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

Abstract

The existing methods for measuring the shape of the human body in motion are limited in their practical application owing to immaturity, complexity, and/or high price. Therefore, we propose a method based on structured light supported by multispectral separation to achieve multidirectional and parallel acquisition. Single-frame fringe projection is employed in this method for detailed geometry reconstruction. An extended phase unwrapping method adapted for measurement of the human body is also proposed. This method utilizes local fringe parameter information to identify the optimal unwrapping path for reconstruction. Subsequently, we present a prototype 4DBODY system with a working volume of 2.0 × 1.5 × 1.5 m3, a measurement uncertainty less than 0.5 mm and an average spatial resolution of 1.0 mm for three-dimensional (3D) points. The system consists of eight directional 3D scanners functioning synchronously with an acquisition frequency of 120 Hz. The efficacy of the proposed system is demonstrated by presenting the measurement results obtained for known geometrical objects moving at various speeds as well actual human movements.

Advances in Orthotic and Prosthetic Manufacturing: A Technology Review

“…Research has also been focused into structured light using this method [58]. Unkovskiy et al [59] used a portable structured light scanner to retrieve the topology of the nose cavity and the face to design and manufacture a prosthetic nose.…”

Temperature Compensation Method for Mechanical Base of 3D-Structured Light Scanners

“…They have been used in inverse engineering [2,5] and can be a source of precise 3D models for 3D printing. In medicine, they have been used for spine curvature estimation [6,7], for gait analysis [8], for prosthetics [9,10], and for four-dimensional (4D) measurements of human bodies in motion [11][12][13]. In industry, they have been used to perform quality control [14][15][16], to support the Industry 4.0 intelligent systems [17,18], in augmented reality to support the documentation process of criminal events [19][20][21][22], and in archaeological sites or in cultural heritage conservation workshops as devices used for digitization for archiving or conducting analysis (e.g., analyzing the influence of conservation processes or for the analysis of ageing processes) [16,[23][24][25][26][27][28].…”

“…The variety of applications of 3D-structured light scanners is so extended as they can provide precise measurements of 3D geometries, often in a short time [4,[11][12][13]16,20,21,29]. A typical 3D-structured light scanner consists of 3 main units: a digital camera, a structured light projector, and a rigid mechanical frame which is a support for camera and projector [2,3,15,29,30] (see Figure 1).…”

“…There is a group of 3D-structured light scanners in which the influence of temperature on the mechanical base is much larger than that on the camera and projector: Those with a long mechanical base and large measurement volume [6][7][8]12,29]. The measurement volume of this type of scanner can be described as a cuboid, often with a size in the range of 0.…”

“…The spatial resolution is in the range of 0.1-2 mm. The mechanical base of this type of scanner is often designed as a beam or frame, with the camera and projector fixed to its ends [8,12]. Due to the presence of a long mechanical structure, thermal deformations of the mechanical base have a larger influence on scanner uncertainty than the effects of temperature on the camera and projector.…”