Fast and Exact Visibility on Digitized Shapes and Application to Saliency-Aware Normal Estimation

Computing visibility on a geometric object requires heavy computations since it requires to identify pairs of points that are visible to each other, i.e. there is a straight segment joining them that stays in the close vicinity of the object boundary. We propose to exploit a specific representation of digital sets based on lists of integral intervals in order to compute efficiently the complete visibility graph between lattice points of the digital shape. As a quite direct application, we show then how we can use visibility to estimate the normal vector field of a digital shape in an accurate and convergent manner while staying aware of the salient and sharp features of the shape.

Discrete Geometry and Mathematical Morphology - 4th International Joint Conference, {DGMM} 2025, Groningen, The Netherlands, November 3-6, 2025, Proceedings, volume 16296 of Lecture Notes in Computer Science, pp 31-43, 2025. Springer