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ECE516 / CS532 Computer Vision
Pradeep Sen Class 19
ECE 516 / CS 532
Computer Vision
Pradeep Sen
Advanced Graphics Lab
Class 19
ECE516 / CS532 Computer Vision
Pradeep Sen Class 19
Quadrics
Quadrics have 9 degrees of freedom: 10
independent elements of 4x4 symmetric matrix – 1
for scale
Nine points in general position define a quadric
If the matrix Q is singular, then the quadric is
degenerate and may be defined by fewer points
The intersection of a plane and a quadric is a
conic
Transformation of quadric
ECE516 / CS532 Computer Vision
Pradeep Sen Class 19
Quadrics
Projectively equivalent to sphere:
Ruled quadrics:
hyperboloids
of one sheet
hyperboloid
of two sheets paraboloid
sphere ellipsoid
Degenerate ruled quadrics:
cone two planes
source: Hartley and Zisserman