1. A method comprising: receiving a plurality of inputs, each of the inputs being received from a respective one of a plurality of optical sensors; classifying each of the plurality of inputs using machine learning as to whether the inputs are indicative of detection of an object by a respective said optical sensor, said classifying including: using a first classifier to perform the classifying by taking as an input an image that includes both infrared light and ambient light and an image having ambient light subtracted from the infrared light and generating a probability map that describes of detection of the object by respective ones of the plurality of optical sensors; and using a second classifier to perform the classifying based at least in part on the input having the image that includes both infrared light and ambient light; and determining a location of the object using a result of the classifying.