1. A method, performed by one or more hardware processors, comprising: receiving an image at a memory accessible by the one or more hardware processors; determining, by the one or more hardware processors, a light intensity of the image; converting, by the one or more hardware processors, a color space of each pixel in the image into a converted value based on the light intensity; selecting, by the one or more hardware processors, a classifier from a plurality of classifiers based on the light intensity; determining, by the one or more hardware processors, for each converted value, using the selected classifier, a probability that the converted value represents a skin tone; detecting, by the one or more hardware processors, presence of skin tone in the image based on the determined pixel probabilities; and detecting, by the one or more hardware processors, user presence based on the determined pixel probabilities, including determining a threshold, and selecting, for each probability in the determined pixel probabilities the probability that satisfies the threshold, where the threshold is determined by a maximum a postieri probability estimate.