1. A graphic processing method in which a figure concerning a shape of an object is processed by an image, comprising: calculating a first figure skeleton apart from an outline of the figure by each equal distance in a central direction of the figure using at least one of a medial axis and a chordal axis with respect to a figure which represents the outline of the object shape reflected in a digital image by a set of points; removing branch lines from a vertex of the figure to the skeleton in the calculated first figure skeleton to obtain a second figure skeleton; and defining a curve coordinate system in which the second figure skeleton is one coordinate axis and a distance between the second figure skeleton and the outline of the figure is the other coordinate axis with respect to data obtained by one circulation of the outline of the figure using one end point of the second figure skeleton as a start point and using the other end point as a terminal point to transform the coordinate of points on the outline of the figure into the other coordinate axis of the curve coordinate system.