Boundary Labelling of Optimal Total Leader Length

In this paper, we consider the leader length minimization problem for boundary labelling, i.e. the problem of finding a legal leaderlabel placement, such that the total leader length is minimized. We present an O(nlogn) algorithm assuming type-opo leaders (rectilinear lines with either zero or two bends) and labels of uniform size which can be attached to all four sides of rectangle R. Our algorithm supports fixed and sliding ports, i.e., the point where each leader is connected to the label (referred to as port) may be fixed or may slide along a label edge.