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package com.emaraic.distance;

import org.bytedeco.javacpp.FloatPointer; import org.bytedeco.javacpp.Loader; import org.bytedeco.javacpp.indexer.UByteIndexer; import org.bytedeco.javacpp.opencv_core.CvContour; import org.bytedeco.javacpp.opencv_core.CvMemStorage; import org.bytedeco.javacpp.opencv_core.CvPoint; import org.bytedeco.javacpp.opencv_core.CvSeq; import org.bytedeco.javacpp.opencv_core.IplImage; import org.bytedeco.javacpp.opencv_core.Mat; import org.bytedeco.javacpp.opencv_core.Point; import org.bytedeco.javacpp.opencv_core.Point2f; import org.bytedeco.javacpp.opencv_core.Scalar; import static org.bytedeco.javacpp.helper.opencv_core.CV_RGB; import static org.bytedeco.javacpp.opencv_core.IPL_DEPTH_8U; import org.bytedeco.javacpp.opencv_core.Size; import static org.bytedeco.javacpp.opencv_core.cvCreateImage; import static org.bytedeco.javacpp.opencv_core.cvCreateMemStorage; import static org.bytedeco.javacpp.opencv_core.cvGetSize; import static org.bytedeco.javacpp.opencv_core.cvPoint; import org.bytedeco.javacpp.opencv_imgproc; import static org.bytedeco.javacpp.opencv_imgproc.COLOR_BGR2HSV; import static org.bytedeco.javacpp.opencv_imgproc.CV_BGR2GRAY; import static org.bytedeco.javacpp.opencv_imgproc.CV_CHAIN_APPROX_SIMPLE; import static org.bytedeco.javacpp.opencv_imgproc.CV_RETR_LIST; import static org.bytedeco.javacpp.opencv_imgproc.CV_THRESH_OTSU; import static org.bytedeco.javacpp.opencv_imgproc.contourArea; import static org.bytedeco.javacpp.opencv_imgproc.cvCircle; import static org.bytedeco.javacpp.opencv_imgproc.cvCvtColor; import static org.bytedeco.javacpp.opencv_imgproc.cvFindContours; import static org.bytedeco.javacpp.opencv_imgproc.cvThreshold; import static org.bytedeco.javacpp.opencv_imgproc.cvtColor; import static org.bytedeco.javacpp.opencv_imgproc.putText; import static org.bytedeco.javacpp.opencv_imgproc.resize; import org.bytedeco.javacv.CanvasFrame; import org.bytedeco.javacv.Frame; import org.bytedeco.javacv.FrameGrabber; import org.bytedeco.javacv.OpenCVFrameConverter; import org.bytedeco.javacv.OpenCVFrameGrabber;

/** * * @author Taha Emara * Website: http://www.emaraic.com * Email : [email protected] * Created on: Mar 10, 2018 */ public class DistanceMeasurement {

private static final double FOCAL_LENGTH = 906.107;//focal length in pixels obtained from Calibration class
private static final double RADIUS_OF_MARKER = 1.0;
private static final OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();

public static boolean isPixelBlue(Mat image, int x, int y) {
    if (x < 0 || y < 0) {
        return false;
    }
    UByteIndexer srcIndexer = image.createIndexer();
    int[] hsv = new int[3];
    boolean blue = false;
    for (int i = 0; i < srcIndexer.rows(); i++) {
        for (int j = 0; j < srcIndexer.cols(); j++) {
            if (j == x && i == y) {
                srcIndexer.get(i, j, hsv);
                if (hsv[0] >= 100 && hsv[0] <= 130 && hsv[1] >= 50 && hsv[1] <= 255 && hsv[2] >= 50 && hsv[2] <= 255) {
                    blue = true;
                }
            }
        }
    }
    return blue;
}

public static void main(String[] args) {
    try {
        OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
        grabber.start();
        CanvasFrame canvas = new CanvasFrame("Distance Measurement - Emaraic");

        canvas.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
        canvas.setCanvasSize(660, 660);
        canvas.setLocationRelativeTo(null);
        while (true) {
            Frame frame = grabber.grab();
            IplImage grabbedImage = converter.convert(frame);

            if (grabbedImage != null && canvas.isVisible()) {
                Mat img = converter.convertToMat(frame);

                /*Resize Image (comment this section if you want to use default resolution)*/
                Size size = new Size(640, 640);
                resize(img, img, size);
                grabbedImage = new IplImage(img);

                /*Invert to HSV color space*/
                Mat imghsv = new Mat();
                cvtColor(img, imghsv, COLOR_BGR2HSV);

                /*Convert image to grayscale*/
                IplImage gray = cvCreateImage(cvGetSize(grabbedImage), IPL_DEPTH_8U, 1);
                cvCvtColor(grabbedImage, gray, CV_BGR2GRAY);


                /*Binarising Image*/
                IplImage binimg = cvCreateImage(cvGetSize(gray), IPL_DEPTH_8U, 1);
                cvThreshold(gray, binimg, 0, 255, CV_THRESH_OTSU);

