CamLiveRetriever.java

package org.genericsystem.cv.classifier;

import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.function.Predicate;
import java.util.stream.Collectors;

import javafx.scene.image.ImageView;
import javafx.scene.layout.GridPane;

import org.genericsystem.cv.AbstractApp;
import org.genericsystem.cv.Calibrated.AngleCalibrated;
import org.genericsystem.cv.Img;
import org.genericsystem.cv.lm.LMHostImpl;
import org.genericsystem.cv.utils.Line;
import org.genericsystem.cv.utils.NativeLibraryLoader;
import org.genericsystem.cv.utils.Tools;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import org.opencv.videoio.VideoCapture;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@SuppressWarnings({ "resource" })
public class CamLiveRetriever extends AbstractApp {

	static {
		NativeLibraryLoader.load();
	}

	static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

	private static long counter = 0;

	private static final int STABILIZATION_DELAY = 500;
	private static final int FRAME_DELAY = 100;

	private final ScheduledExecutorService timerFields = new ScheduledThreadPoolExecutor(1, new ThreadPoolExecutor.DiscardPolicy());
	private final VideoCapture capture = new VideoCapture(0);
	private final Fields fields = new Fields();

	private ImgDescriptor stabilizedImgDescriptor;
	private Mat frame = new Mat();
	private boolean stabilizationHasChanged = true;
	private int stabilizationErrors = 0;
	private Point vp = new Point(0, 0);
	private AngleCalibrated calibrated;

	public static void main(String[] args) {
		launch(args);
	}

	@Override
	public void stop() throws Exception {
		super.stop();
		timerFields.shutdown();
		timerFields.awaitTermination(5, TimeUnit.SECONDS);
	}

	@Override
	protected void fillGrid(GridPane mainGrid) {

		capture.read(frame);

		ImageView src0 = new ImageView(Tools.mat2jfxImage(frame));
		mainGrid.add(src0, 0, 0);

		ImageView src1 = new ImageView(Tools.mat2jfxImage(frame));
		mainGrid.add(src1, 1, 0);

		timerFields.scheduleAtFixedRate(() -> onSpace(), 0, STABILIZATION_DELAY, TimeUnit.MILLISECONDS);

		AngleCalibrated.calibrate(frame.width(), frame.height());
		calibrated = new AngleCalibrated(vp);
		// Detect the rectangles
		timerFields.scheduleAtFixedRate(() -> {
			try {
				Stats.beginTask("frame");
				capture.read(frame);
				if (frame == null) {
					logger.warn("No frame !");
					return;
				}

				Mat deperspectivGraphy = computeFrameToDeperspectivedHomography(frame);
				if (deperspectivGraphy == null) {
					logger.warn("Unable to compute a valid deperspectivation");
					return;
				}
				if (stabilizationErrors > 20) {
					// TODO: clean fields
				fields.reset();
				stabilizationErrors = 0;
				stabilizedImgDescriptor = null;
			}
			if (stabilizedImgDescriptor == null) {
				stabilizedImgDescriptor = new ImgDescriptor(frame, deperspectivGraphy);
				return;
			}
			ImgDescriptor newImgDescriptor = new ImgDescriptor(frame, deperspectivGraphy);
			Mat stabilizationHomography = stabilizedImgDescriptor.computeStabilizationGraphy(newImgDescriptor);
			if (stabilizationHomography == null) {
				stabilizationErrors++;
				logger.warn("Unable to compute a valid stabilization ({} times)", stabilizationErrors);
				return;
			}
			Img stabilized = warpPerspective(frame, stabilizationHomography);
			Img stabilizedDisplay = new Img(stabilized.getSrc(), true);
			if (stabilizationHasChanged) {
				Stats.beginTask("stabilizationHasChanged");
				Mat fieldsHomography = new Mat();
				stabilized = newImgDescriptor.getDeperspectivedImg();
				stabilizedDisplay = new Img(stabilized.getSrc(), true);
				Core.gemm(deperspectivGraphy, stabilizationHomography.inv(), 1, new Mat(), 0, fieldsHomography);
				Stats.beginTask("restabilizeFields");
				fields.restabilizeFields(fieldsHomography);
				Stats.endTask("restabilizeFields");
				Stats.beginTask("merge fields");
				fields.merge(detectRects(stabilizedDisplay));
				Stats.endTask("merge fields");

