Range Imaging as Emerging Optical Three-Dimension Measurement Technology

In recent years, the need for accurate and fast visualization, modeling, and simulation of construction and transportation environments has increased the interest in optical three-dimensional (3-D) imaging technologies. This demand has led to development of a variety of enabling range sensing systems based on passive (light) and active (laser) range scanning approaches. The many existing and emerging range imaging technologies differ greatly, however, in their functional principles and specifications. One problem is the absence of a standard terminology that allows the advantages and disadvantages of each system to be understood easily. The intention here is to classify optical range imaging techniques and investigate the differences in working methods and characteristics. In particular, 3-D video range imaging cameras as state-of-the-art, large-field-of-view, high-resolution, and high-speed range sensing devices are put into perspective with existing 3-D measurement approaches. Additional focus is given to efforts to calibrate 3-D range imaging cameras, as their prototype development status currently limits their applicability to the field because of inaccurate measurements or other ambient limitations. Application-oriented experimental results and developments in range data processing methods are presented and demonstrate that 3-D video range cameras have reached a range accuracy level that allows them to be applied to some construction and transportation work tasks, for example, to improve safety in heavy equipment operation or to generate rapid 3-D, as-built models of entire scenes.