Detecting motion in out-of-register pictures

A novel technique is described that can be applied to a sequence of pictures to detect moving objects and segment them from the stationary background. It does not require the pictures to be in-register, and is suitable for cases where the camera moves while the pictures are taken. Its greatest advantage is the simplicity and efficiency in which it can be implemented. By the use of fast Fourier transforms, the detection of moving objects in a pair of pictures takes about the same computation time as a simple convolution between two pictures of the same size (three Fourier transforms)