Java Code Examples for org.opencv.imgproc.Imgproc#morphologyEx()

public static void denoise() {
        String imgInPath = "captchaExample.jpg";
        imgInPath = "MyCaptcha.PNG";
        imgInPath = "blurredtext.jpg";
        String imgOutPath = "captchaNoiseRemovedExample.png";
        imgOutPath = "MyNoiseRemovedCaptcha.PNG";

        Mat image = Imgcodecs.imread(imgInPath);
        Mat out = new Mat();
        Mat tmp = new Mat();
        Mat kernel = new Mat(new Size(3, 3), CvType.CV_8UC1, new Scalar(255));
//        Mat kernel = new Mat(image.size(), CvType.CV_8UC1, new Scalar(255));
        Imgproc.morphologyEx(image, tmp, Imgproc.MORPH_OPEN, kernel);
        Imgproc.morphologyEx(tmp, out, Imgproc.MORPH_CLOSE, kernel);
        Imgcodecs.imwrite(imgOutPath, out);
    }
 

Mat buildSkeleton(Mat img){
    Mat morph = Imgproc.getStructuringElement(Imgproc.CV_SHAPE_CROSS, new Size(3, 3));
    Mat skel = new Mat(img.size(), CvType.CV_8UC1, Scalar.all(0));
    Mat eroded = new Mat();
    Mat temp = new Mat();

    boolean done = false;

    do{
        Imgproc.morphologyEx(img, eroded, Imgproc.MORPH_ERODE, morph);
        Imgproc.morphologyEx(eroded, temp, Imgproc.MORPH_DILATE, morph);
        Core.subtract(img, temp, temp);
        Core.bitwise_or(skel, temp, skel);
        eroded.copyTo(img);

        done = Core.countNonZero(img) == 0;
    }while (!done);

    return skel;
}
 

public static List<Region> findChanges(FindInput2 findInput) {
  findInput.setAttributes();
  Mat previousGray = SXOpenCV.newMat();
  Mat nextGray = SXOpenCV.newMat();
  Mat mDiffAbs = SXOpenCV.newMat();
  Mat mDiffThresh = SXOpenCV.newMat();
  Imgproc.cvtColor(findInput.getBase(), previousGray, toGray);
  Imgproc.cvtColor(findInput.getTarget(), nextGray, toGray);
  Core.absdiff(previousGray, nextGray, mDiffAbs);
  Imgproc.threshold(mDiffAbs, mDiffThresh, PIXEL_DIFF_THRESHOLD, 0.0, Imgproc.THRESH_TOZERO);

  List<Region> rectangles = new ArrayList<>();
  if (Core.countNonZero(mDiffThresh) > IMAGE_DIFF_THRESHOLD) {
    Imgproc.threshold(mDiffAbs, mDiffAbs, PIXEL_DIFF_THRESHOLD, 255, Imgproc.THRESH_BINARY);
    Imgproc.dilate(mDiffAbs, mDiffAbs, SXOpenCV.newMat());
    Mat se = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5));
    Imgproc.morphologyEx(mDiffAbs, mDiffAbs, Imgproc.MORPH_CLOSE, se);
    List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
    Mat mHierarchy = SXOpenCV.newMat();
    Imgproc.findContours(mDiffAbs, contours, mHierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
    for (MatOfPoint contour : contours) {
      int x1 = 99999;
      int y1 = 99999;
      int x2 = 0;
      int y2 = 0;
      List<org.opencv.core.Point> points = contour.toList();
      for (Point point : points) {
        int x = (int) point.x;
        int y = (int) point.y;
        if (x < x1) x1 = x;
        if (x > x2) x2 = x;
        if (y < y1) y1 = y;
        if (y > y2) y2 = y;
      }
      Region rect = new Region(x1, y1, x2 - x1, y2 - y1);
      rectangles.add(rect);
    }
  }
  return rectangles;
}
 

public static List<Match> doFindChanges(Image original, Image changed) {
  List<Match> changes = new ArrayList<>();
  if (changed.isValid()) {
    int PIXEL_DIFF_THRESHOLD = 3;
    int IMAGE_DIFF_THRESHOLD = 5;
    Mat previousGray = SXOpenCV.newMat();
    Mat nextGray = SXOpenCV.newMat();
    Mat mDiffAbs = SXOpenCV.newMat();
    Mat mDiffTresh = SXOpenCV.newMat();

    Imgproc.cvtColor(original.getContent(), previousGray, toGray);
    Imgproc.cvtColor(changed.getContent(), nextGray, toGray);
    Core.absdiff(previousGray, nextGray, mDiffAbs);
    Imgproc.threshold(mDiffAbs, mDiffTresh, PIXEL_DIFF_THRESHOLD, 0.0, Imgproc.THRESH_TOZERO);

    if (Core.countNonZero(mDiffTresh) > IMAGE_DIFF_THRESHOLD) {
      Imgproc.threshold(mDiffAbs, mDiffAbs, PIXEL_DIFF_THRESHOLD, 255, Imgproc.THRESH_BINARY);
      Imgproc.dilate(mDiffAbs, mDiffAbs, SXOpenCV.newMat());
      Mat se = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5));
      Imgproc.morphologyEx(mDiffAbs, mDiffAbs, Imgproc.MORPH_CLOSE, se);

