/**
* Locate ellipses within an image
*
* @param grayImage Grayscale image
* @return Ellipse locations
*/
public EllipseLocationResult locateEllipses(Mat grayImage) {
Mat gray = grayImage.clone();
Filter.downsample(gray, 2);
Filter.upsample(gray, 2);
Imgproc.Canny(gray, gray, 5, 75, 3, true);
Filter.dilate(gray, 2);
Mat cacheHierarchy = new Mat();
List<MatOfPoint> contoursTemp = new ArrayList<>();
// Find contours - the parameters here are very important to compression and retention
Imgproc.findContours(
gray, contoursTemp, cacheHierarchy, Imgproc.CV_RETR_TREE, Imgproc.CHAIN_APPROX_TC89_KCOS);
// List contours
List<Contour> contours = new ArrayList<>();
for (MatOfPoint co : contoursTemp) {
contours.add(new Contour(co));
}
// Find ellipses by finding fit
List<Ellipse> ellipses = new ArrayList<>();
for (MatOfPoint co : contoursTemp) {
contours.add(new Contour(co));
// Contour must have at least 6 points for fitEllipse
if (co.toArray().length < 6) continue;
// Copy MatOfPoint to MatOfPoint2f
MatOfPoint2f matOfPoint2f = new MatOfPoint2f(co.toArray());
// Fit an ellipse to the current contour
Ellipse ellipse = new Ellipse(Imgproc.fitEllipse(matOfPoint2f));
// Draw ellipse
ellipses.add(ellipse);
}
return new EllipseLocationResult(contours, ellipses);
}
public static void Circle(List<MatOfPoint> contours, int index) {
int i = index;
Mat mRGBA = new Mat();
Utils.bitmapToMat(image, mRGBA);
// cyklus s podmienkou na konci
do {
int buff[] = new int[4];
hierarchy.get(0, i, buff);
// Get contour form list
Mat contour = contours.get(i);
// id kont�ry
int id = i;
// dostaneme �a��ie id kont�ry
i = buff[0];
// zis�ujeme �i m�me dostato�ne ve�k� kont�ru aby sme sa �ou v�bec zaoberali
if (Imgproc.contourArea(contour) > 500) {
List<Point> points = new ArrayList<Point>();
// dostaneme celkov� po�et kont�r
int num = (int) contour.total();
// vytvor�me si pole o dvojn�sobnej ve�kosti samotnej kontury
int temp[] = new int[num * 2];
// na��tame si kont�ru do do�asnej premennej
contour.get(0, 0, temp);
// konvertujeme List<Point> do MatOfPoint2f pre pou�itie fitEllipse
for (int j = 0; j < num * 2; j = j + 2) {
points.add(new Point(temp[j], temp[j + 1]));
}
MatOfPoint2f specialPointMtx = new MatOfPoint2f(points.toArray(new Point[0]));
// do premennej bound uklad�me dokonal� elipsu
RotatedRect bound = Imgproc.fitEllipse(specialPointMtx);
// Vypo��ta sa hodnota pi
double pi =
Imgproc.contourArea(contour) / ((bound.size.height / 2) * (bound.size.width / 2));
// zis�ujeme toleranciu pi - zaoplenie
if (Math.abs(pi - 3.14) > 0.03) {
int k = buff[2];
// zis�ujeme �i existuje nejak� rodi� kont�ry
if (k != -1) {
Circle(contours, k);
}
continue;
}
// konvertujeme MatOfPoint2f do MatOfPoint pre funckiu fitEllipse - rozdie� je len v 32-bit
// float a 32-bit int
MatOfPoint NewMtx = new MatOfPoint(specialPointMtx.toArray());
// dostaneme s�radnice najmen�ieho mo�n�ho �tvorca
Rect box = Imgproc.boundingRect(NewMtx);
// nacita obrazok znova
Mat mat_for_count = new Mat();
Utils.bitmapToMat(image, mat_for_count);
// vytvori sa klon stvorca - dobry kandidat pre vyhladanie
Mat candidate = ((mat_for_count).submat(box)).clone();
// napln maticu binarnou ciernou
Mat mask = new Mat(box.size(), candidate.type(), new Scalar(0, 0, 0));
// naplni ciernu plochu bielimi konturami
Imgproc.drawContours(
mask,
contours,
id,
new Scalar(255, 255, 255),
-1,
8,
hierarchy,
0,
new Point(-box.x, -box.y));
// ulozi sa kandidat
Mat roi = new Mat(candidate.size(), candidate.type(), new Scalar(255, 255, 255));
// ulozia sa len informacie o kandidatovi
candidate.copyTo(roi, mask);
double longAxis;
double shortAxis;
// ziska dve osy elipsy
if (bound.size.height < bound.size.width) {
shortAxis = bound.size.height / 2;
longAxis = bound.size.width / 2;
} else {
shortAxis = bound.size.width / 2;
longAxis = bound.size.height / 2;
}
// zastavi sa vyhladavanie pokial je elipsa prilis ovalna
if ((longAxis / shortAxis) < 2.0) {
signList.add(roi);
boxList.add(box);
}
}
// zis�uje sa �i je tam e�te �al�� kandid�t
} while (i != -1);
}