DENSITY

In a facsimile system , a measure of the light transmission or reflection properties of an area of an object . ( 188 ) Note 1: Density is usually expressed as the logarithm to the base 10 of the ratio of incident to transmitted or reflected irradiance . Note 2: There are many types of density, such as diffuse, double diffuse, and specular density, each of which will usually have different numerical values for different materials. The relevant type of density depends on the type of optical system, the component materials of the object, and the surface characteristics of the object.