Abstract: A system for detecting a class of objects at a location, for example humans on a conveyor belt. A thermal camera may be used to detect objects and to detect the variance of the heat distribution of objects to classify them. Objects detected in an image from one camera may be detected in an image from another camera using geometric correction. A color camera may be used to detect the number of edges and the number of colors of an object to classify it. A color camera may be used with an upright human body classifier to detect humans in an area, and blobs corresponding to the detected humans may be tracked in a thermal or color camera image to detect if a human enters an adjacent forbidden area such as a conveyor belt.