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3.1 Surface Parametrization

  Consider the set of surfaces and the set of parameter vectors related to them. Each vector has to minimize a given error criterion associated with the surface . A reasonable criterion is the least squared error one. So let's consider the following objective function composed of the sum of error criterions

 

By considering the implicit equation representation of surfaces, a surface is represented by:

where is the measurement vector. Note that any polynomially describable surface can be presented in this scheme, as each component in can be of the form for some .

Given measurements, the least squares criterion related to this equation is

where { represents the sample covariance matrix of the surface . (We assume that the assignment of measurements to surfaces is known.) The objective function ( 1 ) can then be written as :

 

By concatenating all the vectors into one vector equation ( 4 ) can be written as

 



Naoufel Werghi
Thu Jul 10 17:36:04 BST 1997