Experimental Procedure for the Metrological Characterization of Time-of-Flight Cameras for Human Body 3D Measurements

Abstract

Time-of-flight cameras are widely adopted in a variety of indoor applications ranging from industrial object measurement to human activity recognition. However, the available products may differ in terms of the quality of the acquired point cloud, and the datasheet provided by the constructors may not be enough to guide researchers in the choice of the perfect device for their application. Hence, this work details the experimental procedure to assess time-of-flight cameras’ error sources that should be considered when designing an application involving time-of-flight technology, such as the bias correction and the temperature influence on the point cloud stability. This is the first step towards a standardization of the metrological characterization procedure that could ensure the robustness and comparability of the results among tests and different devices. The procedure was conducted on Kinect Azure, Basler Blaze 101, and Basler ToF 640 cameras. Moreover, we compared the devices in the task of 3D reconstruction following a procedure involving the measure of both an object and a human upper-body-shaped mannequin. The experiment highlighted that, despite the results of the previously conducted metrological characterization, some devices showed evident difficulties in reconstructing the target objects. Thus, we proved that performing a rigorous evaluation procedure similar to the one proposed in this paper is always necessary when choosing the right device.

Triangle-Mesh-Rasterization-Projection (TMRP): An Algorithm to Project a Point Cloud onto a Consistent, Dense and Accurate 2D Raster Image

“…The initial problems are solved in the modern RGB-D sensors [ 21 , 59 ]. However, there are still challenges that have not been solved [ 60 ], such as the incomplete consideration of gaps in projection, challenge (A). This method is more accurate compared to the simple SOTA projection.…”

A three-dimensional vision measurement method based on double-line combined structured light

“…TOF (Time-of-Flight) cameras operate based on the time it takes for light to propagate on the surface of an object and measure distance, offering advantages in speed and measurement range. However, in close-distance, small-scale measurement scenarios, its stability and measurement accuracy may not be as good as structured light measurement methods [8][9][10] .…”