According to the imaging procedure an infrared picture include an object image, a background image and a noise image. The object image and the background image are main body of an infrared image; noise image is the disturbance on the main body. This paper discusses the infrared image quality from three aspects: information capacity, image detail and pseudo-s/n ratio, it has fine image quality in comparison.
"Image quality evaluation of infrared image", Proc. SPIE 5640, Infrared Components and Their Applications, (10 January 2005); doi: 10.1117/12.576795; https://doi.org/10.1117/12.576795