Gloss Perception in Painterly and Cartoon Rendering
![realisticnpr_main.pdf [18.2Mo]](/reves/Basilic/images/pdf.png)
Depictions with traditional media such as painting and drawing represent scene content in a stylized manner. It is unclear however how well stylized images depict scene properties like shape, material and lighting. In this paper, we describe the first study of material perception in stylized images (specifically painting and cartoon) and use non photorealistic rendering algorithms to evaluate how such stylization alters the perception of gloss. Our study reveals a compression of the range of representable gloss in stylized images so that shiny materials appear more diffuse in painterly rendering, while diffuse materials appear shinier in cartoon images. From our measurements we estimate the function that maps realistic gloss parameters to their perception in a stylized rendering. This mapping allows users of NPR algorithms to predict the perception of gloss in their images. The inverse of this function exaggerates gloss properties to make the contrast between materials in a stylized image more faithful. We have conducted our experiment both in a lab and on a crowdsourcing website. While crowdsourcing allows us to quickly design our pilot study, a lab experiment provides more control on how subjects perform the task. We provide a detailed comparison of the results obtained with the two approaches and discuss their advantages and drawbacks for studies like ours.
ACM, 2013. This is the authors version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definite version will be published in ACM TOG.
Images and movies
![painterly_appli_opacity_8.png [85Ko]](http://www-sop.inria.fr/reves/Basilic/2013/BODRA13/painterly_appli_opacity_8.png)
See also
The supplemental files (46MB) contains the stimulus images, the collected data and the plots for all subjects.
See also the slides (17MB) of our Siggraph talk.
Further hindsights: our data suggests that when matching similar materials in the mid-range gloss, an increase in contrast tend to mask a decrease in sharpness, and vice versa. This observation differs from the perceptual independence reported in prior work [Pellacini et al. 2000, Fleming et al. 2003]. However, these previous studies measured independence for materials with relatively high sharpness (d >= 0.9), while we also considered more diffuse materials (up to d=0.8).
BibTex references
@Article{BODRA13,
author = "Bousseau, Adrien and O Shea, James P. and Durand, Fr\'edo and Ramamoorthi, Ravi and Agrawala, Maneesh",
title = "Gloss Perception in Painterly and Cartoon Rendering",
journal = "ACM Transactions on Graphics",
number = "2",
volume = "32",
month = "April",
year = "2013",
url = "http://www-sop.inria.fr/reves/Basilic/2013/BODRA13"
}