plenoptik

Plenoptik, or plenoptic imaging, is the study and practice of capturing and rendering the plenoptic function, a theoretical description of the light that travels through a scene. The plenoptic function encompasses light as a function of position, direction, wavelength, time, and other factors. In practical terms, most plenoptic imaging implements a four-dimensional light field L(x, y, u, v), describing the radiance along rays at spatial coordinates (x, y) and directions parameterized by (u, v).

A common realization uses a microlens array placed near the image sensor, usually behind a main lens. Each microlens records light from a different direction, together sampling angular information about the scene. With computational processing, the captured data can be refocused after exposure, and depth information can be inferred to produce 3D renderings or synthetic views from novel viewpoints.

Historically, the concept builds on the plenoptic function introduced by Adelson and Bergen in 1991 and was formalized for imaging with a microlens-based camera by Ng and colleagues in 2005. The term plenoptik reflects both the theoretical framework and the practical imaging techniques that aim to capture light fields rather than a single 2D image.

Applications span photography, where post-capture focus and perspective changes are possible, to computer vision, robotics, and microscopy, where depth estimation and volumetric rendering are valuable. Limitations include a trade-off between angular and spatial resolution, reduced native sensor resolution, light efficiency concerns, and increased computational requirements, which have spurred continuing research in alternative capture schemes and reconstruction algorithms.