Bayes rule
In terms of
our problem:
what we measure
(likelihood)
domain knowledge
(prior)
what we want
(posterior)
normalization term
What could we use for the
prior P(skin)?
•Could use domain
knowledge
–P(skin) may be larger if we
know the image contains a person
–for a portrait, P(skin) may
be higher for pixels in the center
•Could learn the prior from
the training set. How?
–P(skin) may be proportion of
skin pixels in training set
