/* Creates a spline fitted polygon with one pixel segment lengths
that can be retrieved using the getFloatPolygon() method. */
public void fitSplineForStraightening() {
fitSpline((int) getUncalibratedLength() * 2);
if (splinePoints == 0) return;
float[] xpoints = new float[splinePoints * 2];
float[] ypoints = new float[splinePoints * 2];
xpoints[0] = xSpline[0];
ypoints[0] = ySpline[0];
int n = 1, n2;
double inc = 0.01;
double distance = 0.0, distance2 = 0.0, dx = 0.0, dy = 0.0, xinc, yinc;
double x, y, lastx, lasty, x1, y1, x2 = xSpline[0], y2 = ySpline[0];
for (int i = 1; i < splinePoints; i++) {
x1 = x2;
y1 = y2;
x = x1;
y = y1;
x2 = xSpline[i];
y2 = ySpline[i];
dx = x2 - x1;
dy = y2 - y1;
distance = Math.sqrt(dx * dx + dy * dy);
xinc = dx * inc / distance;
yinc = dy * inc / distance;
lastx = xpoints[n - 1];
lasty = ypoints[n - 1];
// n2 = (int)(dx/xinc);
n2 = (int) (distance / inc);
if (splinePoints == 2) n2++;
do {
dx = x - lastx;
dy = y - lasty;
distance2 = Math.sqrt(dx * dx + dy * dy);
// IJ.log(i+" "+IJ.d2s(xinc,5)+" "+IJ.d2s(yinc,5)+" "+IJ.d2s(distance,2)+"
// "+IJ.d2s(distance2,2)+" "+IJ.d2s(x,2)+" "+IJ.d2s(y,2)+" "+IJ.d2s(lastx,2)+"
// "+IJ.d2s(lasty,2)+" "+n+" "+n2);
if (distance2 >= 1.0 - inc / 2.0 && n < xpoints.length - 1) {
xpoints[n] = (float) x;
ypoints[n] = (float) y;
// IJ.log("--- "+IJ.d2s(x,2)+" "+IJ.d2s(y,2)+" "+n);
n++;
lastx = x;
lasty = y;
}
x += xinc;
y += yinc;
} while (--n2 > 0);
}
xSpline = xpoints;
ySpline = ypoints;
splinePoints = n;
}
/**
* Returns the perimeter length of ROIs created using the wand tool and the particle analyzer. The
* algorithm counts edge pixels as 1 and corner pixels as sqrt(2). It does this by calculating the
* total length of the ROI boundary and subtracting 2-sqrt(2) for each non-adjacent corner. For
* example, a 1x1 pixel ROI has a boundary length of 4 and 2 non-adjacent edges so the perimeter
* is 4-2*(2-sqrt(2)). A 2x2 pixel ROI has a boundary length of 8 and 4 non-adjacent edges so the
* perimeter is 8-4*(2-sqrt(2)).
