people detection can provide valuable metrics that can be used by businesses , such as retail stores . such information can be used to influence any number of business decisions such a employment hiring and product orders . the business value of this data hinges upon its accuracy . thus , a method according to the principles of the current invention outputs metrics regarding people in a video frame within a stream of video frames through use of an object classifier configured to detect people . the method further comprises automatically updating the object classifier using data in at least a subset of the video frames in the stream of video frames .