/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2012, Geomatys
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotoolkit.image.interpolation;
import org.geotoolkit.image.iterator.PixelIterator;
/**
* Define a standard biCubic interpolation.
*
* @author Rémi Marechal (Geomatys).
*/
public class BiCubicInterpolation1 extends BiCubicInterpolation {
/**
* {@inheritDoc }.
*/
public BiCubicInterpolation1(PixelIterator pixelIterator, ResampleBorderComportement rbc, double[] fillValue) {
super(pixelIterator, rbc, fillValue);
}
/**
* {@inheritDoc }.
*/
public BiCubicInterpolation1(PixelIterator pixelIterator) {
super(pixelIterator);
}
/**
* {@inheritDoc }
*
* Cubic interpolation from 4 values.<br/>
* With always t0 <= t<= t0 + 3 <br/>
* <p>For example : cubic interpolation between 4 pixels.<br/>
*
*
* t = 0 1 2 3<br/>
* f(t) = |f0|f1|f2|f3|<br/>
* In this example t0 = 0.<br/><br/>
*
* Another example :<br/>
* t = -5 -4 -3 -2<br/>
* f(t) = |f0|f1|f2|f3|<br/>
* In this example parameter t0 = -5.</p>
*
* @param t0 f(t0) = f[0].Current position from first pixel interpolation.
* @param t position of interpolation.
* @param f pixel values from t = {0, 1, 2, 3}.
* @return cubic interpolation at t position.
*/
@Override
protected double interpolate1D(double t0, double t, double... f) {
assert (f.length == 4) : "impossible to interpolate with less or more than 4 values";
final double a1 = f[3]/3 - 3*f[2]/2 + 3*f[1] - 11*f[0]/6;
final double a2 = -f[3]/2 + 2*f[2] - 5*f[1]/2 + f[0];
final double a3 = f[3]/6 - f[2]/2 + f[1]/2 - f[0]/6;
final double x = t-t0;
return checkValue(f[0] + (a1 + (a2 + a3*x)*x)*x);
}
}