A Sampling-Agnostic Software Framework for Converting Between Texture Map Representations of Virtual Environments

Published

May 18, 2017

Author(s)

Vinay Sriram, Wesley N. Griffin

Abstract

We have developed a utility to both stitch cube maps into other types of texture maps (equirectangular, dual paraboloid, and octahedral), and stitch the other types of maps back into cube maps. The utility allows for flexibility in the image size of the conversion - the user can specify the desired image width, and the height is computed (cube, paraboloid, and octahedral mappings are square, and spherical maps are generated to have 16:9 aspect ratio). Moreover, the utility is sampling-agnostic, so the user can select whether to use uniform or jittered sampling over the pixels, as well as the number of samples to use per pixel. The rest of this paper discusses the mathematical framework for projecting from cube maps to equirectangular, dual paraboloid, and octahedral environment maps, as well as the mathematical framework for the inverse projections. We also describe two sampling techniques: uniform sampling and correlated multi-jittered sampling. We perform an evaluation of the sampling techniques and a comparative analysis of the different projections using objective image quality assessment metrics.

Citation

Journal of Research (NIST JRES) -

Volume

122

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/jres.122.025

Local Download

Keywords

stitching, projection, cube-maps

Citation

Sriram, V. and Griffin, W. (2017), A Sampling-Agnostic Software Framework for Converting Between Texture Map Representations of Virtual Environments, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/jres.122.025, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923191 (Accessed September 8, 2024)