Recently, I have heard that structured light is specifically structured light. In
layman's terms, structured light is a system structure composed of a projector and a camera. After the projector is used to project specific light information onto the surface of the object and the background, it is collected by the camera. According to the change of the light signal caused by the object, the position and depth of the object are calculated, and then the entire three-dimensional space is restored. It can be considered as a three-dimensional scanner.
Three-dimensional scanners can be compared to cameras. Their sight range is cone-shaped, and the collection of information is limited to a certain range. The difference between the two is that the camera captures color information, while the three-dimensional scanner measures distance. Since the measured result contains depth information, it is often referred to as a depth image or a ranged image.
Similar to TOF technology, TOF is the abbreviation of Time of Flight technology, that is, the sensor device emits modulated near-infrared dao light, which is reflected after encountering the object, and the sensor device calculates the light emission and The reflection time difference or phase difference is used to convert the distance of the shot scene to generate depth information. In addition, combined with traditional camera shooting, the three-dimensional outline of the object can be presented in a topographic map with different colors representing different distances.
The difference between structured light and TOF is still very different. Structured light technology has lower power consumption and more mature technology, which is more suitable for static scenes. The TOF scheme has lower noise at long distances and a higher FPS, so it is more suitable for dynamic scenes.
At present, structured light technology is mainly used in unlocking and secure payment, and its application distance is limited. Like Apple’s latest products and Aobi Zhongguang’s AR somatosensory products, they use structured light technology. The TOF technology is mainly used for rear camera photography of smart phones, and has a certain effect in AR, VR and other fields (including 3D photography, somatosensory games, etc.).