Semi-Local Invariants

Ehud Rivlin and Isaac Weiss.
Semi-Local Invariants.
In CVPR93, 697-698, 1993

Abstract

Geometric invariants are shape descriptors that remain unchanged under geometric transformations such as projection, or change of the viewpoint. In [2] we developed a new method of obtaining local projective and affine invariants for a general curve without any correspondences. Being local, the invariants are much less sensitive to occlusion than global invariants. The invariants computation is based on a canonical method. This consists of defining a canonical coordinate system using intrinsic properties of the shape, independently of the given coordinate system. Since this canonical system is independent of the original one, it is invariant and all quantities defined in it arc invariant. Here we present a further development of the method to obtain local semi-invariants, that is local invariants for curves with known correspondences. Several configurations are treated: curves with known correspondences of one or two feature points or lines.

Bibtex Entry

@inproceedings{RivlinW93i,
title = {Semi-Local Invariants},
author = {Ehud Rivlin and Isaac Weiss},
year = {1993},
booktitle = {CVPR93},
pages = {697-698},
abstract = {Geometric invariants are shape descriptors that remain unchanged under geometric transformations such as projection, or change of the viewpoint. In [2] we developed a new method of obtaining local projective and affine invariants for a general curve without any correspondences. Being local, the invariants are much less sensitive to occlusion than global invariants. The invariants computation is based on a canonical method. This consists of defining a canonical coordinate system using intrinsic properties of the shape, independently of the given coordinate system. Since this canonical system is independent of the original one, it is invariant and all quantities defined in it arc invariant. Here we present a further development of the method to obtain local semi-invariants, that is local invariants for curves with known correspondences. Several configurations are treated: curves with known correspondences of one or two feature points or lines.}
}