Java Code Examples for org.opencv.core.Mat#create()

void Contours() {
    Mat grayMat = new Mat();
    Mat cannyEdges = new Mat();
    Mat hierarchy = new Mat();

    List<MatOfPoint> contourList = new ArrayList<MatOfPoint>(); //A list to store all the contours

    //Converting the image to grayscale
    Imgproc.cvtColor(originalMat, grayMat, Imgproc.COLOR_BGR2GRAY);

    Imgproc.Canny(originalMat, cannyEdges, 10, 100);

    //finding contours
    Imgproc.findContours(cannyEdges, contourList, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);

    //Drawing contours on a new image
    Mat contours = new Mat();
    contours.create(cannyEdges.rows(), cannyEdges.cols(), CvType.CV_8UC3);
    Random r = new Random();
    for (int i = 0; i < contourList.size(); i++) {
        Imgproc.drawContours(contours, contourList, i, new Scalar(r.nextInt(255), r.nextInt(255), r.nextInt(255)), -1);
    }
    //Converting Mat back to Bitmap
    Utils.matToBitmap(contours, currentBitmap);
    imageView.setImageBitmap(currentBitmap);
}
 

private void calcBoardCornerPositions(Mat corners) {
    final int cn = 3;
    float positions[] = new float[mCornersSize * cn];

    for (int i = 0; i < mPatternSize.height; i++) {
        for (int j = 0; j < mPatternSize.width * cn; j += cn) {
            positions[(int) (i * mPatternSize.width * cn + j + 0)] =
                    (2 * (j / cn) + i % 2) * (float) mSquareSize;
            positions[(int) (i * mPatternSize.width * cn + j + 1)] =
                    i * (float) mSquareSize;
            positions[(int) (i * mPatternSize.width * cn + j + 2)] = 0;
        }
    }
    corners.create(mCornersSize, 1, CvType.CV_32FC3);
    corners.put(0, 0, positions);
}
 

private double computeReprojectionErrors(List<Mat> objectPoints,
                                         List<Mat> rvecs, List<Mat> tvecs, Mat perViewErrors) {
    MatOfPoint2f cornersProjected = new MatOfPoint2f();
    double totalError = 0;
    double error;
    float viewErrors[] = new float[objectPoints.size()];

    MatOfDouble distortionCoefficients = new MatOfDouble(mDistortionCoefficients);
    int totalPoints = 0;
    for (int i = 0; i < objectPoints.size(); i++) {
        MatOfPoint3f points = new MatOfPoint3f(objectPoints.get(i));
        Calib3d.projectPoints(points, rvecs.get(i), tvecs.get(i),
                mCameraMatrix, distortionCoefficients, cornersProjected);
        error = Core.norm(mCornersBuffer.get(i), cornersProjected, Core.NORM_L2);

        int n = objectPoints.get(i).rows();
        viewErrors[i] = (float) Math.sqrt(error * error / n);
        totalError  += error * error;
        totalPoints += n;
    }
    perViewErrors.create(objectPoints.size(), 1, CvType.CV_32FC1);
    perViewErrors.put(0, 0, viewErrors);

    return Math.sqrt(totalError / totalPoints);
}
 

void HoughLines() {

        Mat grayMat = new Mat();
        Mat cannyEdges = new Mat();
        Mat lines = new Mat();

        //Converting the image to grayscale
        Imgproc.cvtColor(originalMat, grayMat, Imgproc.COLOR_BGR2GRAY);

        Imgproc.Canny(grayMat, cannyEdges, 10, 100);

        Imgproc.HoughLinesP(cannyEdges, lines, 1, Math.PI / 180, 50, 20, 20);

        Mat houghLines = new Mat();
        houghLines.create(cannyEdges.rows(), cannyEdges.cols(), CvType.CV_8UC1);

        //Drawing lines on the image
        for (int i = 0; i < lines.cols(); i++) {
            double[] points = lines.get(0, i);
            double x1, y1, x2, y2;

            x1 = points[0];
            y1 = points[1];
            x2 = points[2];
            y2 = points[3];

