ABSTRACT
In this chapter, we briefly discuss the human visual system and human visual perception. We begin by defining relevant radiometric and photometric terms. Then, the human visual system is described by following light as it enters the eye and is transduced into an electrical signal by the photoreceptors. We then follow the path this signal takes through several layers of cells in the retina and onwards to the visual cortex. Although much is known about cortical visual processing, there is even more that remains unknown. We therefore describe cortical processing only at a very abstract level and only sofar as is relevant in the context of natural image statistics.