*/
double getTracedPerimeter() {
int sumdx = 0;
int sumdy = 0;
int nCorners = 0;
int dx1 = xp[0] - xp[nPoints - 1];
int dy1 = yp[0] - yp[nPoints - 1];
int side1 = Math.abs(dx1) + Math.abs(dy1); // one of these is 0
boolean corner = false;
int nexti, dx2, dy2, side2;
for (int i = 0; i < nPoints; i++) {
nexti = i + 1;
if (nexti == nPoints) nexti = 0;
dx2 = xp[nexti] - xp[i];
dy2 = yp[nexti] - yp[i];
sumdx += Math.abs(dx1);
sumdy += Math.abs(dy1);
side2 = Math.abs(dx2) + Math.abs(dy2);
if (side1 > 1 || !corner) {
corner = true;
nCorners++;
} else corner = false;
dx1 = dx2;
dy1 = dy2;
side1 = side2;
}
double w = 1.0, h = 1.0;
if (imp != null) {
Calibration cal = imp.getCalibration();
w = cal.pixelWidth;
h = cal.pixelHeight;
}
return sumdx * w + sumdy * h - (nCorners * ((w + h) - Math.sqrt(w * w + h * h)));
}
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);
}
PolygonRoi trimPolygon(PolygonRoi roi, double length) {
int[] x = roi.getXCoordinates();
int[] y = roi.getYCoordinates();
int n = roi.getNCoordinates();
x = smooth(x, n);
y = smooth(y, n);
float[] curvature = getCurvature(x, y, n);
Rectangle r = roi.getBounds();
double threshold = rodbard(length);
// IJ.log("trim: "+length+" "+threshold);
double distance = Math.sqrt((x[1] - x[0]) * (x[1] - x[0]) + (y[1] - y[0]) * (y[1] - y[0]));
x[0] += r.x;
y[0] += r.y;
int i2 = 1;
int x1, y1, x2 = 0, y2 = 0;
for (int i = 1; i < n - 1; i++) {
x1 = x[i];
y1 = y[i];
x2 = x[i + 1];
y2 = y[i + 1];
distance += Math.sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)) + 1;
distance += curvature[i] * 2;
if (distance >= threshold) {
x[i2] = x2 + r.x;
y[i2] = y2 + r.y;
i2++;
distance = 0.0;
}
}
int type = roi.getType() == Roi.FREELINE ? Roi.POLYLINE : Roi.POLYGON;
if (type == Roi.POLYLINE && distance > 0.0) {
x[i2] = x2 + r.x;
y[i2] = y2 + r.y;
i2++;
}
PolygonRoi p = new PolygonRoi(x, y, i2, type);
if (roi.getStroke() != null) p.setStrokeWidth(roi.getStrokeWidth());
p.setStrokeColor(roi.getStrokeColor());
p.setName(roi.getName());
imp.setRoi(p);
return p;
}
PolygonRoi trimFloatPolygon(PolygonRoi roi, double length) {
FloatPolygon poly = roi.getFloatPolygon();
float[] x = poly.xpoints;
float[] y = poly.ypoints;
int n = poly.npoints;
x = smooth(x, n);
y = smooth(y, n);
float[] curvature = getCurvature(x, y, n);
double threshold = rodbard(length);
// IJ.log("trim: "+length+" "+threshold);
double distance = Math.sqrt((x[1] - x[0]) * (x[1] - x[0]) + (y[1] - y[0]) * (y[1] - y[0]));
int i2 = 1;
double x1, y1, x2 = 0, y2 = 0;
for (int i = 1; i < n - 1; i++) {
x1 = x[i];
y1 = y[i];
x2 = x[i + 1];
y2 = y[i + 1];
distance += Math.sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)) + 1;
distance += curvature[i] * 2;
if (distance >= threshold) {
x[i2] = (float) x2;
y[i2] = (float) y2;
i2++;
distance = 0.0;
}
}
int type = roi.getType() == Roi.FREELINE ? Roi.POLYLINE : Roi.POLYGON;
if (type == Roi.POLYLINE && distance > 0.0) {
x[i2] = (float) x2;
y[i2] = (float) y2;
i2++;
}
PolygonRoi p = new PolygonRoi(x, y, i2, type);
if (roi.getStroke() != null) p.setStrokeWidth(roi.getStrokeWidth());
p.setStrokeColor(roi.getStrokeColor());
p.setDrawOffset(roi.getDrawOffset());
p.setName(roi.getName());
imp.setRoi(p);
return p;
}
double getFloatSmoothedPerimeter() {
double length = getSmoothedLineLength();
double w2 = 1.0, h2 = 1.0;
