An Overview of Depth Cameras and Range Scanners Based on Time-of-Flight Technologies

TL;DR

This paper provides a comprehensive overview of time-of-flight (TOF) depth cameras, explaining their measurement principles, designs, calibration methods, and the integration with color cameras, highlighting their advantages and challenges.

Contribution

It offers a detailed review of TOF camera technologies, including both pulsed-light and continuous-wave systems, and discusses calibration and combined system benefits.

Findings

Different TOF measurement principles are explained.

Review of existing TOF camera designs and calibration methods.

Discussion on benefits and challenges of combined TOF and color systems.

Abstract

Time-of-flight (TOF) cameras are sensors that can measure the depths of scene-points, by illuminating the scene with a controlled laser or LED source, and then analyzing the reflected light. In this paper, we will first describe the underlying measurement principles of time-of-flight cameras, including: (i) pulsed-light cameras, which measure directly the time taken for a light pulse to travel from the device to the object and back again, and (ii) continuous-wave modulated-light cameras, which measure the phase difference between the emitted and received signals, and hence obtain the travel time indirectly. We review the main existing designs, including prototypes as well as commercially available devices. We also review the relevant camera calibration principles, and how they are applied to TOF devices. Finally, we discuss the benefits and challenges of combined TOF and color camera systems.