Beyond the Simplex: Balanced Prototype Geometry for Scorer-Agnostic Open-Set Recognition

ArXi:2606.01883v1 Announce Type: new Open-set recognition (OSR) requires a classifier to reject inputs from unseen classes which is essential in safety-critical settings such as medical imaging. Simplex based methods, which fix class prototypes at the vertices of a regular simplex and then reject via a distance-ratio score, perform well empirically but lack theoretical justification, and existing analysis applies only when the embedding dimension d is at least C-1, which is the regime in which a regular simplex exists.