Example usage for org.opencv.core Mat Mat

Introduction

In this page you can find the example usage for org.opencv.core Mat Mat.

Prototype

public Mat() 

Source Link

Usage

From source file:de.hftl_projekt.ict.MainActivity.java

/**
 * method to reduce the color (quantize) the given matrix (image)
 * @param image input matrix/*from   w ww. j  a va2s  .com*/
 * @return modified input matrix
 */
public Mat reduceColors(Mat image) {
    if (channels.size() == 0) {
        for (int i = 0; i < image.channels(); i++) {
            Mat channel = new Mat(); // fill array with a matrix for each channel
            channels.add(channel);
        }

    }
    int i = 0;
    // process each channel individually
    for (Mat c : channels) {
        Core.extractChannel(image, c, i);
        // binary quantization (set threshold so each color (R, G, B) can have the value (0 or 255) )
        // and using the Otsu algorithm to optimize the quantization
        Imgproc.threshold(c, c, 0, 255, Imgproc.THRESH_BINARY_INV + Imgproc.THRESH_OTSU);
        i++;
    }
    Core.merge(channels, image); // put the channel back together
    return image;
}

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From source file:de.hhn.android.licenseplatedecoder.decoder.CountryExtractor.java

/**
 * Constructor//  w  w w.  j  a  v  a 2 s. c  o m
 * @param nativeAddress input image pointer address
 * @param withoutStripInputAddr image pointer address in order to store the cropped image without the blue strip
 */
public CountryExtractor(long nativeAddress, long withoutStripInputAddr) {
    this.nativeInputAddr = nativeAddress;
    this.withoutStripInputAddr = withoutStripInputAddr;
    this.withoutBlueStrip = new Mat();

    /** OCR ENGINE INIT */
    this.baseApi = new TessBaseAPI();
    this.baseApi.setDebug(true);
    this.baseApi.init("/sdcard/", "blueBand"); // myDir + "/tessdata/eng.traineddata" must be present
    this.baseApi.setVariable("tessedit_char_whitelist", "ABCDFGHIKLOPRSTZ");
    this.baseApi.setPageSegMode(TessBaseAPI.PageSegMode.PSM_SINGLE_CHAR);

    ArrayList<Mat> countryCode = getCharacters();

    StringBuffer strb = new StringBuffer();
    for (Mat elem : countryCode) {

        Bitmap pass = Bitmap.createBitmap(elem.cols(), elem.rows(), Bitmap.Config.ARGB_8888);
        Utils.matToBitmap(elem, pass, true);

        baseApi.setImage(pass);
        String recognizedText = baseApi.getUTF8Text();
        strb.append(recognizedText);
        baseApi.clear();
        pass.recycle();
    }
    this.result = strb.toString();
    baseApi.end();
    baseApi = null;
    countryCode = null;
}

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From source file:de.hhn.android.licenseplatedecoder.decoder.DecodingEngine.java

/**
 * Get the country code using CountryExtractor
 * @return the country code/*from  ww w . j  av  a  2s . c  o  m*/
 */
public String getCountryCode() {
    Mat nativeOpencv = new Mat();
    org.opencv.android.Utils.bitmapToMat(inputImg, nativeOpencv);
    Mat res = new Mat(nativeOpencv.rows(), nativeOpencv.cols(), nativeOpencv.type());
    org.opencv.imgproc.Imgproc.cvtColor(nativeOpencv, res, Imgproc.COLOR_RGBA2BGR);
    nativeOpencv = null;
    Mat withoutStrip = new Mat();

    CountryExtractor ce = new CountryExtractor(res.nativeObj, withoutStrip.nativeObj);
    return ce.getResult();
}

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From source file:de.hhn.android.licenseplatedecoder.decoder.DecodingEngine.java

/**
 * Get the license plate using LPSegmenter
 * @return the license plate//  www  .  j  a  v  a2 s .c  o m
 */
public String getLicensePlate() {
    Mat nativeOpencv = new Mat();
    org.opencv.android.Utils.bitmapToMat(inputImg, nativeOpencv);
    Mat res = new Mat(nativeOpencv.rows(), nativeOpencv.cols(), nativeOpencv.type());
    org.opencv.imgproc.Imgproc.cvtColor(nativeOpencv, res, Imgproc.COLOR_RGBA2BGR);
    nativeOpencv = null;

    LPSegmenter lp = new LPSegmenter(res.nativeObj, this.countryCodeNonAutomatic);
    return lp.getResult();
}

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From source file:de.hu_berlin.informatik.spws2014.mapever.entzerrung.CornerDetector.java

