The light field in natural scenes

This thesis focuses on the properties of light fields with respect to object appearance. More specifically, our interest was mainly directed to the structure and spatial variation of light fields in natural scenes. We approached the structure of light fields by means of spherical harmonics which allows one to divide the complicated spherical...

Perceptual metrics of light fields

Structures of Physical and Visual Light Fields: Measurement, Comparison and Visualization

It is impossible to see the light in an empty space, we can only observe light as emission from a light source or reflections from objects. Yet, human observers can estimate the illumination in empty parts of an observed scene, based on the appearance of surrounding objects. This dissertation presents studies on human sensitivity to the light...

This is not a painting: Scanning and printing a painting's appearance

The appearance of a painting cannot solely be described by the depiction that it presents to the viewer. When viewing the artifact in real life, we find that the painted surface is in effect a three-dimensional landscape of paint. Paintings, “moveable, largely two-dimensional images created for the primary purpose of providing a visual...

On Probing Appearance: Testing material-lighting interactions in an image-based canonical approach

Materials are omnipresent. Recognizing materials helps us with inferring their physical and chemical properties, for instance if they are compressible, slippery, sweet and juicy. Yet in literature, much less attention has been paid to material perception than to object perception. This dissertation presents studies on a method to systematically...

Convincing stuff: Disclosing perceptually-relevant cues for the depiction of materials in 17th century paintings

This thesis explores convincing stuff depicted in 17th century paintings, with the primary aim of understanding their visual perception. ”Stuff” is the term first introduced by Edward Adelson in 2001 to differentiate materials from objects, and to call attention on the research gap in material perception. In an interesting parallel, the...

On the Painterly Depiction of Materials: An Interdisciplinary Study on the Depiction and Perception of Materials within Paintings

The world around us is filled with materials. Our ability of visual material perception informs us how to navigate and interact with our environment. It tells us, for example, whether food is fresh, if a chair is strong enough to sit on, how much force to use to pick up a glass, etc. Painters have studied how to depict the world and the...

Light and Spectra in the Wild - Spectral Structures of Light Fields: Measurement, Simulation and Visualisation

The study of the light field has become a valuable framework for capturing and analysing the complex distribution of light in natural environments. The directional, spatial, temporal and spectral structure of light, collectively influence the optical information available to an observer and thus impact our perception of the surrounding world....