ABSTRACT
The light field, as defined by Gershun in 1936 [Gershun 36] describes the radiance traveling in every direction through every point in space. Mathematically, it can be described by a 5D function which is called the plenoptic function, in more generality sometimes given with the two additional dimensions time and wavelength. Outside a scene, in the absence of occluders, however, light intensity does not change while traveling along a ray. Thus, the light field of a scene can be parameterized over a surrounding surface; light intensity is attributed to every ray passing through the surface into any direction. This yields the common definition of the light field as a 4D function. In contrast, a single pinhole view of the scene only captures the rays passing through the center of projection, corresponding to a single 2D cut through the light field.
