Communications of the ACM

I M A G E C O U R T E S Y O F T E C H C R U N C H . C O M

the fidelity of the previously used technology. Not surprisingly, as the technology has improved, so has the demand for devices with embedded 3D sensing technology, according to Anand Joshi, a principal analyst with technology research firm Tractica LLC.

“Cameras have become really cheap and are being integrated into a wide range of devices,” Joshi says, noting that the growth and availability of computer vision technology and the software to extract depth information has enabled a large application development ecosystem to thrive, thereby supporting even more innovations.

Another 3D imaging technique that may support more advanced functionality is called stereopsis, or stereovision. This technology uses a sensor

SENSOR TECHNOLOGY IS de- signed to allow machines to interact with real-world in- puts, whether they are hu- mans interacting with their smartphones, autonomous vehicles navigating on a busy street, or robots using sensors to aid in manufacturing. Not surprisingly, three-dimensional (3D) sensors, which allow a machine to understand the size, shape, and distance of an object or objects within its field of view, have attracted a lot of attention in recent months, thanks to their inclusion on Apple’s most-ad-vanced (to date) smartphone, the iPhone X, which uses a single camera to measure distance.

Indeed, the TrueDepth system, which replaces the fingerprint-based TouchID system on the Apple handset, shines approximately 30,000 dots outward onto the user’s face. Then, an infrared (IR) camera captures the image of the dots, which provides depth information based on the density of the dots (closer objects display a dot pattern that is spread out, whereas objects that are farther away create a denser pattern of dots. Altogether, the placement of these dots creates a depth map with 3D data that is used to supply the system with the information it needs to check for a facial identity match, which then unlocks the device. The key advantage to this single-camera system and others like it is the relatively low cost of implementation.

For many consumers, their first
exposure to 3D sensing technology
came in 2010, in the form of Micro-
soft’s groundbreaking Kinect mo-
tion-sensing input device designed
for the Xbox gaming consoles and
Windows PCs. Utilizing a chipset
from Israeli developer PrimeSense
(which was since purchased by Apple
in November 2013), the 3D scanner
system called Light Coding incorpo-
rated an IR emitter and an IR depth
sensor. The emitter projected infra-
red light beams, and the depth sen-
sor read those IR beams that were re-
flected back to the sensor. The
reflected beams were converted into
depth information that allowed the
distance between an object and the
sensor to be measured. The result
was a gaming system that could accu-
rately track a player’s motion, so long
as they stayed within an approximate-
ly six-square-meter zone in front of
the Kinect bar.

In subsequent versions of the Xbox, Microsoft replaced the PrimeSense technology with its own time-of-flight sensor technology, which features wide-angle coverage and three times