1. A method for detecting a damaged or missing machine part, the method comprising: (a) capturing images of a machine and a background, wherein the background moves relative to the machine over time (b) selecting time-separated images which reflect movement of the background relative to the machine; (c) generating a displacement image from the selected time-separated images, wherein the displacement image provides an indication of movement of each pixel represented in the displacement image between the selected time-separated images; (d) comparing the machine from the displacement image with a model machine; and (e) identifying a damaged or missing machine part from the comparison of the machine from the displacement image and the model machine.