Three-dimensional body scanners capture the outside surface of the human body by using either an optical technique in combination with light-sensitive devices, or low-power radio signals (millimeter wave or microwave) (Intellifit,2007). Generally, the scan can be taken without physical contact with the body. Body-scanning systems consist of one or more light sources, one or more vision or capturing devices, software, a computer system, and a monitor screen in order to visualize the data capture process. The primary types of body-scanning systems are laser, light and microwave. Surface tracing systems also exist; however, these are not currently used for capturing the shape of human bodies. Table 5.1 lists scanners by the type of technology used to capture the image. In the optical systems, an object is first illuminated by the mechanical motion of one or more light sources, either white, infrared, or laser. Second, charged-coupled device (CCD) cameras detect and scan the reflected patterns off the object. Third, the displacement of the structured light pattern is used to calculate the distance from the subject to the CCD camera. Finally, software inverts the distance data to produce a 3D representation. According to Kaufmann (1997), during the software inversion, a certain amount of redundancy is important to overcome shadowing of arms and ears. In the radio- (or micro-) wave system, very low level sound waves are bounced off an object to identify the object’s location in space. The data collected become an electronic cloud of points that emulates the shape of the object. Software allows the extraction of measurements from the point cloud of the object.
