Current orthogonal graph drawing algorithms produce drawings which are generally good. However, many times the quality of orthogonal drawings can be significantly improved with a postprocessing technique, called refinement, which improves aesthetic qualities of a drawing such as area, bends, crossings, and total edge length. Refinement is separate from layout and works by analyzing and then fine-tuning the existing drawing in an efficient manner. In this paper we define the problem and goals of orthogonal drawing refinement, review measures of a graph drawing's quality, and introduce a methodology which efficiently refines any orthogonal graph drawing. We have implemented our techniques in C++ and conducted experiments over a set of drawings from five well known orthogonal drawing systems. Experimental analysis shows our techniques to produce an average 37% improvement in area, 23% in bends, 25% in crossings, and 37% in total edge length. Communicated by G. Liotta and S. H. White...
Janet M. Six, Konstantinos G. Kakoulis, Ioannis G.