Abstract: A method for filling a closed region. The closed region is enclosed by a contour according to a plurality of edge points. First, generate a path linked list. The path linked list includes a plurality of nodes for recording the edge points and the intermediate points between the edge points on the contour. Next, generate a filling array linked list. The filling array linked list records a plurality of filling line segment. The two end points of each of the line segments are on the contour, and each of the line segments is in the closed region. Then, fill the closed region according to the line segments.