Microcontrast and Blur in Imaging Systems

Abstract

Experience in measuring television impairments suggests that for many imaging systems a practical objective test concerned with the definition or sharpness component of picture quality might be based on the concept of “microcontrast”. This term, as the opposite of “macrocontrast”, is taken to refer to the relative contrast of picture details as a function of their size. Some preliminary experiments on photographic films and lenses have been made with targets in which "details" are represented by sequences of isolated graduated-width “slits”. The impairment, termed “blur”, caused by loss of contrast in fine details can be assessed by a general-purpose method of subjective testing.