1. A method of detecting whether a selected pixel in an electronic image F(t), having a pixel color, represents human skin in motion, comprising: calculating a first probability, P 1 , indicating a likelihood that the color of the selected pixel appears within a first distribution of pixel colors observed in human skin, wherein the color of the selected pixel and the first distribution of pixel colors are represented in the CbCr color space; calculating a second probability, P 2 , indicating a likelihood that the selected pixel color appears within a second distribution of pixel colors that are observed outside of human skin, wherein the second distribution of pixel colors are represented in the CbCr color space; and calculating a third probability, P K , indicating a probability that the selected pixel represents human skin, wherein P K is a function of P 1 and P 2 ; wherein the selected pixel is determined to represent human skin in motion if an intensity difference, I, between the intensities of the selected pixel within F(t) and a temporally adjacent electronic image F(t−Δt) is greater than a threshold intensity value, T, which is a function of P K .