Summary: Uniformity and View Independence in 4D Light-Field Models
Emilio Camahort Francisco Abad
Departmento de Sistemas Inform´aticos y Computaci´on
Universidad Polit´ecnica de Valencia
Camino de Vera s/n
Image-based models have recently become an alternative to geometry-based models for computer graphics. They
can be formalized as specializations of a more general model called light field or plenoptic function. The light field
represents radiance arriving at any point in 3D space along every possible direction. In practical applications the
light field is modeled as a function that varies over the 4D space of oriented lines.
Modeling the light field requires a good parameterization of the set of oriented lines. Four parameterizations have
been proposed. They can be classified into two clases. Planar parameterizations were inspired by traditional
two-step holography and are known to bias light-field sampling densities in particular directions. Spherical, or
isotropic, parameterizations were introduced to make the image quality of light-field rendering view independent.
In this paper, we study 4D light-field parameterizations and their suitability for rendering. Our study focuses on
continuous representations of the light field, then relates statistical biases in the continuous domain to sampling
biases in the discrete domain. We formalize the concepts of uniformity and view independence in the context of