Core Concepts
This paper provides a framework and algorithms for the problem of orbital boundary labeling, where labels are placed as circular arcs along the circumference of a circular contour and connected to their feature points using orbital-radial leaders.
Abstract
The paper investigates various problem variants of orbital boundary labeling, which differ in the constraints on the placement of label ports, the order of labels, the size of labels, and the position of ports on the labels.
For the problem variants with free port candidates, the paper presents:
A polynomial-time algorithm for the case with uniform label sizes and uniform port ratios.
NP-hardness results for the case with non-uniform label sizes.
For the problem variants with locked port candidates, the paper presents:
Polynomial-time algorithms for the case with locked label order.
A polynomial-time algorithm for the case with free label order by reducing it to a minimum weight bipartite matching problem.
The paper provides a comprehensive framework to capture the different dimensions of the orbital boundary labeling problem and analyzes the computational complexity of various problem variants.