Example usage for org.opencv.imgproc Imgproc Sobel

List of usage examples for org.opencv.imgproc Imgproc Sobel

Introduction

In this page you can find the example usage for org.opencv.imgproc Imgproc Sobel.

Prototype

public static void Sobel(Mat src, Mat dst, int ddepth, int dx, int dy, int ksize, double scale, double delta,
            int borderType) 

Source Link

Usage

From source file:ImageReade.java

public static void detectLetter(Mat img) {
    ArrayList<Rect> boundRect = new ArrayList<>();
    Mat img_gray, img_sobel, img_threshold, element;
    img_gray = new Mat();
    img_sobel = new Mat();
    img_threshold = new Mat();
    element = new Mat();
    Imgproc.cvtColor(img, img_gray, Imgproc.COLOR_BGRA2GRAY);
    imshow("Rec img_gray", img_gray);
    Imgproc.Sobel(img_gray, img_sobel, CvType.CV_8U, 1, 0, 3, 1, 0, Imgproc.BORDER_DEFAULT);
    imshow("Rec img_sobel", img_sobel);
    Imgproc.threshold(img_sobel, img_threshold, 0, 255, CV_THRESH_OTSU + CV_THRESH_BINARY);
    imshow("Rec img_threshold", img_threshold);

    element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(16, 6));

    Imgproc.morphologyEx(img_threshold, img_threshold, CV_MOP_CLOSE, element);
    imshow("Rec img_threshold second", img_threshold);

    List<MatOfPoint> contours = new ArrayList<MatOfPoint>();

    //Imgproc.findContours(img_threshold, contours, new Mat(), Imgproc.RETR_LIST,Imgproc.CHAIN_APPROX_SIMPLE);
    Imgproc.findContours(img_threshold, contours, new Mat(), 0, 1);

    for (int i = 0; i < contours.size(); i++) {
        System.out.println(Imgproc.contourArea(contours.get(i)));
        //            if (Imgproc.contourArea(contours.get(i)) > 100) {
        //                //Imgproc.approxPolyDP( contours.get(i), contours_poly[i], 3, true );
        //                Rect rect = Imgproc.boundingRect(contours.get(i));
        //                System.out.println(rect.height);
        //                if (rect.width > rect.height) {
        //                    //System.out.println(rect.x +","+rect.y+","+rect.height+","+rect.width);
        //                    Core.rectangle(img, new Point(rect.x,rect.y), new Point(rect.x+rect.width,rect.y+rect.height),new Scalar(0,0,255));
        //                }
        //                    
        //                    
        //            }
        if (Imgproc.contourArea(contours.get(i)) > 100) {
            MatOfPoint2f mMOP2f1 = new MatOfPoint2f();
            MatOfPoint2f mMOP2f2 = new MatOfPoint2f();
            contours.get(i).convertTo(mMOP2f1, CvType.CV_32FC2);
            Imgproc.approxPolyDP(mMOP2f1, mMOP2f2, 3, true);
            mMOP2f2.convertTo(contours.get(i), CvType.CV_32S);
            Rect rect = Imgproc.boundingRect(contours.get(i));
            if (rect.width > rect.height) {
                Core.rectangle(img, new Point(rect.x, rect.y),
                        new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 0, 255));
            }//from   w  w w .  j ava 2 s.com
        }
    }
    imshow("Rec Detected", img);
}

From source file:OCV_Sobel.java

License:Open Source License

@Override
public void run(ImageProcessor ip) {
    if (ip.getBitDepth() == 8) {
        // srcdst
        int imw = ip.getWidth();
        int imh = ip.getHeight();
        byte[] srcdst_bytes = (byte[]) ip.getPixels();

        // mat//from  w  w w .  j  a v  a2s  .  c  o  m
        Mat src_mat = new Mat(imh, imw, CvType.CV_8UC1);
        Mat dst_mat = new Mat(imh, imw, CvType.CV_8UC1);

        // run
        src_mat.put(0, 0, srcdst_bytes);
        Imgproc.Sobel(src_mat, dst_mat, src_mat.depth(), dx, dy, ksize, scale, delta,
                INT_BORDERTYPE[indBorderType]);
        dst_mat.get(0, 0, srcdst_bytes);
    } else if (ip.getBitDepth() == 16) {
        // srcdst
        int imw = ip.getWidth();
        int imh = ip.getHeight();
        short[] srcdst_shorts = (short[]) ip.getPixels();

        // mat
        Mat src_mat = new Mat(imh, imw, CvType.CV_16S);
        Mat dst_mat = new Mat(imh, imw, CvType.CV_16S);

        // run
        src_mat.put(0, 0, srcdst_shorts);
        Imgproc.Sobel(src_mat, dst_mat, src_mat.depth(), dx, dy, ksize, scale, delta,
                INT_BORDERTYPE[indBorderType]);
        dst_mat.get(0, 0, srcdst_shorts);
    } else if (ip.getBitDepth() == 32) {
        // srcdst
        int imw = ip.getWidth();
        int imh = ip.getHeight();
        float[] srcdst_floats = (float[]) ip.getPixels();

