laserstructuredlight

Laser structured light is a 3D measurement technique that uses a laser to project a known light pattern onto a scene and captures the deformation of that pattern with one or more cameras to reconstruct surface geometry. By encoding spatial or temporal information into the projected pattern, a scanner can resolve the three-dimensional coordinates of many surface points.

Principle and methods: A laser line, dot, or grid is projected onto the object. The captured image shows distortions caused by the surface topography. Using triangulation between the projector and the camera, depth information is computed. Enhanced methods employ phase-shifting, multiple patterns, or time-multiplexed encoding to recover dense point clouds or even full 3D surfaces from a single view or with multiple views.

Hardware and safety: Typical systems include a laser source, projection optics, one or more cameras, and calibration and synchronization hardware. Lasers are selected for coherence, wavelength, and power, with eye and skin safety considerations. Commercial devices are often designed to meet safety classifications (for example Class 1 or Class 2), but strict handling and enclosure are still important.

Advantages and limitations: Laser-based structured light can operate at longer range and under certain ambient conditions compared with some white-light systems, and can offer high precision. However, performance degrades on highly reflective or very dark surfaces, speckle noise can occur, and occlusions or shadows limit data coverage. Accurate calibration and proper setup are crucial for reliable results.

Applications and impact: The technique is used in industrial metrology, reverse engineering, quality control, automotive and aerospace inspection, cultural heritage digitization, and medical or cinematic capture, where accurate 3D models are required.