Luminance Luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted or reflected from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m). A non-SI term for the same unit is the nit. The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m. Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. The luminance
Pushforward measure Pushforward measure In measure theory, a discipline within mathematics, a pushforward measure (also push forward, push-forward or image measure) is obtained by transferring ("pushing forward") a measure from one measurable space to another using a measurable function. Given measurable spaces formula_1 and formula_2, a measurable mapping formula_3 and a measure formula_4, the pushforward of formula_5 is defined to be the measure formula_6 given by This definition applies "mutatis mutandis" for a signed or complex measure. The pushforward measure is also denoted as formula_9, formula_10, or formula_11. Theorem: A measurable function "g" on "X" is integrable with respect to the pushforward