Fast centroid estimation algorithm for coordinates measurement of infrared markers

To determine the coordinates of infrared markers, it is very important for the binocular vision system based on lightweighted passive infrared reflective markers and infrared LED array PCB board, which is often used to measure the 3-D motion parameters of a rocket motor. Therefore, a fast centroid estimation algorithm, which segments the infrared image using self-adapting thresholding method, and then the centroid of infrared markers is calculated using improved statistical averaging technique, was developed. A comparison was made between the newly developed algorithm and other algorithms such as traditional statistical averaging, FFT and least-squares method. It is found through comparison that the new algorithm is more suitable for high-speed motion analysis due to its higher accuracy and faster processing speed. Experiments performed on real-world images show that the algorithm can greatly improve the speed of the calculation and meantime ensure the demand of precision on the basis of the better image segmentation result and improved statistical averaging technique.