A three-dimensional computer graphics image generator has an image input unit for inputting an image of a 3-D object into the CG image generator; a display unit for displaying the input image; a characteristic point indication unit for externally specifying characteristic points on the displayed image; and a 3-D object recognition unit for providing 3-D data according to the characteristic-point-added input image. According to the 3-D data, the 3-D CG image generator provides a 3-D CG image that faithfully represents the object.