Skin detection
Learn the skin region from examples
•Manually label pixels in one or more “training images” as skin or not skin
•Plot the training data in RGB space
–skin pixels shown in orange, non-skin pixels shown in blue
–some skin pixels may be outside the region, non-skin pixels inside.  Why?
Skin classifier
•Given X = (R,G,B):  how to determine if it is skin or not?