Photometric Stereo

Nick Vallidis

COMP 290 project

May 3, 2000

Outline

• Brief discussion of photometric stereo

• Brief discussion of my “oops”

• Lots of results (from 4 data sets)

Photometric Stereo

• We talked about using 2 images in class

• If you use 3 images, there’s a closed-form solution and you get albedo!

Oops!

• Need to have light sources fairly close together:– Don’t get any data from a surface whose

normal is >90o from the light vector.– 2 of my light sources were ~110o apart...

Results

• The following results are from:– synthetic images of a sphere– real images of a sphere– real images of a ceramic pot– real images of a scene with sphere and pot

Synthetic Sphere Data

Input imagesUsable Data

Mask

Synthetic Sphere ResultsNeedle Diagram:

Albedo

Re-lit:

Real Sphere Data

Input imagesUsable Data

Mask

Real Sphere ResultsNeedle Diagram:

Albedo

Re-lit:

Ceramic Pot Data

Input imagesUsable Data

Mask

Ceramic Pot ResultsNeedle Diagram:

Albedo

Re-lit:

Scene Data

Input imagesUsable Data

Mask

Scene ResultsNeedle Diagram:

Albedo

Re-lit: