1 / 19

The Plenoptic Function

The Plenoptic Function. Lázaro Hermoso Beltrán. Previous Concepts. “The body of the air is full of an infinite number of radiant pyramids caused by the objects located in it” Leonardo Da Vinci Pencil of rays: The set of light rays passing through any point in space Plenoptic function

min
Download Presentation

The Plenoptic Function

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Plenoptic Function Lázaro Hermoso Beltrán

  2. Previous Concepts “The body of the air is full of an infinite number of radiant pyramids caused by the objects located in it” Leonardo Da Vinci • Pencil of rays: The set of light rays passing through any point in space • Plenoptic function • Plenus : complete or full • Optic

  3. Definition (I) “Radiance received along any direction V arriving at any point E in space, at any time ‘t’ and over any range of wavelength” • 7-Dimensional function

  4. Geometric Components of the pencil of ray lights ANGULAR COORDINATES • E = (Ex, Ey, Ez) • Viewpoint • . • Direction of the ray light passin trough the Viewpoint CARTESIAN COORDINATES • Comonly used in machine vision

  5. How would obtain plenoptic function • Placing an imaginary eye at every position • Record the intensity of light at every angle • For every wavelength • At every time t • It does not need specify the • direction of gaze!!

  6. The Holographic Movie Example • Black and white photo • Color photograph • Color movie • Color holographic movie

  7. Plenoptic Measurements in Human Vision • PF potential iformation available • Observer takes samples from PF • Not all the information is usefull. Enviroment has determined what is usefull (movements  predators). Enviroment constraints

  8. P.M. in Human Vision • Measurements has limited • resolution and number of • Samples • Space and time the more importants

  9. P.M. in Human Vision • An example of what we can not measure http://web.mit.edu/persci/demos/Lightness/gaz-teaching/flash/koffka-movie.swf

  10. P.M. in Human Vision

  11. Plenoptic Measurements: Red Bar Example (Vx, Vy, Vz)

  12. P.M. in Machine Vision • Develop a taxonomy of derivative types • “Periodic Table” • of visual elements • Constraints  • Available information (PF)

  13. Aplications: Image Based Rendering • IBR : Sampling and Rendering • Problem, PF is 7D function.We need reduce it! • RGB representation • Plenoptic modelling • Light Field/Lumigraph P(s, t, u, v) • 2D-Image Mosaicing

  14. RGB – Representation • Three 5-D functions

  15. Plenoptic Modelling • Without time and wavelength • Taking samples with cameras in enough close positions • We can reconstruct PF interpolating the samples

  16. Light Field • Assumption that that rays does not change intensity along direction • Parametrization rays with 2 parallel planes

  17. 2D-Image Mosacing • To paste serial 2D images to obtain a wider image. The images share the same proyection point • Panoramic mosaic or Panorama • We reconstruct a 2D Plenoptic function

  18. Interpolate Views

  19. References • E.H. Adelson and J. Bergen, “The plenoptic function andthe elements of early vision” In Computational Models ofVisual Processing, pages 3-20. MIT Press, 1991 • The Plenoptic Illumination Function Tien-TsinWong1 Chi-Wing Fu2 Pheng-Ann Heng1 Chi-Sing Leung3 • McMillan, Bishop. “Plenotic Modeling: An Image-Based Rendering System” • Shum, Kang. “A Review of Image-based Rendering Techniques”

More Related