1. A process to identify a person in image data comprising: executing a training phase, the training phase comprising: using one or more body part detectors to learn one or more body parts; generating classifiers for the one or more body parts; determining a spatial distribution among the one or more of the body parts; and determining a set of probabilities, the set of probabilities relating to one or more of a probable location and scale of the person in the image data given that a particular body part detector has fired, a probability that there is a person in the image data given that a particular body part detector has fired, and a probability that a particular body part detector can fire at a particular location and a particular scale; and executing a detection phase, the detection phase comprising: applying the one or more body part detectors to an image; combining output of the one or more body part detectors; and determining a maximum of the combination of output of the one or more body part detectors.