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:

$\stackrel{\mathbf{~}}{\mathbf{n}}\mathbf{=}\mathbf{(}{\mathbf{S}}^{\mathbf{T}}\mathbf{S}{\mathbf{)}}^{\mathbf{-}\mathbf{1}}{\mathbf{S}}^{\mathbf{T}}\mathbf{I}$

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