The Hyperbolic Geometry of Illumination-Induced Chromaticity Changes

The non-negativity of color signals implies that they span a conical space with a hyperbolic geometry. We use perspective projections to separate intensity from chromaticity, and for 3-D color descriptors the chromatic properties are represented by points on the unit disk. Descriptors derived from the same object point but under different imaging conditions can be joined by a hyperbolic geodesic. The properties of this model are investigated using multichannel images of natural scenes and black body illuminants of different temperatures. We show, over a series of static scenes with different illuminants, how illumination changes influence the hyperbolic distances and the geodesics. Descriptors derived from conventional RGB images are also addressed.

• Type: Conference
• Year: 2007
• Where: CVPR
• Authors: Reiner Lenz, Pedro Latorre Carmona, Peter Meer
• Keywords: 3-d Color Descriptors, Black Body Illuminants, Computer Vision, CVPR 2007, Hyperbolic Distances, Hyperbolic Geodesic, Hyperbolic Geometry