Infrared Small Target Detection Method Based On Maritime Scene Perception

Maritime infrared small target detection plays a very important role in the field of safeguarding marine security and marine rescue.The long-distance ship target degenerates into a small spot in an infrared image,which has the characteristics of small size,weak intensity,serious lack of texture information,and is easily disturbed by noise.Meanwhile,the background clutter such as dense sea glints,sea surface bright band-like zone with high grayscale,and island clutters seriously affect the detection performance of long-distance infrared small targets,which can easily lead to target missed detection and false alarms.In this thesis,the main work is to focus on the key technologies that develop the detection performance of infrared small targets under the complex maritime background.The maritime scene perception information is constructed by sensing the regions where the non-stationary sea surface background clutters components exist and their fluctuation states,and the signal processing method adapted to the background clutter is adopted to refine the detection of small targets.The main research contents and innovations are listed as follows:Firstly,the structure tensor and Hough transform of the infrared image are used to detect the sea-sky island region.Heuristic segmentation algorithm and variance weighted information entropy are used to perceive sun glints such as fish scale-like wave and sea surface bright band-like zone.So,the scene information of sea-sky region,island region,flat sea region,fluctuation sea region is constructed.Secondly,aiming at the characteristics of clutter components,adaptive signal processing is used to suppress clutter and enhance the target signal-to-clutter ratio.A clutter suppression and target enhancement algorithm based on directional difference is proposed to suppress clutters and highlight target signal for sea-sky island region with strong structural edge.A white top-hat transform is used to suppress clutter in flat sea region.Aiming at fluctuation sea region of sea glints and sea surface bright band-like zone,a fusion gray gradient clutter suppression method is proposed to suppress the background,greatly reducing the interference caused by sea clutters.Then,after clutter suppression,target extraction is carried out by using targeted methods.The detection results of each region are normalized to the same intensity range and integrated.Constant false alarm threshold segmentation strategy is used to detect targets in sea-sky island region and fluctuating sea region.While,peak judgment strategy of Gaussian surface fitting is used to detect the target for flat sea region.Finally,for the scattered false alarm points in target detection,the multi-frame correlation of the space-time trajectory is used to confirm the target and eliminates the false alarm.Compared with the existing advanced infrared image small target signal detection methods,the experimental results show that the proposed single-frame detection method based on maritime scene perception can effectively adapt to different maritime background clutter,and can not only effectively increase the signal-to-clutter ratio gain and the background suppression factor,but also improve the accuracy and robustness of small target detection in complex backgrounds.