1. A method comprising: receiving data representing imagery that depicts an object, the imagery captured by a portable device, the portable device comprising a camera and a microphone; determining one or more descriptors relating to the object in the imagery, said determining including collecting descriptors associated with other imagery or audio; processing said descriptors in discerning whether the imagery depicts an object that is likely of a first class or a second class or a third class, said processing being performed by one or more electronic processors configured to perform such act; and taking an action dependent on whether the imagery depicts an object that is likely of a first class or a second class or a third class.