Digital Signal Processing Reference
In-Depth Information
11.4
Eigenschaften binarer
Bildregionen
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import ij.process.ImageProcessor;
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public class Moments {
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Programm 11.3
Beispiel fur die direkte Berechnung
vonMomenteninJava.DieMetho-
den
moment()
,
centralMoment()
und
normalCentralMoment()
berechnen
fur ein Binarbild die Momente
m
pq
,
µ
pq
bzw.
µ
pq
(Gl. 11.15, 11.20, 11.22).
static final int BACKGROUND = 0;
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static double moment(ImageProcessor ip,int p,int q) {
double Mpq = 0.0;
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for (int v = 0; v < ip.getHeight(); v++) {
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for (int u = 0; u < ip.getWidth(); u++) {
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if (ip.getPixel(u,v) != BACKGROUND) {
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Mpq += Math.pow(u, p) * Math.pow(v, q);
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}
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}
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}
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return Mpq;
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}
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static double centralMoment(ImageProcessor ip,int p,int q)
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{
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double m00 = moment(ip, 0, 0);
// region area
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double xCtr = moment(ip, 1, 0) / m00;
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double yCtr = moment(ip, 0, 1) / m00;
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double cMpq = 0.0;
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for (int v = 0; v < ip.getHeight(); v++) {
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for (int u = 0; u < ip.getWidth(); u++) {
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if (ip.getPixel(u,v) != BACKGROUND) {
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cMpq +=
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Math.pow(u - xCtr, p) *
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Math.pow(v - yCtr, q);
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}
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}
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}
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return cMpq;
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}
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static double normalCentralMoment
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(ImageProcessor ip,int p,int q) {
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double m00 = moment(ip, 0, 0);
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double norm = Math.pow(m00, (double)(p + q + 2) / 2);
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return centralMoment(ip, p, q) / norm;
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}
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}
