1. A computer program product comprising instructions for a data processing apparatus to control an apparatus for optically providing information describing an object in motion relative to a field of view, such that the object passes through the field of view, the product tangibly embodied in a non-transitory computer readable medium, the instructions being operable to cause the data processing apparatus to: receive data representing a plurality of one-dimensional images of the field of view, wherein the images are oriented approximately parallel to the direction of motion; and a plurality of the images correspond to a plurality of positions of the object relative to the field of view; and calculate information describing the object based on a plurality of the images.