Example usage for org.opencv.imgproc Imgproc calcBackProject

Introduction

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

Prototype

public static void calcBackProject(List<Mat> images, MatOfInt channels, Mat hist, Mat dst, MatOfFloat ranges,
            double scale) 

Source Link

Usage

From source file:classes.ObjectFinder.java

private void backprojectObjectHistogram() {

    // Converting the current fram to HSV color space
    Mat hsvImage = new Mat(this.objectImage.size(), CvType.CV_8UC3);

    Imgproc.cvtColor(this.inputFrame, hsvImage, Imgproc.COLOR_BGR2HSV);

    // Getting the pixels that are in te specified ranges    
    int hmin = this.thresholdsVector.get(0);
    int hmax = this.thresholdsVector.get(1);
    int smin = this.thresholdsVector.get(2);
    int smax = this.thresholdsVector.get(3);
    int vmin = this.thresholdsVector.get(4);
    int vmax = this.thresholdsVector.get(5);

    Mat maskImage = new Mat(this.objectImage.size(), CvType.CV_8UC1);
    Core.inRange(hsvImage, new Scalar(hmin, smin, vmin), new Scalar(hmax, smax, vmax), maskImage);

    // Taking the hue channel of the image
    Mat hueImage = new Mat(hsvImage.size(), hsvImage.depth());

    MatOfInt fromto = new MatOfInt(0, 0);
    Core.mixChannels(Arrays.asList(hsvImage), Arrays.asList(hueImage), fromto);

    // Backprojecting the histogram over that hue channel image
    MatOfFloat ranges = new MatOfFloat(0, 180);
    MatOfInt channels = new MatOfInt(0);

    Imgproc.calcBackProject(Arrays.asList(hueImage), channels, this.objectHistogram, this.backprojectionImage,
            ranges, 1);// w w  w . ja va2 s.  c  om

    Core.bitwise_and(backprojectionImage, maskImage, backprojectionImage);

}

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From source file:imageprocess.ObjectFinder.java

public Mat find(final Mat image, MatOfInt channels, MatOfFloat ranges) {

    Mat result = new Mat();

    if (isIsSparse()) { // call the right function based on histogram type

        Imgproc.calcBackProject(Arrays.asList(image), channels, // vector specifying what histogram dimensions belong to what image channels
                ROIHistogram, // the histogram we are using
                result, // the resulting back projection image
                ranges, // the range of values, for each dimension
                255.0 // the scaling factor is chosen such that a histogram value of 1 maps to 255
        );//from  w w  w  .ja v a  2s.  c o  m

    } else {
        Imgproc.calcBackProject(Arrays.asList(image), channels, // vector specifying what histogram dimensions belong to what image channels
                ROIHistogram, // the histogram we are using
                result, // the resulting back projection image
                ranges, // the range of values, for each dimension
                255.0 // the scaling factor is chosen such that a histogram value of 1 maps to 255
        );
    }

    // Threshold back projection to obtain a binary image
    Mat thresholded = new Mat(result.rows(), result.cols(), result.type());
    if (getThreshold() > 0.0) {
        Imgproc.threshold(result, thresholded, 255 * getThreshold(), 255, THRESH_BINARY);
    }

    return thresholded;
}

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From source file:info.jmfavreau.bifrostcore.imageprocessing.ImageToColor.java

License:Open Source License

private Mat extract_main_region(Mat img, Mat roi) {
    Mat hist = new Mat();
    int h_bins = 30;
    int s_bins = 32;
    MatOfInt mHistSize = new MatOfInt(h_bins, s_bins);

    MatOfFloat mRanges = new MatOfFloat(0, 179, 0, 255);
    MatOfInt mChannels = new MatOfInt(0, 1);

    Imgproc.calcHist(Arrays.asList(img), mChannels, roi, hist, mHistSize, mRanges, false);

    Core.normalize(hist, hist, 0, 255, Core.NORM_MINMAX, -1, new Mat());

    Mat backproj = new Mat();
    Imgproc.calcBackProject(Arrays.asList(img), mChannels, hist, backproj, mRanges, 1);

    Log.w("bifrostcore",
            "Number of pixels in the biggest region: " + String.valueOf(Core.countNonZero(backproj)));
    return backproj.mul(roi);
}

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From source file:nz.ac.auckland.lablet.vision.CamShiftTracker.java

License:Open Source License

/**
 * Gets the location of an object in a frame. Assumes you have called setRegionOfInterest,
 * which informs CamShiftTracker which object to track.
 *
 * @param frame The frame to search for the object in.
 * @return The location and bounds of the object, represented by a Rect.
 *///from ww w  .java  2s  .c o  m
public Rect getObjectLocation(Bitmap frame) {
    Mat image = new Mat();
    Utils.bitmapToMat(frame, image);

    //        Mat out = new Mat(image.rows(), image.cols(), image.type());
    //        image.convertTo(out, -1, 2.0, 2.0);
    //        image = out;

    toHsv(image, hsvMin, hsvMax);

    ArrayList<Mat> hsvs = new ArrayList<>();
    hsvs.add(hsv);

    Imgproc.calcBackProject(hsvs, new MatOfInt(0), hist, backproj, ranges, 1);
    Core.bitwise_and(backproj, mask, backproj);

    try {
        Rect tempTrackWindow = trackWindow.clone();
        RotatedRect result = Video.CamShift(backproj, trackWindow, termCriteria);

        if (result.size.equals(new Size(0, 0)) && result.angle == 0 && result.center.equals(new Point(0, 0))) {
            trackWindow = tempTrackWindow;
            return null;
        }
    } catch (Exception e) {
        Log.e(TAG, "Shit went down: ", e);
        return null;
    }

    return trackWindow.clone();
}

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