Study on design of infrared cooperative marker and extraction method of random irregular cross

The design of cooperative marker and the accuracy of target extraction are of great significance for precision of monocular pose measurement. To suit all-weather conditions in some applications, infrared cooperative marker combined by several crosses is designed, and each of the crosses is composed of a certain mount of infrared LEDs (Light Emitting Diodes) with the wavelength of 850 nanometers. When shooting at different directions, the angles between both arms of the cross and horizontal axis of the image are different and irregular. Aiming at detection of random and irregular cross, a new sub-pixel detection method based on GPI (gray projecting integration) and correlation is put forward. Experiments show that the proposed detection method is robust and can locate cross center with the accuracy prior to 0.05 pixels.