New Method of Describing and Measuring the Granularity of Photographic Materials

Abstract

The thesis of this paper is that the only fully adequate way to describe the granularity of photographic materials is by means of a film noise spectrum. The film noise spectrum bears the same relation to granularity that the power spectrum (of electrical circuit theory) bears to electrical noise. The film noise spectrum includes all of the information in the previous granularity measures and readily interrelates them. It goes beyond the previous measures in that it leads to the solution of many of the signal-to-noise problems that arise in connection with the detection of target images on photographic materials.