Detection of infrared spot small targets against complex sky background by using GST

The shortcomings of traditional methods of clutter suppression were considered. An infrared spot target detection method was presented based upon generalized structure tensor (GST). The orientation field was computed using first symmetry derivative of 2D Gaussian. The spot small target was considered as circle symmetry pattern. According to GST detection theory the corresponding complex filter was applied to the orientation field and the certainty image was computed. The complex degree of image was evaluated using information entropy and the segmentation threshold was determined by the evaluation result. The detection results were obtained after segmenting the certainty image and falsetarget deletion, the experiments were performed. The results show the proposed method could detect efficiently spot small target in complex sky background and the detection probability is up to 96%, which is superior to conventional methods.