1. A non-transitory program storage device, readable by a programmable control device and comprising instructions stored thereon to cause the programmable control device to: obtain a set of two or more image frames in an image sequence; downscale each of the obtained image frames in the set; calculate a coefficient of variation for each sample in a last received image frame in the set, the coefficient of variation being calculated across each of the images in the set; and detect motion in the last image frame by comparing each of the calculated coefficients of variation to a threshold value.