void handleMouseMove(int sx, int sy) {
// Do rubber banding
int tool = Toolbar.getToolId();
if (!(tool == Toolbar.POLYGON || tool == Toolbar.POLYLINE || tool == Toolbar.ANGLE)) {
imp.deleteRoi();
imp.draw();
return;
}
drawRubberBand(sx, sy);
degrees = Double.NaN;
double len = -1;
if (nPoints > 1) {
double x1, y1, x2, y2;
if (xpf != null) {
x1 = xpf[nPoints - 2];
y1 = ypf[nPoints - 2];
x2 = xpf[nPoints - 1];
y2 = ypf[nPoints - 1];
} else {
x1 = xp[nPoints - 2];
y1 = yp[nPoints - 2];
x2 = xp[nPoints - 1];
y2 = yp[nPoints - 1];
}
degrees =
getAngle(
(int) Math.round(x1),
(int) Math.round(y1),
(int) Math.round(x2),
(int) Math.round(y2));
if (tool != Toolbar.ANGLE) {
Calibration cal = imp.getCalibration();
double pw = cal.pixelWidth, ph = cal.pixelHeight;
if (IJ.altKeyDown()) {
pw = 1.0;
ph = 1.0;
}
len = Math.sqrt((x2 - x1) * pw * (x2 - x1) * pw + (y2 - y1) * ph * (y2 - y1) * ph);
}
}
if (tool == Toolbar.ANGLE) {
if (nPoints == 2) angle1 = degrees;
else if (nPoints == 3) {
double angle2 = getAngle(xp[1], yp[1], xp[2], yp[2]);
degrees = Math.abs(180 - Math.abs(angle1 - angle2));
if (degrees > 180.0) degrees = 360.0 - degrees;
}
}
String length = len != -1 ? ", length=" + IJ.d2s(len) : "";
double degrees2 =
tool == Toolbar.ANGLE && nPoints == 3 && Prefs.reflexAngle ? 360.0 - degrees : degrees;
String angle = !Double.isNaN(degrees) ? ", angle=" + IJ.d2s(degrees2) : "";
int ox = ic != null ? ic.offScreenX(sx) : sx;
int oy = ic != null ? ic.offScreenY(sy) : sy;
IJ.showStatus(imp.getLocationAsString(ox, oy) + length + angle);
}
String getAngleAsString() {
double angle1 = 0.0;
double angle2 = 0.0;
if (xpf != null) {
angle1 = getFloatAngle(xpf[0], ypf[0], xpf[1], ypf[1]);
angle2 = getFloatAngle(xpf[1], ypf[1], xpf[2], ypf[2]);
} else {
angle1 = getFloatAngle(xp[0], yp[0], xp[1], yp[1]);
angle2 = getFloatAngle(xp[1], yp[1], xp[2], yp[2]);
}
degrees = Math.abs(180 - Math.abs(angle1 - angle2));
if (degrees > 180.0) degrees = 360.0 - degrees;
double degrees2 = Prefs.reflexAngle && type == ANGLE ? 360.0 - degrees : degrees;
return ", angle=" + IJ.d2s(degrees2);
}
/*
if selection is closed shape, create a circle with the same area and centroid, otherwise use<br>
the Pratt method to fit a circle to the points that define the line or multi-point selection.<br>
Reference: Pratt V., Direct least-squares fitting of algebraic surfaces", Computer Graphics, Vol. 21, pages 145-152 (1987).<br>
Original code: Nikolai Chernov's MATLAB script for Newton-based Pratt fit.<br>
(http://www.math.uab.edu/~chernov/cl/MATLABcircle.html)<br>
Java version: https://github.com/mdoube/BoneJ/blob/master/src/org/doube/geometry/FitCircle.java<br>
@authors Nikolai Chernov, Michael Doube, Ved Sharma
*/
void fitCircle(ImagePlus imp) {
Roi roi = imp.getRoi();
if (roi == null) {
noRoi("Fit Circle");
return;
}
if (roi.isArea()) { // create circle with the same area and centroid
ImageProcessor ip = imp.getProcessor();
ip.setRoi(roi);
ImageStatistics stats =