				fields.removeOverlaps();

				final Img stabilizedDisplay_ = stabilizedDisplay;
				fields.stream().filter(f -> f.getDeadCounter() == 0).forEach(f -> f.draw(stabilizedDisplay_, f.getDeadCounter() == 0 ? new Scalar(0, 255, 0) : new Scalar(0, 0, 255)));

				stabilizedImgDescriptor = newImgDescriptor;
				stabilizationHomography = deperspectivGraphy;
				stabilizationHasChanged = false;
				Stats.endTask("stabilizationHasChanged");
			}
			Img display = new Img(frame, false);

			Stats.beginTask("consolidateOcr");
			fields.performOcr(stabilized);
			Stats.endTask("consolidateOcr");
			fields.drawOcrPerspectiveInverse(display, stabilizationHomography.inv(), new Scalar(0, 255, 0), 1);

			fields.drawIndestructible(display, stabilizationHomography.inv());

			src0.setImage(display.toJfxImage());
			src1.setImage(stabilizedDisplay.toJfxImage());
			Stats.endTask("frame");

			Stats.resetCumulative("RANSAC re-compute");
			if (++counter % 10 == 0) {
				System.out.println(Stats.getStatsAndReset());
				counter = 0;
			}
		} catch (Throwable e) {
			logger.warn("Exception while computing layout.", e);
		}
	}, 50, FRAME_DELAY, TimeUnit.MILLISECONDS);

	}

	@Override
	protected void onSpace() {
		stabilizationHasChanged = true;
	}

	private List<Rect> detectRects(Img stabilized) {
		Img closed = stabilized.bilateralFilter(10, 80, 80).adaptativeGaussianInvThreshold(11, 3).morphologyEx(Imgproc.MORPH_CLOSE, Imgproc.MORPH_RECT, new Size(11, 3));
		List<MatOfPoint> contours = new ArrayList<>();
		Imgproc.findContours(closed.getSrc(), contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
		double minArea = 200;
		List<Rect> res = contours.stream().filter(contour -> Imgproc.contourArea(contour) > minArea).map(c -> Imgproc.boundingRect(c)).collect(Collectors.toList());
		res.forEach(rect -> Imgproc.rectangle(stabilized.getSrc(), rect.tl(), rect.br(), new Scalar(255, 200, 0)));
		return res;
	}

	static Img warpPerspective(Mat frame, Mat homography) {
		Mat dePerspectived = new Mat(frame.size(), CvType.CV_8UC3, Scalar.all(255));
		Imgproc.warpPerspective(frame, dePerspectived, homography, frame.size(), Imgproc.INTER_LINEAR, Core.BORDER_REPLICATE, Scalar.all(255));
		return new Img(dePerspectived, false);
	}

	private Lines houghlinesP(Mat frame) {
		Img grad = new Img(frame, false).morphologyEx(Imgproc.MORPH_GRADIENT, Imgproc.MORPH_RECT, new Size(2, 2)).otsu().morphologyEx(Imgproc.MORPH_CLOSE, Imgproc.MORPH_ELLIPSE, new Size(3, 3));
		return new Lines(grad.houghLinesP(1, Math.PI / 180, 10, 100, 10));
	}

