Time-of-Flight cameras “see” by emitting pulses of invisible infrared light, then timing how long it takes for them to reflect off surfaces in the environment and return to the camera. Because light travels at a constant speed, the amount of time taken for light to travel this distance is proportional to the distance the light has traveled — this is known as the Time-of-Flight (ToF) principle.1
Measuring the time taken for an infrared pulse to return to the camera enables a Time-of-Flight camera to calculate the round-trip distance that the light pulse traveled, and hence the distance of the surface that the light reflected from.
What can a Time-of-Flight camera do?
By measuring the distance of multiple points in its Field of View, a Time-of-Flight camera can effectively take 3D snapshots of the world around it. In an image produced by a Time-of-Flight camera, the brightness of each pixel corresponds to the depth (or distance) of that part of the scene.
Compared to other depth-sensing technologies (like structured light or stereo vision systems), Time-of-Flight cameras are relatively cheap.2 They’re also versatile: because Time-of-Flight cameras detect the light they emit, they work perfectly in low-light conditions.
Capable of frame rates more than 130 frames per second, Time-of-Flight cameras are ideally suited to real-time applications. In addition, small form-factors and low rates of power consumption mean that Time-of-Flight cameras can be easily integrated into a variety of different systems.
Time-of-Flight camera applications
Time-of-Flight cameras have a wide range of applications that take advantage of their high frame rate and wide Field of View. These include gesture recognition in smart phones, robot navigation, and measurement of packages and products.
Time-of-Flight cameras are particularly well-suited to people counting applications. By quickly and accurately recognizing people entering and exiting, Time-of-Flight cameras can provide valuable occupancy data with none of the privacy concerns associated with other people counting technologies.
Introducing People Counting L-XL
People Counting L-XL from Terabee is a people counting device based on Time-of-Flight technology. Fixed above a doorway, the People Counting L-XL provides immediate access to valuable real-time occupancy data.
By revealing exactly how spaces are used, the People Counting L-XL provides data that helps make spaces safer, more effective, and more comfortable. Applications include:
- Maximizing real-estate expenditure and use of space in offices
- Automating lighting, heating, and other systems in smart building applications
- Optimizing staff scheduling and improving customer experiences in shops and other commercial spaces
Crucially, the People Counting L-XL is intrinsically anonymous: low spatial resolution ensures that no identifying information is captured, while smart onboard image-processing algorithms can still reliably count traffic with 98% accuracy or higher.
The People Counting L-XL features a wide 74° x 57° detection area, enabling it to monitor a 3.4 m wide area from a height of 4 m. Multiple devices can be easily synchronized to cover wider areas.