        // mat
        Mat src_mat = new Mat(imh, imw, CvType.CV_32F);
        Mat dst_mat = new Mat(imh, imw, CvType.CV_32F);

        // run
        src_mat.put(0, 0, srcdst_floats);
        Imgproc.Sobel(src_mat, dst_mat, src_mat.depth(), dx, dy, ksize, scale, delta,
                INT_BORDERTYPE[indBorderType]);
        dst_mat.get(0, 0, srcdst_floats);
    } else {
        IJ.error("Wrong image format");
    }
}

From source file:ThirdTry.java

public static void detectLetter(Mat img, Mat m2) {
    ArrayList<Rect> boundRect = new ArrayList<>();
    Mat img_gray, img_sobel, img_threshold, element;
    img_gray = new Mat();
    img_sobel = new Mat();
    img_threshold = new Mat();
    element = new Mat();
    Imgproc.cvtColor(img, img_gray, Imgproc.COLOR_BGRA2GRAY);
    //imshow("Rec img_gray", img_gray);
    Imgproc.Sobel(img_gray, img_sobel, CvType.CV_8UC1, 1, 0, 3, 1, 0, Imgproc.BORDER_DEFAULT);
    //imshow("Rec img_sobel", img_sobel);
    Imgproc.threshold(m2, img_threshold, 0, 255, CV_THRESH_OTSU + CV_THRESH_BINARY);
    //imshow("Rec img_threshold", img_threshold);

    element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(3, 2));

    Imgproc.morphologyEx(m2, img_threshold, CV_MOP_CLOSE, element);
    imshow("Rec img_threshold second", img_threshold);

    element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(12, 12));
    Imgproc.morphologyEx(img_threshold, img_threshold, CV_MOP_CLOSE, element);
    //imshow("Rec img_threshold second", img_threshold);

    List<MatOfPoint> contours = new ArrayList<MatOfPoint>();

    //Imgproc.findContours(img_threshold, contours, new Mat(), Imgproc.RETR_LIST,Imgproc.CHAIN_APPROX_SIMPLE);
    Imgproc.findContours(img_threshold, contours, new Mat(), 0, 1);

    for (int i = 0; i < contours.size(); i++) {
        System.out.println(Imgproc.contourArea(contours.get(i)));
        //            if (Imgproc.contourArea(contours.get(i)) > 100) {
        //                //Imgproc.approxPolyDP( contours.get(i), contours_poly[i], 3, true );
        //                Rect rect = Imgproc.boundingRect(contours.get(i));
        //                System.out.println(rect.height);
        //                if (rect.width > rect.height) {
        //                    //System.out.println(rect.x +","+rect.y+","+rect.height+","+rect.width);
        //                    Core.rectangle(img, new Point(rect.x,rect.y), new Point(rect.x+rect.width,rect.y+rect.height),new Scalar(0,0,255));
        //                }
        //                    
        //                    
        //            }
        if (Imgproc.contourArea(contours.get(i)) > 100) {
            MatOfPoint2f mMOP2f1 = new MatOfPoint2f();
            MatOfPoint2f mMOP2f2 = new MatOfPoint2f();
            contours.get(i).convertTo(mMOP2f1, CvType.CV_32FC2);
            Imgproc.approxPolyDP(mMOP2f1, mMOP2f2, 3, true);
            mMOP2f2.convertTo(contours.get(i), CvType.CV_32S);
            Rect rect = Imgproc.boundingRect(contours.get(i));
            if (rect.width > rect.height) {
                Core.rectangle(img, new Point(rect.x, rect.y),
                        new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 0, 255));
            }// ww  w  .  j a  v  a  2 s .co m
        }
    }
    //imshow("Rec Detected", img);
}

From source file:javaapplication1.Ocv.java

void doSobel(String input, String output) {
    // load the image and read it into a matrix
    File f2 = new File(input);
    Mat image = Highgui.imread(this.input);

    // blur the image
    Imgproc.GaussianBlur(image, image, new Size(3, 3), 0, 0, Imgproc.BORDER_DEFAULT);

    // convert the image to gray
    Mat gray = new Mat();
    Imgproc.cvtColor(image, gray, Imgproc.COLOR_BGR2GRAY);

    // parameters for our conversion
    int scale = 1;
    int delta = 0;
    int ddepth = CvType.CV_16S;

    // figure out the X gradient, get its absolute value
    Mat gx = new Mat();
    Imgproc.Sobel(gray, gx, ddepth, 1, 0, 3, scale, delta, Imgproc.BORDER_DEFAULT);
    Mat abs_gx = new Mat();
    Core.convertScaleAbs(gx, abs_gx);//from ww  w  .  jav  a2 s.c om

    // do the same for Y
    Mat gy = new Mat();
    Imgproc.Sobel(gray, gy, ddepth, 0, 1, 3, scale, delta, Imgproc.BORDER_DEFAULT);
    Mat abs_gy = new Mat();
    Core.convertScaleAbs(gy, abs_gy);

    // do a simple combine, and save it
    Mat grad = new Mat();
    Core.addWeighted(abs_gx, 0.5, abs_gy, 0.5, 0, grad);
    Highgui.imwrite(this.output, grad);
}