	private Mat computeFrameToDeperspectivedHomography(Mat frame) {
		Lines lines = houghlinesP(frame);
		if (lines.size() > 10) {
			lines = lines.reduce(20);
			// lines.draw(frame, new Scalar(0, 0, 255));
			lines = lines.filter(line -> distance(vp, line) < 0.48);
			// lines.draw(frame, new Scalar(0, 255, 0));
			lines = lines.reduce(10);
			Stats.beginTask("ransac");
			double[] newThetaPhi = new LMHostImpl<>((line, params) -> distance(new AngleCalibrated(params).uncalibrate(), line), lines.lines, calibrated.getTethaPhi()).getParams();
			calibrated = calibrated.dump(newThetaPhi, 1);
			vp = calibrated.uncalibrate();
			Stats.endTask("ransac");
			// System.out.println("Vanishing point : " + vp);
			return findHomography(vp, frame.width(), frame.height());
		} else {
			System.out.println("Not enough lines : " + lines.size());
			return null;
		}

		// Stats.beginTask("ransac");
		// Ransac<Line> ransac = lines.vanishingPointRansac(frame.width(), frame.height());
		// Stats.endTask("ransac");
		// Mat vpMat = (Mat) ransac.getBestModel().getParams()[0];
		// Point vp = new Point(vpMat.get(0, 0)[0], vpMat.get(1, 0)[0]);
		// return findHomography(vp, frame.width(), frame.height());
	}

	private double distance(Point vp, Line line) {
		double[] lineSegment = getNormalizedLine(line);
		double n0 = -lineSegment[1];
		double n1 = lineSegment[0];
		double nNorm = Math.sqrt(n0 * n0 + n1 * n1);
		double[] midPoint = getMiLine(line);
		double r0, r1;
		r0 = vp.y * midPoint[2] - midPoint[1];
		r1 = midPoint[0] - vp.x * midPoint[2];
		double rNorm = Math.sqrt(r0 * r0 + r1 * r1);
		double num = (r0 * n0 + r1 * n1);
		if (num < 0)
			num = -num;

		double d = 0;
		if (nNorm != 0 && rNorm != 0)
			d = num / (nNorm * rNorm);
		// d *= line.size();
		return d;
	}

	private double[] getNormalizedLine(Line line) {
		double a = line.y1 - line.y2;
		double b = line.x2 - line.x1;
		double c = line.y1 * line.x2 - line.x1 * line.y2;
		double norm = Math.sqrt(a * a + b * b + c * c);
		return new double[] { a / norm, b / norm, c / norm };
	}

	private double[] getMiLine(Line line) {
		return new double[] { (line.x1 + line.x2) / 2, (line.y1 + line.y2) / 2, 1d };
	}

	private Mat findHomography(Point vp, double width, double height) {
		Point bary = new Point(width / 2, height / 2);
		double alpha_ = Math.atan2((vp.y - bary.y), (vp.x - bary.x));
		if (alpha_ < -Math.PI / 2 && alpha_ > -Math.PI)
			alpha_ = alpha_ + Math.PI;
		if (alpha_ < Math.PI && alpha_ > Math.PI / 2)
			alpha_ = alpha_ - Math.PI;
		double alpha = alpha_;

		Point rotatedVp = rotate(bary, alpha, vp)[0];

		Point A = new Point(0, 0);
		Point B = new Point(width, 0);
		Point C = new Point(width, height);
		Point D = new Point(0, height);

		Point AB2 = new Point(width / 2, 0);
		Point CD2 = new Point(width / 2, height);

		Point A_, B_, C_, D_;
		if (rotatedVp.x >= width / 2) {
			A_ = new Line(AB2, rotatedVp).intersection(0);
			D_ = new Line(CD2, rotatedVp).intersection(0);
			C_ = new Line(A_, bary).intersection(new Line(CD2, rotatedVp));
			B_ = new Line(D_, bary).intersection(new Line(AB2, rotatedVp));
		} else {
			B_ = new Line(AB2, rotatedVp).intersection(width);
			C_ = new Line(CD2, rotatedVp).intersection(width);
			A_ = new Line(C_, bary).intersection(new Line(AB2, rotatedVp));
			D_ = new Line(B_, bary).intersection(new Line(CD2, rotatedVp));
		}

