A new approach to discrete conical curves

Conics drawing is an important issue in image processing and CAD. Many methods exist, but few are based on linear iterative methods X/sub n+1/ = SX/sub n/ for the computation of points belonging to a conic with equation X/sup T/CX = z. This paper studies these methods in a systematic way. It shows that S and C are linked by S = /spl plusmn/exp(/spl theta/JC), where J is the /spl pi//2 rotation matrix and /spl theta/ controls the points' density. Different linear properties are established, especially a bijective connection with simple processes on the unit circle or unit hyperbola. Moreover, an efficient drawing algorithm for elliptic and hyperbolic arcs is derived.