Shape-from-X

约 105 个字

Shape from shading

Gradient Space Representation

A 3-dim free vector represented by gradients.(\(\frac{\partial z}{\partial z} = 1\) is omitted)

It is actually the intersection with plane \(z = 1\)

Photometric stereo

Render equation \(I = \rho \ \mathbf s^T \mathbf n\)

For different light sources:

\(\mathbf{\tilde n = (S^T S)^{-1} S^T I}\)

Shape from X

Volumetric Fusion

• 3 Steps:

  Depth-to-SDF Conversion

  Volumetric Fusion

  MeshExtraction

• Implicit representation (Signed distance field SDF)

  signed distance to the closest surface at each voxel

• Volumetric Fusion

  Weighted average of SDF from different view point

• Mesh extraction

  marching cubes.

  Classify the topology in each cube and do interpolation for the vertex