#include <itkMultivariateLegendrePolynomial.h>
In 2D,
where P_i() denoting a Legendre polynomial of degree i and l it the degree of the polynomial
In 3D,
The size of the parameter vector for 2D is , and for 3D is
To get the size of the parameter vector, users can use one of the two GetNumberOfCoefficients() member functions
To get function result, users can use the operator() or its SimpleForwardIterator's Get() method.
This is a part of the bias correction methods and implemenations that was initially developed and implemented by Martin Styner, Univ. of North Carolina at Chapel Hill, and his colleagues.
For more details. refer to the following articles. "Parametric estimate of intensity inhomogeneities applied to MRI" Martin Styner, G. Gerig, Christian Brechbuehler, Gabor Szekely, IEEE TRANSACTIONS ON MEDICAL IMAGING; 19(3), pp. 153-165, 2000, (http://www.cs.unc.edu/~styner/docs/tmi00.pdf)
"Evaluation of 2D/3D bias correction with 1+1ES-optimization" Martin Styner, Prof. Dr. G. Gerig (IKT, BIWI, ETH Zuerich), TR-197 (http://www.cs.unc.edu/~styner/docs/StynerTR97.pdf)