1. A method for tracking a first object across a number of images, the method comprising: obtaining and storing an exemplar view for the first object and an associated appearance model thereof in a first image; forming, in association with a second image, an adjusted colour appearance model of the first object based on the associated appearance model of the first object and an appearance model of at least one second object which is located within a predetermined distance from the first object; determining a scale and centroid adjustment of the exemplar view based on the adjusted colour appearance model; applying tracking to the first object in the second image to determine a position of the first object in the second image; and correcting the position of the first object in the second image according to the determined scale and centroid adjustment.