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NoRM: no-reference image quality metric for realistic image synthesis

Research output: Contribution to journalJournal article

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  • Robert Herzog
  • Martin Cadik
  • Tunc Ozan Aydin
  • Kwang In Kim
  • Karol Myszkowski
  • Hans-Peter Seidel
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<mark>Journal publication date</mark>05/2012
<mark>Journal</mark>Computer Graphics Forum
Issue number2 Pt 3
Volume31
Number of pages10
Pages (from-to)545-554
Publication statusPublished
Original languageEnglish

Abstract

Synthetically generating images and video frames of complex 3D scenes using some photo-realistic rendering software is often prone to artifacts and requires expert knowledge to tune the parameters. The manual work required for detecting and preventing artifacts can be automated through objective quality evaluation of synthetic images. Most practical objective quality assessment methods of natural images rely on a ground-truth reference, which is often not available in rendering applications. While general purpose no-reference image quality assessment is a difficult problem, we show in a subjective study that the performance of a dedicated no-reference metric as presented in this paper can match the state-of-the-art metrics that do require a reference. This level of predictive power is achieved exploiting information about the underlying synthetic scene (e.g., 3D surfaces, textures) instead of merely considering color, and training our learning framework with typical rendering artifacts. We show that our method successfully detects various non-trivial types of artifacts such as noise and clamping bias due to insufficient virtual point light sources, and shadow map discretization artifacts. We also briefly discuss an inpainting method for automatic correction of detected artifacts.