Projectice subgroups for grouping
Luc J. Van Gool · Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences · 1998
The history of grouping in computer vision stretches a long way back. One strand could be called geometry–based and focuses on shapes with special regularities such as symmetry. From a mathematical point of view, the subparts of such shapes are related by special transformations. The presented work proposes to systematically classify such ‘special’ transformations by studying projective subgroups that come with fixed structures. These are geometric entities such as points or lines that remain fixed under the projectivities in the subgroups. As subgroups have their own invariants, these can then be used to guide the search for the corresponding groupings.