Edge expression based on tree structure

Abstract It is a difficult problem to construct the edge structure of an object from its defective line drawing after the low-level image processing phase. A tree structure edge expression is proposed, in which the tree expresses the contiguous line segments, and all the trees constitute a forest for the object. Some medium level processing algorithms, such as line connecting, pruning and appending are derived by using the tree structure. Experiments are conducted which show the advantages of the expression and corresponding algorithms.