Adam Celarek, Wenzel Jakob, Michael Wimmer, Jaakko Lehtinen
Quantifying the Error of Light Transport Algorithms
Computer Graphics Forum, 38(4):111-121, July 2019. [paper_preprint] [Git repository]
@article{celarek_adam-2019-qelta, title = "Quantifying the Error of Light Transport Algorithms", author = "Adam Celarek and Wenzel Jakob and Michael Wimmer and Jaakko Lehtinen", year = "2019", abstract = "This paper proposes a new methodology for measuring the error of unbiased physically based rendering algorithms. The current state of the art includes mean squared error (MSE) based metrics and visual comparisons of equal-time renderings of competing algorithms. Neither is satisfying as MSE does not describe behavior and can exhibit significant variance, and visual comparisons are inherently subjective. Our contribution is two-fold: First, we propose to compute many short renderings instead of a single long run and use the short renderings to estimate MSE expectation and variance as well as per-pixel standard deviation. An algorithm that achieves good results in most runs, but with occasional outliers is essentially unreliable, which we wish to quantify numerically. We use per-pixel standard deviation to identify problematic lighting effects of rendering algorithms. The second contribution is the error spectrum ensemble (ESE), a tool for measuring the distribution of error over frequencies. The ESE serves two purposes: It reveals correlation between pixels and can be used to detect outliers, which offset the amount of error substantially.", month = jul, doi = "10.1111/cgf.13775", journal = "Computer Graphics Forum", number = "4", volume = "38", publisher = "The Eurographics Association and John Wiley & Sons Ltd.", pages = "111--121", keywords = "measuring error, light transport, global illumination", URL = "https://www.cg.tuwien.ac.at/research/publications/2019/celarek_adam-2019-qelta/", }
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