if (imp != null) {
Calibration cal = imp.getCalibration();
w2 = cal.pixelWidth * cal.pixelWidth;
h2 = cal.pixelHeight * cal.pixelHeight;
}
double dx = xpf[nPoints - 1] - xpf[0];
double dy = ypf[nPoints - 1] - ypf[0];
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
return length;
}
double getFloatSmoothedLineLength() {
double length = 0.0;
double w2 = 1.0;
double h2 = 1.0;
double dx, dy;
if (imp != null) {
Calibration cal = imp.getCalibration();
w2 = cal.pixelWidth * cal.pixelWidth;
h2 = cal.pixelHeight * cal.pixelHeight;
}
dx = (xpf[0] + xpf[1] + xpf[2]) / 3.0 - xpf[0];
dy = (ypf[0] + ypf[1] + ypf[2]) / 3.0 - ypf[0];
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
for (int i = 1; i < nPoints - 2; i++) {
dx = (xpf[i + 2] - xpf[i - 1]) / 3.0;
dy = (ypf[i + 2] - ypf[i - 1]) / 3.0;
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
}
dx = xpf[nPoints - 1] - (xpf[nPoints - 3] + xpf[nPoints - 2] + xpf[nPoints - 1]) / 3.0;
dy = ypf[nPoints - 1] - (ypf[nPoints - 3] + ypf[nPoints - 2] + ypf[nPoints - 1]) / 3.0;
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
return length;
}
/** Returns the perimeter (for ROIs) or length (for lines). */
public double getLength() {
if (type == TRACED_ROI) return getTracedPerimeter();
if (nPoints > 2) {
if (type == FREEROI) return getSmoothedPerimeter();
else if (type == FREELINE && !(width == 0 || height == 0)) return getSmoothedLineLength();
}
double length = 0.0;
int dx, dy;
double w2 = 1.0, h2 = 1.0;
if (imp != null) {
Calibration cal = imp.getCalibration();
w2 = cal.pixelWidth * cal.pixelWidth;
h2 = cal.pixelHeight * cal.pixelHeight;
}
if (xSpline != null) {
double fdx, fdy;
for (int i = 0; i < (splinePoints - 1); i++) {
fdx = xSpline[i + 1] - xSpline[i];
fdy = ySpline[i + 1] - ySpline[i];
length += Math.sqrt(fdx * fdx * w2 + fdy * fdy * h2);
}
if (type == POLYGON) {
fdx = xSpline[0] - xSpline[splinePoints - 1];
fdy = ySpline[0] - ySpline[splinePoints - 1];
length += Math.sqrt(fdx * fdx * w2 + fdy * fdy * h2);
}
} else if (xpf != null) {
double fdx, fdy;
for (int i = 0; i < (nPoints - 1); i++) {
fdx = xpf[i + 1] - xpf[i];
fdy = ypf[i + 1] - ypf[i];
length += Math.sqrt(fdx * fdx * w2 + fdy * fdy * h2);
}
if (type == POLYGON) {
fdx = xpf[0] - xpf[nPoints - 1];
fdy = ypf[0] - ypf[nPoints - 1];
length += Math.sqrt(fdx * fdx * w2 + fdy * fdy * h2);
}
} else {
for (int i = 0; i < (nPoints - 1); i++) {
dx = xp[i + 1] - xp[i];
dy = yp[i + 1] - yp[i];
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
}
if (type == POLYGON) {
dx = xp[0] - xp[nPoints - 1];
dy = yp[0] - yp[nPoints - 1];
length += Math.sqrt(dx * dx * w2 + dy * dy * h2);
}
}
return length;
}
float[] getCurvature(float[] x, float[] y, int n) {
float[] x2 = new float[n];
float[] y2 = new float[n];
for (int i = 0; i < n; i++) {
x2[i] = x[i];
y2[i] = y[i];
}
ImageProcessor ipx = new FloatProcessor(n, 1, x, null);
ImageProcessor ipy = new FloatProcessor(n, 1, y, null);
ipx.convolve(kernel, kernel.length, 1);
ipy.convolve(kernel, kernel.length, 1);
float[] indexes = new float[n];
float[] curvature = new float[n];
for (int i = 0; i < n; i++) {
indexes[i] = i;
curvature[i] =
(float) Math.sqrt((x2[i] - x[i]) * (x2[i] - x[i]) + (y2[i] - y[i]) * (y2[i] - y[i]));
}
return curvature;
}
/*
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));
}
