Photonetric Stereo

Question 1

Photo metric stereo

Answer 1

Lambertian object
Local shading model
Light source directions are known
Orthographic projection

Question 2

Reflectance map

Answer 2

Related image intensity to surface orientation for GIVEN source direction

Question 3

When trying to derive 3D from an image, need

Answer 3

multiple lighting samples from same viewpoint

Question 4

Depth from normals

Answer 4

Shape by integration

Can get the surface by summing the partial derivatives of change in surface height

Question 5

Shape by integration 2D limitations

Answer 5

Integration is good only if object shape is continuous

Is sensitive to noise

Question 6

Photo metric stereo limitations

Answer 6

Simplistic reflectance and lighting model
(Can’t do shiny things)

Camera and lights have to be distant
Calibration requirements
Integration is tricky