1. Apparatus for scanning a moving object, the apparatus having a sensor oriented to collect a series of images of the object as it passes through a sensor field of view and image processing means arranged to input the series of images and to form a composite image therefrom, the image processing means includes: a) motion estimating means for generating an estimate of object image motion between images in the series of images; and b) display processing means for generating a composite image to which the series of images contributes at positions derived from estimated object image motion.