Structured Light

Structured Light

Principles

• Projected pattern
• Distortion / displacements on objects in scene gives depth information.

Key considerations

• No texture on surfaces required.
• Single pattern - fast processing.
• Region based correspondence
• Block averaging.

Time-coded Structured Light

Principles

• Projected fringes
• Distortion / displacements on objects in scene gives depth information.
• Measure the time of emitted light and reflected response.
• Zivid utilizes a variant of this technique.

Key considerations

• Time-coded series of patterns, pixel-wise processing.
• No need for analyzing spatial neighborhood.
• Eliminates block averaging.
• No texture on surfaces required.
• Optimal combination of “space and time”.
• Utilize time as «baseline».
• Potentially most accurate 3D technology, underlying principle determines quality.
  • Traditionally slow, Zivid has made it fast!

Watch Svenn Arne describe how time-coded structured light can create point clouds here:

Keep learning!

Read the whole article about active and passive 3D vision principles here, including stereo, active stereo, laser, ToF, and structured light machine vision.