		// System.out.println("vp : " + vp);
		// System.out.println("rotated vp : " + rotatedVp);
		// System.out.println("Alpha : " + alpha * 180 / Math.PI);
		// System.out.println();
		// System.out.println("A : " + A + " " + A_);
		// System.out.println("B : " + B + " " + B_);
		// System.out.println("C : " + C + " " + C_);
		// System.out.println("D : " + D + " " + D_);

		Mat src = new MatOfPoint2f(rotate(bary, -alpha, A_, B_, C_, D_));
		Mat dst = new MatOfPoint2f(A, B, C, D);
		return Imgproc.getPerspectiveTransform(src, dst);
	}

	private Point[] rotate(Point bary, double alpha, Point... p) {
		Mat matrix = Imgproc.getRotationMatrix2D(bary, alpha / Math.PI * 180, 1);
		MatOfPoint2f points = new MatOfPoint2f(p);
		MatOfPoint2f results = new MatOfPoint2f();
		Core.transform(points, results, matrix);
		return results.toArray();
	}

	public static class Lines extends org.genericsystem.cv.utils.Lines {
		private static Mat K;

		public Lines(Mat src) {
			super(src);
		}

		public Lines(Collection<Line> lines) {
			super(lines);
		}

		public static Lines of(Collection<Line> lines) {
			return new Lines(lines);
		}

		public Lines filter(Predicate<Line> predicate) {
			return new Lines(lines.stream().filter(predicate).collect(Collectors.toList()));
		}

		public Lines reduce(int max) {
			if (lines.size() <= max)
				return this;
			Set<Line> newLines = new HashSet<>();
			while (newLines.size() < max)
				newLines.add(lines.get((int) (Math.random() * size())));
			return new Lines((newLines));
		}

		// private Mat getLineMat(Line line) {
		// Mat a = new Mat(3, 1, CvType.CV_32F);
		// Mat b = new Mat(3, 1, CvType.CV_32F);
		// a.put(0, 0, new float[] { Double.valueOf(line.getX1()).floatValue() });
		// a.put(1, 0, new float[] { Double.valueOf(line.getY1()).floatValue() });
		// a.put(2, 0, new float[] { Double.valueOf(1d).floatValue() });
		// b.put(0, 0, new float[] { Double.valueOf(line.getX2()).floatValue() });
		// b.put(1, 0, new float[] { Double.valueOf(line.getY2()).floatValue() });
		// b.put(2, 0, new float[] { Double.valueOf(1d).floatValue() });
		// Mat an = new Mat(3, 1, CvType.CV_32F);
		// Mat bn = new Mat(3, 1, CvType.CV_32F);
		// Core.gemm(K.inv(), a, 1, new Mat(), 0, an);
		// Core.gemm(K.inv(), b, 1, new Mat(), 0, bn);
		// Mat li = an.cross(bn);
		// Core.normalize(li, li);
		// return li;
		// }

		// public Ransac<Line> vanishingPointRansac(double width, double height) {
		// int minimal_sample_set_dimension = 2;
		// double maxError = (float) 0.01623 * 2;
		// if (K == null) {
		// K = new Mat(3, 3, CvType.CV_32F, new Scalar(0));
		// K.put(0, 0, new float[] { Double.valueOf(width).floatValue() });
		// K.put(0, 2, new float[] { Double.valueOf(width / 2).floatValue() });
		// K.put(1, 1, new float[] { Double.valueOf(height).floatValue() });
		// K.put(1, 2, new float[] { Double.valueOf(height / 2).floatValue() });
		// K.put(2, 2, new float[] { 1 });
		// }
		// return new Ransac<>(getLines(), getModelProvider(minimal_sample_set_dimension, maxError), minimal_sample_set_dimension, 100, maxError, Double.valueOf(Math.floor(this.size() * 0.7)).intValue());
		// }