            Point pt1 = new Point(x1, y1);
            Point pt2 = new Point(x2, y2);

            //Drawing lines on an image
            Imgproc.line(houghLines, pt1, pt2, new Scalar(255, 0, 0), 1);
        }

        //Converting Mat back to Bitmap
        Utils.matToBitmap(houghLines, currentBitmap);
        imageView.setImageBitmap(currentBitmap);

    }
 

void HoughCircles() {
    Mat grayMat = new Mat();
    Mat cannyEdges = new Mat();
    Mat circles = new Mat();

    //Converting the image to grayscale
    Imgproc.cvtColor(originalMat, grayMat, Imgproc.COLOR_BGR2GRAY);

    Imgproc.Canny(grayMat, cannyEdges, 10, 100);

    Imgproc.HoughCircles(cannyEdges, circles, Imgproc.CV_HOUGH_GRADIENT, 1, cannyEdges.rows() / 15);//, grayMat.rows() / 8);

    Mat houghCircles = new Mat();
    houghCircles.create(cannyEdges.rows(), cannyEdges.cols(), CvType.CV_8UC1);

    //Drawing lines on the image
    for (int i = 0; i < circles.cols(); i++) {
        double[] parameters = circles.get(0, i);
        double x, y;
        int r;

        x = parameters[0];
        y = parameters[1];
        r = (int) parameters[2];

        Point center = new Point(x, y);

        //Drawing circles on an image
        Imgproc.circle(houghCircles, center, r, new Scalar(255, 0, 0), 1);
    }

    //Converting Mat back to Bitmap
    Utils.matToBitmap(houghCircles, currentBitmap);
    imageView.setImageBitmap(currentBitmap);
}
 

/**
	 * 
	 * @param image
	 * @param T
	 * @param patch OUTPUT
	 * @param patchSize
	 */
	void generate(final Mat image, final Mat T, Mat patch, Size patchSize, final RNG rng){
	    patch.create( patchSize, image.type() );
	    if( backgroundMin != backgroundMax ) {
	    	Core.randu(patch, backgroundMin, backgroundMax);
	    	// TODO if that null scalar OK or should it be new Scalar(0) ?
	    	Imgproc.warpAffine(image, patch, T, patchSize, Imgproc.INTER_LINEAR, Imgproc.BORDER_TRANSPARENT, null);
	    } else {
	    	Imgproc.warpAffine(image, patch, T, patchSize, Imgproc.INTER_LINEAR, Imgproc.BORDER_CONSTANT, new Scalar(backgroundMin));
	    }

	    int ksize = randomBlur ? rng.nextInt() % 9 - 5 : 0;
	    if( ksize > 0 ) {
	        ksize = ksize * 2 + 1;
	        Imgproc.GaussianBlur(patch, patch, new Size(ksize, ksize), 0, 0);
	    }

	    if( noiseRange > 0 ) {
	        final Mat noise = new Mat(patchSize, image.type());
	        int delta = (image.depth() == CvType.CV_8U ? 128 : (image.depth() == CvType.CV_16U ? 32768 : 0));
	        Core.randn(noise, delta, noiseRange);
	        
	        // TODO this was different !!
	        Core.addWeighted(patch, 1, noise, 1, -delta, patch);
	        
//	        if( backgroundMin != backgroundMax )
//	            addWeighted(patch, 1, noise, 1, -delta, patch);
//	        else
//	        {
//	            for( int i = 0; i < patchSize.height; i++ )
//	            {
//	                uchar* prow = patch.ptr<uchar>(i);
//	                const uchar* nrow =  noise.ptr<uchar>(i);
//	                for( int j = 0; j < patchSize.width; j++ )
//	                    if( prow[j] != backgroundMin )
//	                        prow[j] = saturate_cast<uchar>(prow[j] + nrow[j] - delta);
//	            }
//	        }
	    }		
	}
 

