Research And Development On Infrared Laser Three-dimensional Human Head Scanning System

Under the premise of knowing widely about human head scanning system’sdomestic and foreign development, an integrated human head scanning schemecombined with U shape structure and single axis was proposed using near-infraredlaser light source. The scheme is based on the four-axis synchronous body scanningsystem which is researched and developed by our lab, to solve the problem of theexisting head scanner not being able to acquire information on human’s hair and eyes.In this paper, the system’s mechanical structure and the hardware and software weredesigned, as well as the scanning system prototype developed. The scanningexperiments demonstrated the feasibility of the system, and succeeded in conductingsurface reconstruction of the hair point cloud. My work is mainly composed of thefollowing aspects:1. In order to attain the complete head model including of hair and eyes withhigh resolution, meanwhile considering the safely using requirements of laser product,a human head imaging scheme using980nm near-infrared laser as the light projectingsource was proposed based on the laser triangulation method. Due to the near-infraredlight’s invisibility and scattering properties, the complete head contour of humanopening eyes was acquired by scanning, which satisfied the system’s requirements ofthe scanning effects.2. Image acquisition system and synchronous scanning system were designedand developed to match the infrared laser light source. Particularly, for the purpose ofimproving the positioning accuracy of our laboratory’s four-axis synchronousscanning system which are all under independent research and development, as wellas lowering the complexity of synchronous control, an integrated single-axismechanical system based on a U-shaped cantilever beam mechanical structure wasdesigned. It used the cantilever beam to drive multiple sets of sensors to conduct thescanning, thus improving the synchronous positioning accuracy between sensors,making it convenient to realize synchronous control, and reducing the system’s cost.The technical indicators of the prototype are: Measuring Range-a cylinder area of400 mm in diameter and400mm in height, Typical Resolution-0.56mm×2.00mm×1.17mm (horizontal×vertical×deep), Scanning Time-7s.3. The integrated debugging of the system was conducted, and the performanceof the prototype was optimized. Specially, the nonlinear camera imaging model wasestablished considering distortion. By adopting Zhang Zhengyou’ s algorithm and LiYupeng’ s calibration algorithm of the V shape light with angular points, the camera’sinner parameter calibration and the sensor group’s global calibration were doneseparately.4. Scanning experiments of the cylindrical standard parts were conducted, andthe system’s scanning precision was verified. Data analyses were achieved on realpeople models’ scanned original point cloud. Also, data preprocessing such as noisereduction, downsizing and fitting were included. Allowing for the particularity of thehair point cloud, surface reconstruction was achieved using double thrice Beizeralgorithm. A fairly good reconstruction result was obtained.