		// private Function<Collection<Line>, Model<Line>> getModelProvider(int minimal_sample_set_dimension, double maxError) {
		// return datas -> {
		// Mat vp;
		//
		// if (datas.size() == minimal_sample_set_dimension) {
		// Iterator<Line> it = datas.iterator();
		// vp = getLineMat(it.next()).cross(getLineMat(it.next()));
		// Core.normalize(vp, vp);
		// } else {
		// Stats.beginCumulative("RANSAC re-compute");
		// // Extract the line segments corresponding to the indexes contained in the set
		// Mat li_set = new Mat(3, datas.size(), CvType.CV_32F);
		// Mat tau = new Mat(datas.size(), datas.size(), CvType.CV_32F, new Scalar(0, 0, 0));
		//
		// int i = 0;
		// for (Line line : datas) {
		// Mat li = getLineMat(line);
		// li_set.put(0, i, li.get(0, 0));
		// li_set.put(1, i, li.get(1, 0));
		// li_set.put(2, i, li.get(2, 0));
		// tau.put(i, i, line.size());
		// i++;
		// }
		//
		// // Least squares solution
		// // Generate the matrix ATA (from LSS_set=A)
		// Mat L = li_set.t();
		// Mat ATA = new Mat(3, 3, CvType.CV_32F);
		// Mat dst = new Mat();
		//
		// Core.gemm(L.t(), tau.t(), 1, new Mat(), 0, dst);
		// Core.gemm(dst, tau, 1, new Mat(), 0, dst);
		// Core.gemm(dst, L, 1, new Mat(), 0, ATA);
		//
		// // Obtain eigendecomposition
		// Mat v = new Mat();
		// Core.SVDecomp(ATA, new Mat(), v, new Mat());
		//
		// // Check eigenvecs after SVDecomp
		// if (v.rows() < 3)
		// throw new IllegalStateException();
		//
		// // Assign the result (the last column of v, corresponding to the eigenvector with lowest eigenvalue)
		// vp = new Mat(3, 1, CvType.CV_32F);
		// vp.put(0, 0, v.get(0, 2));
		// vp.put(1, 0, v.get(1, 2));
		// vp.put(2, 0, v.get(2, 2));
		//
		// Core.normalize(vp, vp);
		//
		// Core.gemm(K, vp, 1, new Mat(), 0, vp);
		//
		// if (vp.get(2, 0)[0] != 0) {
		// vp.put(0, 0, new float[] { Double.valueOf(vp.get(0, 0)[0] / vp.get(2, 0)[0]).floatValue() });
		// vp.put(1, 0, new float[] { Double.valueOf(vp.get(1, 0)[0] / vp.get(2, 0)[0]).floatValue() });
		// vp.put(2, 0, new float[] { 1 });
		// } else {
		// // Since this is infinite, it is better to leave it calibrated
		// Core.gemm(K.inv(), vp, 1, new Mat(), 0, vp);
		// }
		// Stats.endCumulative("RANSAC re-compute");
		// }
		//
		// return new Model<Line>() {
		// @Override
		// public double computeError(Line line) {
		// Mat lineMat = getLineMat(line);
		// double di = vp.dot(lineMat);
		// di /= (Core.norm(vp) * Core.norm(lineMat));
		// return di * di;
		// }
		//
		// @Override
		// public double computeGlobalError(List<Line> datas, Collection<Line> consensusDatas) {
		// double globalError = 0;
		// for (Line line : datas) {
		// double error = computeError(line);
		// if (error > maxError)
		// error = maxError;
		// globalError += error;
		// }
		// globalError = globalError / datas.size();
		// return globalError;
		// }
		//
		// @Override
		// public Object[] getParams() {
		// return new Object[] { vp };
		// }
		//
		// };
		// };
		// }
	}

}