Spherical Representations: From EGI to SAI.
Abstract
One of the fundamental problems in representing a curved surface is how to define an intnnsic, i.e., viewer independent, coordinate system over a curved object surface. In order to establish point matching between model and observed feature distributions over the standard coordinate system, we need to set up a coordinate system that maps a point on a curved surface to a point on a standard coordinate system. This mapping should be independent of the viewing direction. Since the boundary of a 3-D object forms a closed surface, a coordinate system defined on the sphere is preferred. We have been exploring several intrinsic mappings from an object surface to a spherical surface. We have investigated several representations including: the EGI (Extended Gaussian Image), the DEGI (Distributed Extended Gaussian Image), the CEGI (Complex Extended Gaussian Image), and the SAl (Spherical Attribute Image). This paper summarizes our motivations to derive each representation and the lessons that we have learned through this endeavor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1995
- Accession Number
- ADA302234
Entities
People
- Katsushi Ikeuchi
- Martial Hebert
Organizations
- Carnegie Mellon University