Interactive Displays: Natural Human-Interface Technologies

Chapter 7Time-of-Flight 3D-Imaging Techniques

Daniël Van Nieuwenhove

SoftKinetic Sensors, Belgium

7.1 Introduction

In the last decade, awareness of the unique advantages of 3D imaging, resulting in new and compelling applications enabled by real-time 3D user interactions, has grown significantly. Most known techniques for 3D sensing include stereo vision, time-of-flight, and structured light methods. In this chapter, we will discuss the time-of-flight (TOF) techniques.

In the first part of the chapter, we will explain the techniques in detail, distinguishing between different time-of-flight 3D imaging approaches, such as pulsed time-of-flight and continuous time-of-flight. We will then present the operating principles and the main equations, and discuss the accuracies of these methods. Finally, we will detail the challenges and required improvements, as well as some typical values of a camera system, and the current state-of-the-art with respect to the resolutions across research centers worldwide.

7.2 Time-of-Flight 3D Sensing

Only recently, time-of-flight (TOF) 3D imaging techniques have proven their reliability for more widespread 3D applications [1–3]. Generally, in all the TOF 3D imaging schemes, a modulated light wave is sent out to the scene and its reflections are detected and used to determine the light's round trip time and distance [4]. By focusing the reflected light on a matrix of pixels, complete range images are obtained at once. Challenges in this approach ...