public GrayLevelClass(ByteProcessor img, boolean first) {
if (!probabilityHistogramDone) {
int[] histogram = img.getHistogram();
probabilityHistogram = new float[256];
for (int i = 0; i < 256; i++) {
probabilityHistogram[i] = ((float) histogram[i]) / ((float) N);
// IJ.write(" "+probabilityHistogram[i]);
}
probabilityHistogramDone = true;
}
if (first) {
index = 1;
omega = probabilityHistogram[index - 1];
if (omega == 0) mu = 0;
else mu = 1 * probabilityHistogram[index - 1] / omega;
} else {
index = 2;
omega = 0;
mu = 0;
for (int i = index; i < 256; i++) {
omega += probabilityHistogram[i - 1];
mu += probabilityHistogram[i - 1] * i;
}
if (omega == 0) mu = 0;
else mu /= omega;
}
}
