Low-light night vision technology is committed to exploring the acquisition, conversion, enhancement, recording and display of target image information at night and other low light levels, and to study its application in human life. Its achievements are concentrated in the effective expansion of human vision in the time domain, spatial domain and frequency domain. Infrared imaging technology can convert the temperature distribution and emissivity differences between the target and each part of the scene into corresponding electrical signals, and then into visible light images. The temperature resolution of the thermal imager is very high (0.01~0.1℃), which makes it easier for the observer to find the clues of the target.

 

However, low-light and infrared imaging also have their own shortcomings. Among them, low-light images have poor contrast, limited gray levels, poor instantaneous dynamic range, flicker at high gain, and halo and even illusion when strong light flickers. Infrared thermal images, on the other hand, are related to the temperature of objects and scenes, and objects will have an unnatural appearance.

 

Although low-light night vision and infrared imaging are the main technical modes of current night vision equipment, they are key technologies developed by countries around the world. However, due to the narrow spectral range that can be detected by the system under low light conditions at night, the device sensitivity and the image signal-to-noise ratio are low, so the previous low-light images and infrared thermal images are monochromatic images, and the images lack three-dimensional and depth perception. . These are not conducive to the detection of the target, so that the application of the system is limited.

 

With the development of low-light and infrared imaging technology, it has become an effective technical means to synthesize and excavate the characteristic information of low-light and infrared images and fuse them into a more comprehensive image. Night vision image fusion can enhance scene understanding, highlight targets, and facilitate faster and more accurate target detection in hidden, camouflaged, and confusing military backgrounds. Displaying the fused image in a natural form suitable for human eye observation can significantly improve the human eye's recognition performance and reduce operator fatigue.