A method of feature extraction and small target detection, based on infrared polarization, which uses the technical superiority of infrared polarization imaging in artificial target detection to solve the clutter interference problem in infrared target detection, is proposed. First, using the differences in the polarization characteristics of the artificial target and the natural background, the infrared polarization information models for the target and background are established. The compositions of intensity information, polarization information, and target polarization information are extracted, and enhancement measures are analyzed. Then, the variable polarization theories are combined to extract the target polarization characteristics and suppress the background clutter. Finally, the infrared small target is detected, and comparisons with existing methods demonstrate the effectiveness and reliability of the proposed method.
After a deep study of the principle of infrared polarization imaging detection, the infrared polarization information of target and background is modeled. Considering the partial polarized light can be obtained by the superposition of natural light (unpolarized light) and linearly polarized component while ignoring the component of circularly polarized light, and combing with the degree of polarization (DOLP) and the angle of polarization (AOP), the infrared polarization information is expressed by the multiplying of an intensity factor by a polarization factor. What we have modeled not only can be used to analyze the infrared polarization information visually and profoundly, but also make the extraction of polarized features convenient. Then, faced with different application fields and based on the model, a target information enhancement program is proposed, which is achieved by extracting a linear polarization component in a certain polarized direction. This program greatly improves the contrast between target and background, and can be applied in target detection or identification, especially for camouflage or stealth target. At last, we preliminarily tested the proposed enhancement method exploiting infrared polarization images obtained indoor and outdoor, which demonstrates the effectiveness of the enhancement program.