Example usage for org.opencv.imgproc Imgproc goodFeaturesToTrack

Introduction

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

Prototype

public static void goodFeaturesToTrack(Mat image, MatOfPoint corners, int maxCorners, double qualityLevel,
            double minDistance) 

Source Link

Usage

From source file:emotion.Eyebrow.java

public static void Harris(Mat img, boolean rightEyeFlag) {
    //Harris point extraction
    Mat harrisTestimg;/* w  w  w .ja  v  a  2 s  . com*/
    harrisTestimg = img.clone();
    cvtColor(harrisTestimg, harrisTestimg, Imgproc.COLOR_BGR2GRAY);
    threshold(harrisTestimg, harrisTestimg, 200, 255, Imgproc.THRESH_BINARY_INV);
    Mat struct = Imgproc.getStructuringElement(Imgproc.MORPH_CROSS, new Size(3, 3));
    erode(harrisTestimg, harrisTestimg, struct);
    dilate(harrisTestimg, harrisTestimg, struct);
    imwrite("intermediateHaaris.jpg", harrisTestimg);
    harrisTestimg.convertTo(harrisTestimg, CV_8UC1);
    ArrayList<MatOfPoint> contours = new ArrayList<>();
    Mat hierarchy = new Mat();

    Imgproc.findContours(harrisTestimg, contours, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_NONE);

    //System.out.println("Average Y for contours:");
    float[] averageY = new float[contours.size()];
    for (int i = 0; i < contours.size(); ++i) {
        //We calculate mean of Y coordinates for each contour
        for (int j = 0; j < contours.get(i).total(); ++j) {
            int val = (int) contours.get(i).toArray()[j].y;
            averageY[i] += val;
        }
        averageY[i] /= contours.get(i).total();
        //System.out.println(i+") "+averageY[i]);

        if (averageY[i] <= img.height() / 2 && //We consider just up half of an image
                contours.get(i).total() >= img.width()) //and longer than threshold
            Imgproc.drawContours(harrisTestimg, contours, i, new Scalar(255, 255, 255));
        else
            Imgproc.drawContours(harrisTestimg, contours, i, new Scalar(0, 0, 0));
    }

    MatOfPoint features = new MatOfPoint();
    Imgproc.goodFeaturesToTrack(harrisTestimg, features, 100, 0.00001, 0);

    //We draw just 2 extreme points- first and last
    Point eyebrowsPoints[] = new Point[2];
    for (int i = 0; i < features.toList().size(); i++) {
        if (i == 0) {
            eyebrowsPoints[0] = new Point(harrisTestimg.width() / 2, 0);
            eyebrowsPoints[1] = new Point(harrisTestimg.width() / 2, 0);
        }
        if (features.toArray()[i].x < eyebrowsPoints[0].x
                && features.toArray()[i].y < harrisTestimg.height() / 2) {
            eyebrowsPoints[0] = features.toArray()[i];
        }
        if (features.toArray()[i].x > eyebrowsPoints[1].x
                && features.toArray()[i].y < harrisTestimg.height() / 2) {
            eyebrowsPoints[1] = features.toArray()[i];
        }
    }
    StaticFunctions.drawCross(img, eyebrowsPoints[1], StaticFunctions.Features.EYEBROWS_ENDS);
    StaticFunctions.drawCross(img, eyebrowsPoints[0], StaticFunctions.Features.EYEBROWS_ENDS);
    imwrite("testHaris.jpg", img);
    if (rightEyeFlag) {
        EyeRegion.rightInnerEyebrowsCorner = eyebrowsPoints[0];
        EyeRegion.rightInnerEyebrowsCorner.x += Eye.rightRect.x;
        EyeRegion.rightInnerEyebrowsCorner.y += Eye.rightRect.y;

        EyeRegion.rightOuterEyebrowsCorner = eyebrowsPoints[1];
        EyeRegion.rightOuterEyebrowsCorner.x += Eye.rightRect.x;
        EyeRegion.rightOuterEyebrowsCorner.y += Eye.rightRect.y;
    } else {
        EyeRegion.leftInnerEyebrowsCorner = eyebrowsPoints[1];
        EyeRegion.leftInnerEyebrowsCorner.x += Eye.leftRect.x;
        EyeRegion.leftInnerEyebrowsCorner.y += Eye.leftRect.y;

        EyeRegion.leftOuterEyebrowsCorner = eyebrowsPoints[0];
        EyeRegion.leftOuterEyebrowsCorner.x += Eye.leftRect.x;
        EyeRegion.leftOuterEyebrowsCorner.y += Eye.leftRect.y;
    }
}

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