A Time of Flight (ToF) sensor is a special type of digital camera designed to measure the distance of each image pixel from the camera. Instead of rendering a photographic image it produces an array of distance values that can be used to create a three-dimensional impression of the scene.
ToF cameras can perform scene depth measurements many times a second. First, a laser or LED light is flashed. The pulse is reflected by points on the scene back to the camera and the time for the light to return to each pixel on the ToF camera sensor is logged and computed as a distance.
This means ToF can be used to measure objects and even compute object volumes, aid camera focusing as long as the subject is not too far away, and to create 3D object models that can be used for Augmented Reality (AR) object tracking in gaming, for example. It’s worth noting that ToF sensors are relatively low resolution, e.g. 360×240 pixels, or under 90,000 scene points.