(3):9-15 Multiresolution Graphics on Ubiquitous

Abstract — Large meshes or images cannot be rendered at full resolution on mobile devices such as cell phones, PDAs and laptops since these devices have limited storage, CPU, memory, display, and battery power. Wavelet-based multiresolution analysis can represent meshes and graphics input at multiple Levels of Detail (LODs). We propose UbiWave, a wavelet-based framework for scalable transmission of large meshes and graphics content to heterogeneous ubiquitous computing devices. In UbiWave, a base representation and different levels of wavelet coefficients are pre-generated at the server. An optimal LOD level is transmitted to each mobile client based on its spacification and wireless channel conditions, where the corresponding LOD is reconstructed. To save scarce resources on mobile devices, we render graphics content at the lowest LOD that does not show visual artifacts, called the point of indiscernability (PoI). By rendering content at the PoI instead of the highest resolution, we are able save 61 % decode time and 45 % energy usage on the client. Index Terms — multiresolution rendering, ubiquitous graphics, wavelets