Fast recognition of aircraft target in complex scenes

A fast recognition algorithm based on the geometric characteristics of a target was proposed to pursue the fast and accurate recognition for the spacecraft target. In the algorithm, a target incorporated with linear and circular patterns was designed to facilitate the accurate recognition. The noises in the images were reduced by mean of a Gaussian filter. The object edges were detected by Canny operator and the sequences of edges were obtained by the single pixel tracking method. Then, the non-circular edges were excluded according to whether the four non-collinear points were located on the same circle or not and the circle detection was implemented by the geometrical property that two different arcs on the same circle have the same center and radius. Finally, the interruption was eliminated by the geometric relation between target circle and line, and the target was recognized precisely. The experimental results demonstrate that the algorithm is insensitive to noise, illumination and target rotation and efficiently recognizes the target in the complex scenes. Moreover, the processing time is less than 125 ms, which meets the requirement of real-time pose measurement of 8 frames. The algorithm has been used in an engineering prototype successfully, now.