1. A method of generating, from primitive data comprising geometric and surface descriptions of a plurality of image primitives, an image of objects in a three dimensional space constituted by a regular, two dimensional filtered pixel array having two principal axes, the method comprising: using the primitive data to form N renditions comprising respective N intermediate pixel arrays obtained by imposing respective N different offsets between the primitives and a sample point for each pixel of said filtered pixel array, said N different offsets defining a basic array of N sample points distributed substantially over the area of a pixel of said filtered pixel array, which basic array of N sample points is applicable to each pixel of said filtered pixel array; and combining the N intermediate pixel arrays to generate said filtered pixel array constituting an image which has been oversampled and filtered; wherein the N offsets are obtained by: selecting a class of image feature for filtering; and determining the locations of the N sample points of the basic array in dependence upon the selected class of image feature so as to ensure substantially N times oversampling of the selected class of image feature; wherein the selected class of image feature comprises edges, which are nearly aligned with one or the other of the principal axes of the filtered pixel array, the locations of the N sample points in the basic array being chosen so as to divide the area of a pixel of the filtered pixel array at substantially N places in the direction of at least one of the principal axes of the filtered pixel array.