/*
Copyright 2018 Lingqi Yan
This file is part of WaveOpticsBrdf.
WaveOpticsBrdf is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
WaveOpticsBrdf is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with WaveOpticsBrdf. If not, see <https://www.gnu.org/licenses/>.
*/
#include "gaborkernel.h"
comp GaborKernel::eval(Vector2 s) {
return C * G(s, mu, sigma) * cnis(Float(2.0 * M_PI * a.dot(s)));
}
comp GaborKernel::xform(Vector2 u) {
Float sigmaPrime = Float(1.0 / (2.0 * M_PI * sigma));
comp CPrime = C * Float(1.0 / (2.0 * M_PI * sigma * sigma)) * cnis(Float(2.0 * M_PI * a.dot(mu)));
GaborKernel g(-a, sigmaPrime, mu, CPrime);
return g.eval(u);
}
GaborKernel GaborKernelPrime::toGaborKernel(Float lambda) {
Float l = sigma * SCALE_FACTOR;
comp C = l * l * cnis(4.0 * M_PI / lambda * cInfo);
Vector2 a = aInfo / lambda;
return GaborKernel(mu, sigma, a, C);
}
Vector2 GaborKernelPrime::getFFTCenter(Float lambda) {
return -aInfo / lambda;
}
Float GaborKernelPrime::getFFTWidth() {
return 1.0 / (2.0 * M_PI * sigma);
}