## 5 Conclusions  
In this paper, a static infrared polarization snapshot spectral imaging system (PSIFTIS) based on an infrared micro-lens array, rooftop-shaped multi-stage micro-mirror, and infrared grating polarizer array are proposed. Due to the complexity of the data structure in this system, an infrared polarization map information processing method is proposed. After the segmentation of the polarization interference image array obtained on the experimental platform, the matching of the optical path difference, and the image registration, the polarization interference data cube set is obtained. Then, the polarization interference intensity sequence of the target feature point is demodulated by Fourier transform spectroscopy to obtain the reconstructed polarization spectrum. A further experiment is carried out in the filter system with a central wavelength of 3970 nm, and the polarization spectrum is reconstructed. The experimental results show that the maximum spectral peak wavenumber error of the four polarization channels is less than 2 cm\({}^{-1}\), and the polarization angle error is within 1\({}^{\circ}\). At the same time, the polarization interference image array is processed with the steps of image preprocessing, Stokes vector calculation, and Haar wavelet transform for the decomposition and reconstruction of high- and low-frequency components, thus  
Figure 21: Fusion polarization image array.  
Figure 22: Fusion image: (**a**) unprocessed polarization image unit; (**b**) target polarization fusion image.  
implementing polarization image fusion. Compared with the unprocessed polarization image unit, the peak signal-to-noise ratio of the final target polarization image is increased by 45.67%, the average gradient is increased by 8.03%, the information entropy is increased by 56.98%, and the image quality is significantly improved. In summary, by processing the image and spectral information with PSIFTIS, a high-precision polarization spectrum and high-quality polarization image can be obtained.  
Conceptualization, B.S. and J.L. (Jinguang Lv): methodology, B.S. and J.L. (Jinguang Lv); validation, B.S., J.L. (Jinguang Lv), B.Z. and Y.C.; investigation, B.S., G.L. and Y.Z.; resources, B.Z.; writing--original draft preparation, B.S.; writing--review and editing, J.L. (Jinguqiu Liang) and W.W.; supervision, Y.Q. and K.Z.; funding acquisition, J.L. (Jinguqiu Liang). All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Jilin Scientific and Technological Development Program under grants 202302010496X, 20230508141 RC, and 20230508137 RC; the National Natural Science Foundation of China under grants 61805239, 61627819, 61727818, and 62305339; the Youth Innovation Promotion Association Foundation of the Chinese Academy of Sciences under grant 2018254; and the National Key Research and Development Program of China under grant 2022 YFB3604702.  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.