                /*Find countour */
                CvMemStorage storage = cvCreateMemStorage(0);
                CvSeq contours = new CvSeq();
                cvFindContours(binimg, storage, contours, Loader.sizeof(CvContour.class), CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0, 0));
                CvSeq ptr = new CvSeq();
                Mat m = new Mat(grabbedImage);
                for (ptr = contours; ptr != null; ptr = ptr.h_next()) {
                    /*Find Enclosing Circles*/
                    Point2f center = new Point2f();
                    FloatPointer radius = new FloatPointer(1f);
                    opencv_imgproc.minEnclosingCircle(new Mat(ptr), center, radius);
                    /*Check, if the color of the center picel is blue, it is our marker*/
                    if (isPixelBlue(imghsv, (int) center.x(), (int) center.y())) {
                        double area = contourArea(new Mat(ptr), true);
                        if (area > 100) {
                            cvCircle(grabbedImage, new CvPoint((int) center.x(), (int) center.y()), (int) radius.get(0),
                                    CV_RGB(0, 255, 0), 3, 0, 0);
                            float rad = radius.get(0);
                            System.out.println("Radius is " + rad);
                            double distance = (FOCAL_LENGTH * RADIUS_OF_MARKER) / rad;
                            System.out.println("Distance in cm " + distance);
                            putText(m, "Distance is : " + distance + " cm", new Point(200, 100), 0, 0.5, new Scalar(0, 255, 0, 0));
                        }
                    }
                }//End for  countors
                canvas.showImage(converter.convert(m));
                Thread.sleep(150);
            }//End if
        }//End while
    } catch (FrameGrabber.Exception | InterruptedException ex) {
        ex.printStackTrace();
    }
}

}

this is javacpp code, it's working fine, I like to achieve the same work in javascript with help of opencv.js, but many functions are not available, can you help me to find them?

package com.emaraic.distance;

/** * * @author Taha Emara * Website: http://www.emaraic.com * Email : [email protected] * Created on: Mar 10, 2018 */ org.bytedeco.javacv.OpenCVFrameGrabber; public class DistanceMeasurement {

private static final double FOCAL_LENGTH = 906.107;//focal length in pixels obtained from Calibration class
private static final double RADIUS_OF_MARKER = 1.0;
private static final OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();

public static boolean isPixelBlue(Mat image, int x, int y) {
    if (x < 0 || y < 0) {
        return false;
    }
    UByteIndexer srcIndexer = image.createIndexer();
    int[] hsv = new int[3];
    boolean blue = false;
    for (int i = 0; i < srcIndexer.rows(); i++) {
        for (int j = 0; j < srcIndexer.cols(); j++) {
            if (j == x && i == y) {
                srcIndexer.get(i, j, hsv);
                if (hsv[0] >= 100 && hsv[0] <= 130 && hsv[1] >= 50 && hsv[1] <= 255 && hsv[2] >= 50 && hsv[2] <= 255) {
                    blue = true;
                }
            }
        }
    }
    return blue;
}

public static void main(String[] args) {
    try {
        OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
        grabber.start();
        CanvasFrame canvas = new CanvasFrame("Distance Measurement - Emaraic");

        canvas.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
        canvas.setCanvasSize(660, 660);
        canvas.setLocationRelativeTo(null);
        while (true) {
            Frame frame = grabber.grab();
            IplImage grabbedImage = converter.convert(frame);

            if (grabbedImage != null && canvas.isVisible()) {
                Mat img = converter.convertToMat(frame);

                /*Resize Image (comment this section if you want to use default resolution)*/
                Size size = new Size(640, 640);
                resize(img, img, size);
                grabbedImage = new IplImage(img);

                /*Invert to HSV color space*/
                Mat imghsv = new Mat();
                cvtColor(img, imghsv, COLOR_BGR2HSV);

                /*Convert image to grayscale*/
                IplImage gray = cvCreateImage(cvGetSize(grabbedImage), IPL_DEPTH_8U, 1);
                cvCvtColor(grabbedImage, gray, CV_BGR2GRAY);


                /*Binarising Image*/
                IplImage binimg = cvCreateImage(cvGetSize(gray), IPL_DEPTH_8U, 1);
                cvThreshold(gray, binimg, 0, 255, CV_THRESH_OTSU);

                /*Find countour */
                CvMemStorage storage = cvCreateMemStorage(0);
                CvSeq contours = new CvSeq();
                cvFindContours(binimg, storage, contours, Loader.sizeof(CvContour.class), CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0, 0));
                CvSeq ptr = new CvSeq();
                Mat m = new Mat(grabbedImage);
                for (ptr = contours; ptr != null; ptr = ptr.h_next()) {
                    /*Find Enclosing Circles*/
                    Point2f center = new Point2f();
                    FloatPointer radius = new FloatPointer(1f);
                    opencv_imgproc.minEnclosingCircle(new Mat(ptr), center, radius);
                    /*Check, if the color of the center picel is blue, it is our marker*/
                    if (isPixelBlue(imghsv, (int) center.x(), (int) center.y())) {
                        double area = contourArea(new Mat(ptr), true);
                        if (area > 100) {
                            cvCircle(grabbedImage, new CvPoint((int) center.x(), (int) center.y()), (int) radius.get(0),
                                    CV_RGB(0, 255, 0), 3, 0, 0);
                            float rad = radius.get(0);
                            System.out.println("Radius is " + rad);
                            double distance = (FOCAL_LENGTH * RADIUS_OF_MARKER) / rad;
                            System.out.println("Distance in cm " + distance);
                            putText(m, "Distance is : " + distance + " cm", new Point(200, 100), 0, 0.5, new Scalar(0, 255, 0, 0));
                        }
                    }
                }//End for  countors
                canvas.showImage(converter.convert(m));
                Thread.sleep(150);
            }//End if
        }//End while
    } catch (FrameGrabber.Exception | InterruptedException ex) {
        ex.printStackTrace();
    }
}

}

this is javacpp code, it's working fine, I like to achieve the same work in javascript with help of opencv.js, but many functions are not available, can you help me to find them?