This paper proposes an error analysis of reparametrization based approaches for planar curve offsetting. The approximation error in Hausdorff distance is computed. The error is bounded by O(r sin(2) beta), where r is the offset radius and beta is the angle deviation of a difference vector from the normal vector. From the error bound an interesting geometric property of the approach is observed: when the original curve is offset in its convex side, the approximate offset curve always lies in the
