Image Quality
Henri Maı̂tre · 2015
The quality of the images produced by a camera is a key concern for photographers, but the subject is a particularly complex one. This chapter simply examines the technical aspects of quality, along with their psychovisual effects via the properties of human perception. It first considers the criteria used by engineers in order to measure image quality: the signal-to-noise ratio, resolution, transfer function, sharpness and acutance. The chapter then presents work which has been carried out with the aim of establishing a global measurement of image quality, with or without a reference. It also addresses a number of methods which operate based on the use of a real reference image, before considering some examples of no-reference methods. Finally, the chapter presents a notion taken from information theory which aims to provide a single framework for regrouping various forms of impairment.