3D Sensing

 Three dimensional (3D) technology is a momentous scientific breakthrough. It is a depth-sensing technology that augments camera capabilities for facial and object recognition. The process of capturing a real-world object’s length, width, and height with more clarity and in-depth detail than can be achieved using a number of different technologies. 3D technology delivers unique advancements in the way day-to-day activities are perceived and approached.

3D is a real game-changer as manufacturers scramble to incorporate these new advancements into consumer products such as mobile phones. 3D sensing technology mimics the human visual system using optical technology, which facilitates the emergence and integration of augmented reality, AI (Artificial Intelligence), and the Internet of Things (IoT). This creates unique opportunities in consumer applications.

3D Sensing key technologies driving advancement

Many of the key technologies driving the advancement of 3D sensing have their pros and cons. Designing these new systems involve developing high-quality sensors and efficient algorithms that can leverage new and existing technologies. For example, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are becoming the dominant light source technology for 3D sensing and can replace LEDs or edge-emitting laser diodes, as they are simple, have a narrow spectrum, and a stable temperature. Stereoscopic vision, structured light pattern, and time of flight are three technologies used for 3D sensing.

Each of these technologies has its common use-cases and individual strengths, which we discuss in more detail.

Stereoscopic Vision

The stereoscopic vision technology derives its structure from the way human eyes capture any image. Two cameras are placed at slightly offset positions (just like human eyes). The two captured images are then united into one picture using the software. Small variances resulting from the different camera positions create the stereoscopic, i.e., 3D picture. In the assisted stereoscopic vision, a laser projection module is deployed, which projects dots on the object or scene to help the camera focus more easily. The captured image is processed to bring out a depth effect. For instance, this technology is used in bullet cameras installed for monitoring people’s movement at door entrances and other places. FLIR Systems (U.S) manufactures Stereo Vision Camera Systems with stereoscopic vision technology.

Structured Light Pattern

A light pattern made of either line, squares (periodic structures), or dots is projected on to an object or a scene by a laser projection module. A distorted pattern is created by the reflected light. The reflected light from the target is captured by a camera mounted triangularly to the projection module. The pattern distortion achieved by the triangulation between the projection module and the camera helps in the acquisition of 3D coordinates of the object or scene. The most common example is the True Depth Camera used in iPhone X. The front camera with this technology adds an infrared emitter that projects over 30,000 dots in a known pattern onto the user’s face. Those dots are then photographed by a dedicated infrared camera for analysis, and thus, the image analyzed is used for accessing the phone.