Since the birth of information theory, to understand, study, and optimize optical imaging systems from the information–theoretic viewpoint has been an important research subfield of optical imaging, accompanied by a series of corresponding advances. However, since the “direct point-to-point” image information acquisition mode of traditional optical imaging systems, which directly performs one-to-one signal mapping from the object to the detection plane, lacks a “coding–decoding” operation on the image information, related studies based on information theory are more meaningful in the theoretical sense, while almost acting as icing on the cake for the optimization and design of practical systems and contributing little to substantive breakthroughs in further imaging capabilities. With breakthroughs in modern light-field modulation techniques as well as ghost imaging techniques, which establish point-to-point image signal reproduction based on high-order correlation of light fields, currently, it is able to encode the image information with controllable spatiotemporal light-field fluctuations during the ghost imaging process. Combined with modern digital photoelectric detection technologies, ghost imaging systems behave more in line with the modulation–demodulation information transmission mode compared to traditional optical imaging. This puts forward imperative demands and challenges for understanding and optimizing ghost imaging systems from the viewpoint of information theory, as well as bringing more development opportunities for the research field of information optical imaging. This article will briefly review the development of information optical imaging since the birth of information theory, overview its current research status by combining with latest related progresses in ghost imaging, and discuss the potential developing tendency of this research topic.