      List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
      Mat mHierarchy = SXOpenCV.newMat();
      Imgproc.findContours(mDiffAbs, contours, mHierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
      changes = contoursToRectangle(contours);
    }
  }
  return changes;
}
 

public void noiseRemoval() {
//        Mat Kernel = cv::Mat(cv::Size(Maximum_Width_of_Noise,Maximum_Height_of_noise),CV_8UC1,cv::Scalar(255));        
        Mat Kernel = new Mat(new Size(3, 3), CvType.CV_8U, new Scalar(255));
        Mat source = Imgcodecs.imread("noiseExample.png");
        Mat temp = new Mat();
        Mat topHat = new Mat();
        Mat destination = new Mat();

        Imgproc.morphologyEx(source, temp, Imgproc.MORPH_OPEN, Kernel);
        Imgproc.morphologyEx(temp, destination, Imgproc.MORPH_CLOSE, Kernel);
//        Imgproc.morphologyEx(temp, topHat, Imgproc.MORPH_GRADIENT, Kernel);
//        Imgproc.morphologyEx(topHat, destination, Imgproc.MORPH_CLOSE, Kernel);
        Imgcodecs.imwrite("noiseRemovedExample.png", source);
    }
 

public static List<MatOfPoint> findContoursForMRZ(Mat src){
    Mat img = src.clone();
    src.release();
    double ratio = getScaleRatio(img.size());
    int width = (int) (img.size().width / ratio);
    int height = (int) (img.size().height / ratio);
    Size newSize = new Size(width, height);
    Mat resizedImg = new Mat(newSize, CvType.CV_8UC4);
    Imgproc.resize(img, resizedImg, newSize);

    Mat gray = new Mat();
    Imgproc.cvtColor(resizedImg, gray, Imgproc.COLOR_BGR2GRAY);
    Imgproc.medianBlur(gray, gray, 3);
    //Imgproc.blur(gray, gray, new Size(3, 3));

    Mat morph = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(13, 5));
    Mat dilatedImg = new Mat();
    Imgproc.morphologyEx(gray, dilatedImg, Imgproc.MORPH_BLACKHAT, morph);
    gray.release();

    Mat gradX = new Mat();
    Imgproc.Sobel(dilatedImg, gradX, CvType.CV_32F, 1, 0);
    dilatedImg.release();
    Core.convertScaleAbs(gradX, gradX, 1, 0);
    Core.MinMaxLocResult minMax = Core.minMaxLoc(gradX);
    Core.convertScaleAbs(gradX, gradX, (255/(minMax.maxVal - minMax.minVal)),
            - ((minMax.minVal * 255) / (minMax.maxVal - minMax.minVal)));
    Imgproc.morphologyEx(gradX, gradX, Imgproc.MORPH_CLOSE, morph);

    Mat thresh = new Mat();
    Imgproc.threshold(gradX, thresh, 0, 255, Imgproc.THRESH_OTSU);
    gradX.release();
    morph.release();

    morph = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(21, 21));
    Imgproc.morphologyEx(thresh, thresh, Imgproc.MORPH_CLOSE, morph);
    Imgproc.erode(thresh, thresh, new Mat(), new Point(-1, -1), 4);
    morph.release();

    int col = (int) resizedImg.size().width;
    int p = (int) (resizedImg.size().width * 0.05);
    int row = (int) resizedImg.size().height;
    for(int i = 0; i < row; i++)
    {
        for(int j = 0; j < p; j++){
            thresh.put(i, j, 0);
            thresh.put(i, col-j, 0);
        }
    }

    List<MatOfPoint> contours = new ArrayList<>();
    Mat hierarchy = new Mat();
    Imgproc.findContours(thresh, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
    hierarchy.release();

    Log.d(TAG, "contours found: " + contours.size());

    Collections.sort(contours, new Comparator<MatOfPoint>() {
        @Override
        public int compare(MatOfPoint o1, MatOfPoint o2) {
            return Double.valueOf(Imgproc.contourArea(o2)).compareTo(Imgproc.contourArea(o1));
        }
    });

    return contours;
}
 

public static List<Element> detectChanges(Mat base, Mat mChanged) {
  int PIXEL_DIFF_THRESHOLD = 3;
  int IMAGE_DIFF_THRESHOLD = 5;
  Mat mBaseGray = Element.getNewMat();
  Mat mChangedGray = Element.getNewMat();
  Mat mDiffAbs = Element.getNewMat();
  Mat mDiffTresh = Element.getNewMat();
  Mat mChanges = Element.getNewMat();
  List<Element> rectangles = new ArrayList<>();

  Imgproc.cvtColor(base, mBaseGray, toGray);
  Imgproc.cvtColor(mChanged, mChangedGray, toGray);
  Core.absdiff(mBaseGray, mChangedGray, mDiffAbs);
  Imgproc.threshold(mDiffAbs, mDiffTresh, PIXEL_DIFF_THRESHOLD, 0.0, Imgproc.THRESH_TOZERO);
  if (Core.countNonZero(mDiffTresh) > IMAGE_DIFF_THRESHOLD) {
    Imgproc.threshold(mDiffAbs, mDiffAbs, PIXEL_DIFF_THRESHOLD, 255, Imgproc.THRESH_BINARY);
    Imgproc.dilate(mDiffAbs, mDiffAbs, Element.getNewMat());
    Mat se = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5));
    Imgproc.morphologyEx(mDiffAbs, mDiffAbs, Imgproc.MORPH_CLOSE, se);

    List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
    Mat mHierarchy = Element.getNewMat();
    Imgproc.findContours(mDiffAbs, contours, mHierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
    rectangles = contoursToRectangle(contours);

    Core.subtract(mDiffAbs, mDiffAbs, mChanges);
    Imgproc.drawContours(mChanges, contours, -1, new Scalar(255));
    //logShow(mDiffAbs);
  }
  return rectangles;
}