Examples with Complex imagingbook.lib.math.Complex used on opensource projects

Example 1 with Complex

use of imagingbook.lib.math.Complex in project imagingbook-common by imagingbook.

the class FourierDescriptor method setCoefficient.

public void setCoefficient(int m, double a, double b) {
    int mm = Arithmetic.mod(m, G.length);
    G[mm] = new Complex(a, b);
}

Example 2 with Complex

use of imagingbook.lib.math.Complex in project imagingbook-common by imagingbook.

the class FourierDescriptor method makeFourierPairsReconstruction.

/**
 * Reconstructs the shape obtained from FD-pairs 0,...,Mp as a polygon (path).
 *
 * @param Mp number of Fourier coefficient pairs
 * @return reconstructed shape
 */
public Path2D makeFourierPairsReconstruction(int Mp) {
    int M = G.length;
    Mp = Math.min(Mp, M / 2);
    int recPoints = Math.max(minReconstructionSamples, G.length * 3);
    Path2D path = new Path2D.Float();
    for (int i = 0; i < recPoints; i++) {
        double t = (double) i / recPoints;
        // assumes that coefficient 0 is never scaled
        Complex pt = new Complex(getCoefficient(0));
        // calculate a particular reconstruction point
        for (int m = 1; m <= Mp; m++) {
            Complex ep = getEllipsePoint(getCoefficient(-m), getCoefficient(m), m, t);
            pt = pt.add(ep.multiply(reconstructionScale));
        }
        double xt = pt.re;
        double yt = pt.im;
        if (i == 0) {
            path.moveTo(xt, yt);
        } else {
            path.lineTo(xt, yt);
        }
    }
    path.closePath();
    return path;
}

Example 3 with Complex

use of imagingbook.lib.math.Complex in project imagingbook-common by imagingbook.

the class FourierDescriptor method makeRotationInvariant.

private double makeRotationInvariant(int Mp) {
    Complex z = new Complex(0, 0);
    for (int m = 1; m <= Mp; m++) {
        Complex Gm = getCoefficient(-m);
        Complex Gp = getCoefficient(+m);
        double w = 1.0 / m;
        z = z.add(Gm.multiply(w));
        z = z.add(Gp.multiply(w));
    }
    double beta = z.arg();
    for (int m = 1; m <= Mp; m++) {
        setCoefficient(-m, getCoefficient(-m).rotate(-beta));
        setCoefficient(m, getCoefficient(m).rotate(-beta));
    }
    return beta;
}

Example 4 with Complex

use of imagingbook.lib.math.Complex in project imagingbook-common by imagingbook.

the class FourierDescriptor method getReconstructionPoint.

/**
 * Reconstructs a single spatial point from this FD using
 * coefficients [mm,...,mp] = [m-,...,m+] at the fractional path position t in [0,1].
 *
 * @param t path position
 * @param mm most negative frequency index
 * @param mp most positive frequency index
 * @return single contour point
 */
private Complex getReconstructionPoint(double t, int mm, int mp) {
    double x = G[0].re;
    double y = G[0].im;
    for (int m = mm; m <= mp; m++) {
        if (m != 0) {
            Complex Gm = getCoefficient(m);
            double A = reconstructionScale * Gm.re;
            double B = reconstructionScale * Gm.im;
            double phi = 2 * Math.PI * m * t;
            double sinPhi = Math.sin(phi);
            double cosPhi = Math.cos(phi);
            x = x + A * cosPhi - B * sinPhi;
            y = y + A * sinPhi + B * cosPhi;
        }
    }
    return new Complex(x, y);
}

Example 5 with Complex

use of imagingbook.lib.math.Complex in project imagingbook-common by imagingbook.

the class FourierDescriptor method makeEllipse.

// -----------------------------------------------------------------------
public Path2D makeEllipse(Complex G1, Complex G2, int m, double xOffset, double yOffset) {
    Path2D path = new Path2D.Float();
    int recPoints = Math.max(minReconstructionSamples, G.length * 3);
    for (int i = 0; i < recPoints; i++) {
        double t = (double) i / recPoints;
        Complex p1 = this.getEllipsePoint(G1, G2, m, t);
        double xt = p1.re;
        double yt = p1.im;
        if (i == 0) {
            path.moveTo(xt + xOffset, yt + yOffset);
        } else {
            path.lineTo(xt + xOffset, yt + yOffset);
        }
    }
    path.closePath();
    return path;
}