License:Open Source License

/**
 * Guesses the most likly corners of a distorted map within an image.
 * Expects OpenCV to be initialized.//from   ww w.j a va  2  s. c  o m
 * The results are already pretty good but could propably be improved
 * via tweaking the parameters or adding some additional line filtering
 * criteria(like them being kind of parallel for instance...)
 * 
 * @param gray_img A grayscale image in OpenCVs Mat format.
 * @return An array of propable corner points in the following form: {x0,y0,x1,y1,x2,y2,x3,y3} or null on error.
 **/
public static Point[] guess_corners(Mat gray_img) {
    Mat lines = new Mat();
    Imgproc.Canny(gray_img, gray_img, THRESHOLD0, THRESHOLD1, APERTURE_SIZE, false);
    Imgproc.HoughLinesP(gray_img, lines, RHO, THETA, HOUGH_THRESHOLD,
            Math.min(gray_img.cols(), gray_img.rows()) / MIN_LINE_LENGTH_FRACTION, MAX_LINE_GAP);

    double[][] edge_lines = filter_lines(lines, gray_img.size());

    Point[] ret_val = new Point[4];
    ret_val[0] = find_intercept_point(edge_lines[0], edge_lines[2]);
    ret_val[1] = find_intercept_point(edge_lines[0], edge_lines[3]);
    ret_val[2] = find_intercept_point(edge_lines[1], edge_lines[3]);
    ret_val[3] = find_intercept_point(edge_lines[1], edge_lines[2]);

    // do sanity checks and return null on invalid coordinates
    for (int i = 0; i < 4; i++) {
        // check if coordinates are outside image boundaries
        if (ret_val[i].x < 0 || ret_val[i].y < 0 || ret_val[i].x > gray_img.width()
                || ret_val[i].y > gray_img.height()) {
            return null;
        }

        // check if point equal to other point
        for (int j = i + 1; j < 4; j++) {
            if (ret_val[j].x == ret_val[i].x && ret_val[j].y == ret_val[i].y) {
                return null;
            }
        }
    }

    return ret_val;
}

---

From source file:de.hu_berlin.informatik.spws2014.mapever.entzerrung.EntzerrungsView.java

License:Open Source License

/**
 * Use corner detection algorithm to find and set corners automatically.
 *///from  w w  w.j  a v a 2 s. c o  m
public void calcCornersWithDetector() {
    // Bitmap berechnen, die fr CD-Algorithmus runterskaliert wurde
    Bitmap bmp32 = getCDScaledBitmap();

    if (bmp32 == null || getImageWidth() <= 0) {
        Log.e("EntzerrungsView/calcCornersWithDetector",
                bmp32 == null ? "getCDScaledBitmap() returned null!" : "getImageWidth() is nonpositive!");
        calcCornerDefaults();
        return;
    }

    float sampleSize = getImageWidth() / bmp32.getWidth();

    org.opencv.core.Point[] corner_points;

    try {
        Mat imgMat = new Mat();
        Utils.bitmapToMat(bmp32, imgMat);
        Mat greyMat = new Mat();
        Imgproc.cvtColor(imgMat, greyMat, Imgproc.COLOR_RGB2GRAY);

        corner_points = CornerDetector.guess_corners(greyMat);
    } catch (CvException e) {
        Log.w("EntzerrungsView/calcCornersWithDetector", "Corner detection failed with CvException");
        e.printStackTrace();

        // it seems that the image type is not supported by the corner detection algorithm (GIF?)
        // it won't be deskewable either, so deactivate that feature
        showCorners(false);
        imageTypeSupportsDeskew = false;

        calcCornerDefaults();
        return;
    } catch (UnsatisfiedLinkError e) {
        Log.w("EntzerrungsView/calcCornersWithDetector", "OpenCV not available");
        openCVLoadError = true;
        calcCornerDefaults();
        return;
    }

    // Im Fehlerfall Standardecken verwenden
    if (corner_points == null) {
        Log.w("EntzerrungsView/calcCornersWithDetector", "Corner detection returned null");
        calcCornerDefaults();
        return;
    }

    // Koordinaten auf ursprngliche Bildgre hochrechnen
    for (int i = 0; i < corner_points.length; i++) {
        corner_points[i].x *= sampleSize;
        corner_points[i].y *= sampleSize;
    }

    Log.d("Corner points", "0: " + corner_points[0] + " 1: " + corner_points[1] + " 2: " + corner_points[2]
            + " 3: " + corner_points[3]);

    // Algorithmusergebnis als Eckpunkte verwenden
    corners[0].setPosition(corner_points[0]);
    corners[1].setPosition(corner_points[1]);
    corners[2].setPosition(corner_points[2]);
    corners[3].setPosition(corner_points[3]);

