To make the perfect fit for shoes during production, Elinvision (Kaunas, Lithuania; www.elinvision.com) has developed a 3-D foot scanner. In less than 10 s, the system captures a 2-D color footprint and 3-D foot/shoe last shape by using laser triangulation. The development team, led by managing director Donatas Valin?cius and partners from an orthopedic shoe production company, is also developing new equipment and software for integrating the technology into producing shoes for everyday use.
The system consists of four laser projectors and eight monochrome cameras for 3-D surface scanning and one color camera for acquiring the footprint image—all cameras are IEEE 1394 Firefly MV cameras from Point Grey Research (Richmond, BC, Canada; www.ptgrey.com). All camera lenses have a focal length of 4 mm. The scanner software was developed in Borland C++.
The scanning unit is mounted on a linear actuator and provides both high speed (scanning rate of 5–20 s depending on accuracy requirements) and high resolution (±0.25 mm). Four uniform laser lines are projected onto a foot and the profile is digitized at 30 frames/s.
Reprinted with permission from the Vision Systems Design article, "3-D imaging system measures foot ", featured in the May 2009 issue.