void getCentroid(ImageProcessor ip, int minThreshold, int maxThreshold) {
byte[] pixels = (byte[]) ip.getPixels();
byte[] mask = ip.getMaskArray();
boolean limit = minThreshold > 0 || maxThreshold < 255;
double xsum = 0, ysum = 0;
int count = 0, i, mi, v;
for (int y = ry, my = 0; y < (ry + rh); y++, my++) {
i = y * width + rx;
mi = my * rw;
for (int x = rx; x < (rx + rw); x++) {
if (mask == null || mask[mi++] != 0) {
if (limit) {
v = pixels[i] & 255;
if (v >= minThreshold && v <= maxThreshold) {
count++;
xsum += x;
ysum += y;
}
} else {
count++;
xsum += x;
ysum += y;
}
}
i++;
}
}
xCentroid = xsum / count + 0.5;
yCentroid = ysum / count + 0.5;
if (cal != null) {
xCentroid = cal.getX(xCentroid);
yCentroid = cal.getY(yCentroid, height);
}
}
void calculateMoments(ImageProcessor ip, int minThreshold, int maxThreshold, float[] cTable) {
byte[] pixels = (byte[]) ip.getPixels();
byte[] mask = ip.getMaskArray();
int v, i, mi;
double dv, dv2, sum1 = 0.0, sum2 = 0.0, sum3 = 0.0, sum4 = 0.0, xsum = 0.0, ysum = 0.0;
for (int y = ry, my = 0; y < (ry + rh); y++, my++) {
i = y * width + rx;
mi = my * rw;
for (int x = rx; x < (rx + rw); x++) {
if (mask == null || mask[mi++] != 0) {
v = pixels[i] & 255;
if (v >= minThreshold && v <= maxThreshold) {
dv = ((cTable != null) ? cTable[v] : v) + Double.MIN_VALUE;
dv2 = dv * dv;
sum1 += dv;
sum2 += dv2;
sum3 += dv * dv2;
sum4 += dv2 * dv2;
xsum += x * dv;
ysum += y * dv;
}
}
i++;
}
}
double mean2 = mean * mean;
double variance = sum2 / pixelCount - mean2;
double sDeviation = Math.sqrt(variance);
skewness =
((sum3 - 3.0 * mean * sum2) / pixelCount + 2.0 * mean * mean2) / (variance * sDeviation);
kurtosis =
(((sum4 - 4.0 * mean * sum3 + 6.0 * mean2 * sum2) / pixelCount - 3.0 * mean2 * mean2)
/ (variance * variance)
- 3.0);
xCenterOfMass = xsum / sum1 + 0.5;
yCenterOfMass = ysum / sum1 + 0.5;
if (cal != null) {
xCenterOfMass = cal.getX(xCenterOfMass);
yCenterOfMass = cal.getY(yCenterOfMass, height);
}
}
