1. A method of generating ink data in a device including a position input sensor, the ink data including stroke objects that are vector data configured to reproduce paths formed by operating a pointer, the method comprising: sequentially receiving pen event data detected by the input sensor, the pen event data being indicative of pen down, pen movement, and pen up events; sequentially generating point objects based on coordinate values included in the received pen event data, wherein the point objects serve as control points for interpolating curve segments according to a defined curve interpolation algorithm to form a stroke object; generating a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the stroke object ends; and outputting the start parameter and the end parameter as well as the point objects as part of the stroke object in a defined format.