ABSTRACT
Enthusiasts may recognize the breed of dog. Comments on such attributes as lighting, colour and composition could also be made. These aspects of visual perception are a consequence of the subtle processes of physiology and psychology operating when the two-dimensional luminance pattern contained in the image is viewed by a human observer. The processes operate on identifiable physical properties of the image, such as the structure of edges and the distribution of tones. The measurement of these physical properties forms the basis of objective image evaluation. What lies in front of the camera lens when an image is captured is a continuous luminance pattern, which can be considered as an infinite array of infinitesimal points of varying luminance. Despite these technological differences, the Fourier theory of the image formation can be applied, with certain conditions, to all the imaging systems.