    // Sortieren (obwohl sie eigentlich sortiert sein sollten...?)
    sortCorners();

    punkte_gesetzt = true;
}

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From source file:de.vion.eyetracking.cameracalib.calibration.opencv.CameraCalibrator.java

public void calibrate() {
    ArrayList<Mat> rvecs = new ArrayList<Mat>();
    ArrayList<Mat> tvecs = new ArrayList<Mat>();
    Mat reprojectionErrors = new Mat();
    ArrayList<Mat> objectPoints = new ArrayList<Mat>();
    objectPoints.add(Mat.zeros(this.mCornersSize, 1, CvType.CV_32FC3));
    calcBoardCornerPositions(objectPoints.get(0));
    for (int i = 1; i < this.mCornersBuffer.size(); i++) {
        objectPoints.add(objectPoints.get(0));
    }//from  ww  w  .j  a v  a2  s . com

    Calib3d.calibrateCamera(objectPoints, this.mCornersBuffer, this.mImageSize, this.mCameraMatrix,
            this.mDistortionCoefficients, rvecs, tvecs, this.mFlags);

    this.mIsCalibrated = Core.checkRange(this.mCameraMatrix) && Core.checkRange(this.mDistortionCoefficients);

    this.mRms = computeReprojectionErrors(objectPoints, rvecs, tvecs, reprojectionErrors);
}

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From source file:detectiontest.ParticleDetector.java

/**
 * Particle detection algorithm./* w w w  . ja va 2  s.  c  o m*/
 * 
 * @param image an image where we want to detect
 * @return list of detected particles
 */
public static List<Particle> detect(Mat image) {

    // blur the image to denoise
    Imgproc.blur(image, image, new Size(3, 3));

    // thresholds the image
    Mat thresholded = new Mat();
    Imgproc.threshold(image, thresholded, THRESHOLD, MAX, Imgproc.THRESH_TOZERO_INV);

    // detect contours
    List<MatOfPoint> contours = new ArrayList<>();
    Imgproc.findContours(thresholded, contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE,
            ORIGIN);

    // create particle from each contour
    List<Particle> particles = new ArrayList<>();
    for (MatOfPoint contour : contours) {
        particles.add(new Particle(contour));
    }

    return particles;
}

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From source file:detectors.CCdetection.java

/**
 * Method to scan image with x classifier
 *//*from   ww  w. j av a2 s  . c  o m*/
public void scanImage(String path) {
    CascadeClassifier faceCC = new CascadeClassifier();
    faceCC.load("res/haarcascade_frontalface_alt.xml");

    //Matrix to hold image to be scanned
    Mat image = new Mat();
    image = Highgui.imread(path, IMREAD_COLOR);

    Mat rgb = new Mat();
    Mat gray = new Mat();
    image.copyTo(rgb);
    image.copyTo(gray);

    //Create integral image from the grayscale version of frame 
    Imgproc.cvtColor(rgb, gray, Imgproc.COLOR_BGR2GRAY);
    Imgproc.equalizeHist(gray, gray);

    //MatOfRect detection window initialized
    MatOfRect detects = new MatOfRect();
    faceCC.detectMultiScale(gray, detects);

    //Print out number of detected rect objects detected
    if (detects.toArray().length != 0) {
        System.out.printf("Detected %s\n", detects.toArray().length);
    }
}

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From source file:detectors.CCdetection.java

/**
 * Method to scan video with x classifier
 * NOT COMPLETE/* w  w w  .j a  v a2  s.c om*/
 */
public void scanVideo() {
    //Initialize video capture object to 0(default camera device)
    VideoCapture vc = new VideoCapture(0);

    //String path = "";

    //Initialize and load in classifier
    CascadeClassifier faceCC = new CascadeClassifier();
    faceCC.load("res/haarcascade_frontalface_default.xml");

    //Matrix(opencv core image object) to hold the image frame coming from the capture stream
    Mat image = new Mat();

    boolean isFound = false;
    while (!isFound) {
        //VideoCapture read combines grab and retrieve methods to decode and return the frame
        vc.read(image);
        if (image != null) {

            //Initialize new Mats to hold the original colored frame and the grayscaled frame
            Mat rgb = new Mat();
            Mat gray = new Mat();
            image.copyTo(rgb);
            image.copyTo(gray);

            //Create integral image from the grayscale version of frame 
            Imgproc.cvtColor(rgb, gray, Imgproc.COLOR_BGR2GRAY);
            Imgproc.equalizeHist(gray, gray);

            //MatOfRect detection window initialized
            MatOfRect detects = new MatOfRect();
            faceCC.detectMultiScale(gray, detects);

            //Print out number of detected rect objects detected
            if (detects.toArray().length != 0) {
                System.out.printf("Detected %s\n", detects.toArray().length);
                //prodFound(UPC,"T");
                isFound = true;
            }

        } else {
            break;
        }
    }
}

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