Computational Photography

Computational Illumination

by dr. Francho Melendez

lab 4

  • difficulties?
  • questions?
  • PCA?

today's schedule

  • Recap
  • coded illumination
    • Flash-no flash
    • Temporal coding
    • Directional coding
    • Spatial coding
    • Some SIGGRAPH
  • Lab 5

recap

computational photography

plenoptic function

  • plenoptic imaging

  • coded photography

  • computational displays

  • capturing light transport

computational photography

plenoptic imaging (epsilon photography)

coded photography

overview

coded illumination

  • Flash-no flash
  • Temporal coding
  • Directional coding
  • Spatial coding
  • Some SIGGRAPH

flash no-flash

denoising

denoising

Cross-Bilateral Filter based Approach

removing flash artifacts

[Agrawal, Raskar, Nayar, Li; Siggraph05]

removing flash artifacts

[Agrawal, Raskar, Nayar, Li; Siggraph05]

removing flash artifacts

[Agrawal, Raskar, Nayar, Li; Siggraph05]

removing flash artifacts

[Agrawal, Raskar, Nayar, Li; Siggraph05]

removing flash artifacts

  • dark buildings
  • unkown shapes
  • reflections

removing flash artifacts

  • well-lit buildings
  • tree, street shapes
  • reflections on windows

removing flash artifacts

combination

removing flash artifacts

removing flash artifacts

several llumination coding strategies

temporal coding

temporal coding

motion tracking

  • motion capture, unique temporal code for LEDs
  • e.g. phase space:
    • 960 fps
    • < 10 ms latency
    • visible or IR LEDs

time of flight

pulse systems: LIDAR

Light Detection And Raging

Typically requires scanning

$t = \frac{2d}{c}$

$c \approx 3 * 10^8 \frac{m}{s}$

pulse systems: LIDAR

small, usually need scanning

pulse systems: LIDAR

pulse systems: LIDAR

continues wave

comercial devices

continues wave

continues wave

continues wave

continues wave

continues wave

continues wave

continues wave

continues wave

kinect fusion

kinect fusion

directional coding

directional coding

additive nature of light

light stage

light stage 1

light stage: used in Spiderman 2

light stage 3

light stage 6

light waving

Estimating Light Positions From Photographs Alone

image-based relighting

image-based relighting

image-based relighting: lab

photometric stereo

photometric stereo

photometric stereo

photometric stereo

diffuse (Lambertian) surfaces are viewpoint independent

$I = \rho\begin{bmatrix}L_x & L_y & L_z\end{bmatrix}\begin{bmatrix}N_x\\ N_y \\ N_z\end{bmatrix}$

photometric stereo

$\begin{bmatrix}I^{(1)} \\ I^{(2)} \\ I^{(3)} \end{bmatrix} = \rho \begin{bmatrix} L_x^{(1)} & L_y^{(1)} & L_z^{(1)} \\ L_x^{(2)} & L_y^{(2)} & L_z^{(2)} \\ L_x^{(3)} & L_y^{(3)} & L_z^{(3)} \end{bmatrix} \begin{bmatrix} N_x\\ N_y \\ N_z \end{bmatrix}$

$I = L \cdot N$



diffuse (Lambertian) surfaces are viewpoint independent

assume albedo is constant, invert matrix $N = L^{-1} \cdot I$

photometric stereo

spatial coding

spatial coding

spatial coding

spatial coding

spatial coding

spatial coding

kinect pattern

kinect pattern

structure lighting

structure lighting

structure lighting

some SIGGRAPH papers

Separation of Global and Direct Illumination

Separation of Global and Direct Illumination

Doppler Time-of-Flight Imaging

Relighting with 4D incident light fields: relighting

Relighting with 4D incident light fields: capture

Relighting with 4D incident light fields: relighting

Confocal Imaging

show video

today's lab

Due: 24 November

  • Photometric Stereo
  • Relighting Images

http://gl.ict.usc.edu/Data/LightStage/

http://www.pauldebevec.com/Probes/

http://gl.ict.usc.edu/Data/HighResProbes/

announcements

http://franchomelendez.com/Uwr/teaching/COMPHO/_LECTURES/L6/computational_illumination.html

http://franchomelendez.com/Uwr/teaching/COMPHO/Labs/Lab5.zip


franchomelendez@cs.uni.wroc.pl

credits and references and aditional readings

These slides have been prepared with materials, slides, and discussions from the following.

Ramesh Raskar

Paul Debevec

Richard Szeliski