ImageStatistics.getStatistics(ip, Measurements.AREA + Measurements.CENTROID, null);
double r = Math.sqrt(stats.pixelCount / Math.PI);
imp.killRoi();
int d = (int) Math.round(2.0 * r);
IJ.makeOval(
(int) Math.round(stats.xCentroid - r), (int) Math.round(stats.yCentroid - r), d, d);
return;
}
Polygon poly = roi.getPolygon();
int n = poly.npoints;
int[] x = poly.xpoints;
int[] y = poly.ypoints;
if (n < 3) {
IJ.error("Fit Circle", "At least 3 points are required to fit a circle.");
return;
}
// calculate point centroid
double sumx = 0, sumy = 0;
for (int i = 0; i < n; i++) {
sumx = sumx + poly.xpoints[i];
sumy = sumy + poly.ypoints[i];
}
double meanx = sumx / n;
double meany = sumy / n;
// calculate moments
double[] X = new double[n], Y = new double[n];
double Mxx = 0, Myy = 0, Mxy = 0, Mxz = 0, Myz = 0, Mzz = 0;
for (int i = 0; i < n; i++) {
X[i] = x[i] - meanx;
Y[i] = y[i] - meany;
double Zi = X[i] * X[i] + Y[i] * Y[i];
Mxy = Mxy + X[i] * Y[i];
Mxx = Mxx + X[i] * X[i];
Myy = Myy + Y[i] * Y[i];
Mxz = Mxz + X[i] * Zi;
Myz = Myz + Y[i] * Zi;
Mzz = Mzz + Zi * Zi;
}
Mxx = Mxx / n;
Myy = Myy / n;
Mxy = Mxy / n;
Mxz = Mxz / n;
Myz = Myz / n;
Mzz = Mzz / n;
// calculate the coefficients of the characteristic polynomial
double Mz = Mxx + Myy;
double Cov_xy = Mxx * Myy - Mxy * Mxy;
double Mxz2 = Mxz * Mxz;
double Myz2 = Myz * Myz;
double A2 = 4 * Cov_xy - 3 * Mz * Mz - Mzz;
double A1 = Mzz * Mz + 4 * Cov_xy * Mz - Mxz2 - Myz2 - Mz * Mz * Mz;
double A0 = Mxz2 * Myy + Myz2 * Mxx - Mzz * Cov_xy - 2 * Mxz * Myz * Mxy + Mz * Mz * Cov_xy;
double A22 = A2 + A2;
double epsilon = 1e-12;
double ynew = 1e+20;
int IterMax = 20;
double xnew = 0;
int iterations = 0;
// Newton's method starting at x=0
for (int iter = 1; iter <= IterMax; iter++) {
iterations = iter;
double yold = ynew;
ynew = A0 + xnew * (A1 + xnew * (A2 + 4. * xnew * xnew));
if (Math.abs(ynew) > Math.abs(yold)) {
if (IJ.debugMode) IJ.log("Fit Circle: wrong direction: |ynew| > |yold|");
xnew = 0;
break;
}
double Dy = A1 + xnew * (A22 + 16 * xnew * xnew);
double xold = xnew;
xnew = xold - ynew / Dy;
if (Math.abs((xnew - xold) / xnew) < epsilon) break;
if (iter >= IterMax) {
if (IJ.debugMode) IJ.log("Fit Circle: will not converge");
xnew = 0;
}
if (xnew < 0) {
if (IJ.debugMode) IJ.log("Fit Circle: negative root: x = " + xnew);
xnew = 0;
}
}
if (IJ.debugMode)
IJ.log("Fit Circle: n=" + n + ", xnew=" + IJ.d2s(xnew, 2) + ", iterations=" + iterations);
// calculate the circle parameters
double DET = xnew * xnew - xnew * Mz + Cov_xy;
double CenterX = (Mxz * (Myy - xnew) - Myz * Mxy) / (2 * DET);
double CenterY = (Myz * (Mxx - xnew) - Mxz * Mxy) / (2 * DET);
double radius = Math.sqrt(CenterX * CenterX + CenterY * CenterY + Mz + 2 * xnew);
if (Double.isNaN(radius)) {
IJ.error("Fit Circle", "Points are collinear.");
return;
}
CenterX = CenterX + meanx;
CenterY = CenterY + meany;
imp.killRoi();
IJ.makeOval(
(int) Math.round(CenterX - radius),
(int) Math.round(CenterY - radius),
(int) Math.round(2 * radius),
(int) Math.round(2 * radius));
}