Patent ID: 6577991
Filing Date: 2003-06-10
Classification: G06T

Abstract:
A method of processing a figure for obtaining an enlarged figure or a reduced figure by moving the sides of a polygon, which is composed by putting a plurality of horizontal trapezoids upon each other, each of the trapezoids having upper and lower sides parallel to an X-axis, in the direction of a Y-axis to the outside or inside of the polygon in parallel with each other,the method of processing a figure comprising the steps of: selecting horizontal trapezoids one by one along Y axis out of the plurality of horizontal trapezoids as an objective horizontal trapezoid; extracting a first group of segments included in the sides composing the objective horizontal trapezoid and also composing the sides of the polygon, also extracting a second group of segments included in an upper side and right and left sides of a lower horizontal trapezoid and composing the sides of the polygon if there is such a lower horizontal trapezoid coming into contact with the lower side of the objective horizontal trapezoid, also extracting a third group of segments included in the side of an upper horizontal trapezoid which is a side coming into contact with the objective horizontal trapezoid and composing the sides of the polygon if there is such an upper horizontal trapezoid coming into contact with an upper side of the objective horizontal trapezoid; creating a new first group of segments, a new second group of segments and a new third group of segments, if the first group of segments, the second group of segments and the third group of segments are respectively moved to the outside or inside of the polygon in parallel with each other and also if an extension line located outside the polygon or a segment after the completion of movement is removed on the basis of an intersection point of the extension line of the segment composing each group of segments which has been moved in parallel or on the basis of an intersection, point of the segment composing each group of segments which has been moved in parallel; removing the new third group of segments after the intersection point of the new first group of segments and the new second group of segments and the intersection point of the new first group of segments and the new third group of segments are stored as contact points and also removing the new second group of segments on the lower side of a division point if the predetermined division point exists on the new second group of segments; sorting the contact point and the division point in the order of the Y coordinate value and the X coordinate value under the condition that priority is given to Y coordinate value; drawing parallel lines parallel to the X-axis from the contact point and the division point in the order of sorting to the inside of the polygon while it is detected whether or not points of intersection exist between the new second group of segments and the parallel line or between the new first group of segments and the parallel line and also making a horizontal trapezoid encircled by the parallel line, the new first group of segments and the new second group of segments to be a new horizontal trapezoid composing the enlarged figure or the reduced figure if the points of intersection exist; and storing the contact point and the point of intersection included in the parallel line, the Y-coordinate value of which is the highest in the parallel line on which the point of intersection exists, instead of the division point if the upper horizontal trapezoid exists.