Structured-Light-Based System for Shape Measurement of the Human Body in Motion.

Area of Science:

• Biomedical Engineering
• Computer Vision
• Metrology

Background:

• Current human body motion measurement techniques are often impractical due to immaturity, complexity, or high cost.
• There is a need for advanced systems capable of accurate and efficient 3D body shape acquisition in dynamic scenarios.

Purpose of the Study:

• To develop and validate a novel method for multidirectional and parallel 3D human body shape acquisition in motion.
• To introduce a prototype system, 4DBODY, that addresses the limitations of existing measurement technologies.

Main Methods:

• Utilized structured light projection with multispectral separation for simultaneous, multi-angle data capture.
• Employed single-frame fringe projection for detailed 3D geometry reconstruction.
• Developed an extended phase unwrapping algorithm tailored for human body measurements, using local fringe parameters for optimal path identification.

Main Results:

• The prototype 4DBODY system achieved a working volume of 2.0 × 1.5 × 1.5 m³.
• Demonstrated measurement uncertainty below 0.5 mm and an average spatial resolution of 1.0 mm for 3D points.
• The system operates with eight synchronized 3D scanners at an acquisition frequency of 120 Hz, capturing dynamic movements effectively.

Conclusions:

• The proposed structured light method and 4DBODY system provide a practical and accurate solution for 3D human body motion measurement.
• The system's performance was validated using moving geometrical objects and actual human movements, confirming its efficacy.