Bayesian estimation
likelihood
posterior (unnormalized)
Bayesian estimation
Goal is to choose the label (skin or ~skin) that maximizes the posterior
this is called Maximum A Posteriori (MAP) estimation
Suppose the prior is uniform:  P(skin) = P(~skin) =
in this case                                          ,
maximizing the posterior is equivalent to maximizing the likelihood
»                                                    if and only if
this is called Maximum Likelihood (ML) estimation