Marker Identification Using IR LEDs and RGB Color Descriptors

In optical motion capture systems, it is difficult to correctly recognize markers based on their unique identifiers (IDs) in a single frame. In this paper, we propose two types of light-emitting diodes (LEDs) and cameras, infrared (IR) and RGB, in order to correctly detect and identify all markers tracking objects in a given system. To detect and estimate the three-dimensional (3D) position of the marker, we measure IR LEDs using IR stereo cameras. Furthermore, in order to identify each marker, we calculate and compare the RGB color descriptor in the vicinity of its center. Our system consists of general IR and RGB cameras, and is easy to extend by increasing the number of cameras. We implemented an IR/RGB LED marker circuit and constructed a simple motion capture system to test the effectiveness of our system. The results show that our system can detect the 3D positions and unique IDs of markers in one frame.