Decomposing intensity gradients into information about shape and material
BARLA, Pascal
Laboratoire Photonique, Numérique et Nanosciences [LP2N]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Melting the frontiers between Light, Shape and Matter [MANAO]
Laboratoire Photonique, Numérique et Nanosciences [LP2N]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Melting the frontiers between Light, Shape and Matter [MANAO]
BARLA, Pascal
Laboratoire Photonique, Numérique et Nanosciences [LP2N]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Melting the frontiers between Light, Shape and Matter [MANAO]
< Leer menos
Laboratoire Photonique, Numérique et Nanosciences [LP2N]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Melting the frontiers between Light, Shape and Matter [MANAO]
Idioma
en
Article de revue
Este ítem está publicado en
Journal of Vision. 2013-07-24, vol. 13, n° 9, p. article 443
Association for Research in Vision and Ophthalmology
Resumen en inglés
Recent work has shown that the perception of 3D shapes, material properties and illumination are inter-dependent, although for practical reasons, each set of experiments has probed these three causal factors independently. ...Leer más >
Recent work has shown that the perception of 3D shapes, material properties and illumination are inter-dependent, although for practical reasons, each set of experiments has probed these three causal factors independently. Most of these studies share a common observation though: that variations in image intensity (both their magnitude and direction) play a central role in estimating the physical properties of objects and illumination. Our aim is to separate retinal image intensity gradients into contributions of different shape and material properties, through a theoretical analysis of image formation. We find that gradients can be understood as the sum of three terms: variations of surface depth conveyed through surface-varying reflectance and near-field illumination effects (shadows and inter-reflections); variations of surface orientation conveyed through reflections and far-field lighting effects; and variations of surface micro-structures conveyed through anisotropic reflections. We believe our image gradient decomposition constitutes a solid and novel basis for perceptual inquiry. We first illustrate each of these terms with synthetic 3D scenes rendered with global illumination. We then show that it is possible to mimic the visual appearance of shading and reflections directly in the image, by distorting patterns in 2D. Finally, we discuss the consistency of our mathematical relations with observations drawn by recent perceptual experiments, including the perception of shape from specular reflections and texture. In particular, we show that the analysis can correctly predict certain specific illusions of both shape and material.< Leer menos
Orígen
Importado de HalCentros de investigación