/**
 * 直线检测
 *
 * @param origin   原始bitmap
 * @param callback 回调
 */
public void hough(Bitmap origin, ProcessCallback callback) {
    if (origin == null) {
        return;
    }
    try {
        Bitmap bitmap = Bitmap.createBitmap(origin.getWidth(), origin.getHeight(), Bitmap.Config.RGB_565);
        Utils.bitmapToMat(origin, rgbMat);
        Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);
        Mat edges = new Mat();
        Mat src = new Mat(origin.getHeight(), origin.getWidth(), CvType.CV_8UC4);
        Mat lines = new Mat();
        // 拷贝
        Mat origination = new Mat(src.size(), CvType.CV_8UC1);
        src.copyTo(origination);
        // 通过Canny得到边缘图
        Imgproc.cvtColor(origination, grayMat, Imgproc.COLOR_BGR2GRAY);
        Imgproc.Canny(grayMat, edges, 50, 200);
        // 获取直线图
        Imgproc.HoughLinesP(edges, lines, 1, Math.PI / 180, 10, 0, 10);
        Mat houghLines = new Mat();
        houghLines.create(edges.rows(), edges.cols(), CvType.CV_8UC1);
        // 绘制直线
        for (int i = 0; i < lines.rows(); i++) {
            double[] points = lines.get(i, 0);
            if (null != points) {
                double x1, y1, x2, y2;
                x1 = points[0];
                y1 = points[1];
                x2 = points[2];
                y2 = points[3];
                Point pt1 = new Point(x1, y1);
                Point pt2 = new Point(x2, y2);
                Imgproc.line(houghLines, pt1, pt2, new Scalar(55, 100, 195), 3);
            }
        }
        Utils.matToBitmap(houghLines, bitmap);
        callback.onSuccess(bitmap);
    } catch (Exception e) {
        callback.onFailed(e.getMessage());
    }
}
 

/**
 * 
 * @param srcCenter
 * @param dstCenter
 * @param transform OUTPUT
 * @param inverse
 */
private void generateRandomTransform(Point srcCenter, Point dstCenter, Mat transform, boolean inverse) {
	MatOfDouble tempRand = new MatOfDouble(0d, 0d);
	Core.randu(tempRand, lambdaMin, lambdaMax);
	final double[] rands = tempRand.toArray();
	final double lambda1 = rands[0];
	final double lambda2 = rands[1];
	Core.randu(tempRand, thetaMin, thetaMax);
	final double theta = tempRand.toArray()[0];
	Core.randu(tempRand, phiMin, phiMax);
	final double phi = tempRand.toArray()[0];
	
	
	// Calculate random parameterized affine transformation A,
    // A = T(patch center) * R(theta) * R(phi)' * S(lambda1, lambda2) * R(phi) * T(-pt)
    final double st = Math.sin(theta);
    final double ct = Math.cos(theta);
    final double sp = Math.sin(phi);
    final double cp = Math.cos(phi);
    final double c2p = cp*cp;
    final double s2p = sp*sp;

    final double A = lambda1*c2p + lambda2*s2p;
    final double B = (lambda2 - lambda1)*sp*cp;
    final double C = lambda1*s2p + lambda2*c2p;

    final double Ax_plus_By = A*srcCenter.x + B*srcCenter.y;
    final double Bx_plus_Cy = B*srcCenter.x + C*srcCenter.y;

    transform.create(2, 3, CvType.CV_64F);
    transform.put(0, 0, A*ct - B*st);
    transform.put(0, 1, B*ct - C*st);
    transform.put(0, 2, -ct*Ax_plus_By + st*Bx_plus_Cy + dstCenter.x);
    transform.put(1, 0, A*st + B*ct);
    transform.put(1, 1, B*st + C*ct);
    transform.put(1, 2, -st*Ax_plus_By - ct*Bx_plus_Cy + dstCenter.y);

    if( inverse ){
        Imgproc.invertAffineTransform(transform, transform);
    }
}