Patent ID: 7212205

Claim:
A curved surface image processing apparatus for rendering a 3D object on a screen using NURBS data that is shape data of the 3D object, the apparatus comprising: a data transformation unit operable to perform parameter transformation on the NURBS data to transform the NURBS data into rational Bezier control points, the NURBS data forming a NURBS curve and a NURBS surface, and the rational Bezier control points forming a rational Bezier curve and a rational Bezier surface; a curved surface division unit operable to subdivide a rational Bezier surface patch into a plurality of surface patches, the rational Bezier surface patch being made up of the rational Bezier control points transformed by the data transformation unit; and a rendering unit operable to render the 3D object using the plurality of surface patches, wherein the NURBS data includes control points and knot vectors, and the data transformation unit includes: a knot insertion unit operable to perform an operation of inserting knots into the knot vectors using a knot insertion algorithm; and a control point trimming unit operable to delete unnecessary control points in control points that are generated by the operation performed by the knot insertion unit.