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

The following examples show how to use org.opencv.imgproc.Imgproc#pyrDown() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: ColorBlobDetector.java    From FaceT with Mozilla Public License 2.0 5 votes vote down vote up 
public void process(Mat rgbaImage) {
    Imgproc.pyrDown(rgbaImage, mPyrDownMat);
    Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

    Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

    Core.inRange(mHsvMat, mLowerBound, mUpperBound, mMask);
    Imgproc.dilate(mMask, mDilatedMask, new Mat());

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

    Imgproc.findContours(mDilatedMask, contours, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

    // Find max contour area
    double maxArea = 0;
    Iterator<MatOfPoint> each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint wrapper = each.next();
        double area = Imgproc.contourArea(wrapper);
        if (area > maxArea)
            maxArea = area;
    }

    // Filter contours by area and resize to fit the original image size
    mContours.clear();
    each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint contour = each.next();
        if (Imgproc.contourArea(contour) > mMinContourArea*maxArea) {
            Core.multiply(contour, new Scalar(4,4), contour);
            mContours.add(contour);
        }
    }
}
Example 2
Source File: ColorBlobDetector.java    From OpenCV-AndroidSamples with MIT License 5 votes vote down vote up 
public void process(Mat rgbaImage) {
    Imgproc.pyrDown(rgbaImage, mPyrDownMat);
    Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

    Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

    Core.inRange(mHsvMat, mLowerBound, mUpperBound, mMask);
    Imgproc.dilate(mMask, mDilatedMask, new Mat());

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

    Imgproc.findContours(mDilatedMask, contours, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

    // Find max contour area
    double maxArea = 0;
    Iterator<MatOfPoint> each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint wrapper = each.next();
        double area = Imgproc.contourArea(wrapper);
        if (area > maxArea)
            maxArea = area;
    }

    // Filter contours by area and resize to fit the original image size
    mContours.clear();
    each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint contour = each.next();
        if (Imgproc.contourArea(contour) > mMinContourArea*maxArea) {
            Core.multiply(contour, new Scalar(4,4), contour);
            mContours.add(contour);
        }
    }
}
Example 3
Source File: ColorBlobDetector.java    From hand_finger_recognition_android with MIT License 5 votes vote down vote up 
public void process(Mat rgbaImage) {
    Imgproc.pyrDown(rgbaImage, mPyrDownMat);
	Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

    Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

    Core.inRange(mHsvMat, mLowerBound, mUpperBound, mMask);
    Imgproc.dilate(mMask, mDilatedMask, new Mat());

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

    Imgproc.findContours(mDilatedMask, contours, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

    // Find max contour area
    double maxArea = 0;
    Iterator<MatOfPoint> each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint wrapper = each.next();
        double area = Imgproc.contourArea(wrapper);
        if (area > maxArea)
            maxArea = area;
    }

    // Filter contours by area and resize to fit the original image size
    mContours.clear();
    each = contours.iterator();
    while (each.hasNext()) {
        MatOfPoint contour = each.next();
        if (Imgproc.contourArea(contour) > mMinContourArea*maxArea) {
            Core.multiply(contour, new Scalar(4,4), contour);
            mContours.add(contour);
        }
    }
}
Example 4
Source File: ColorBlobDetector.java    From FTCVision with MIT License 4 votes vote down vote up 
/**
 * Process an rgba image. The results can be drawn on retrieved later.
 * This method does not modify the image.
 *
 * @param rgbaImage An RGBA image matrix
 */
public void process(Mat rgbaImage) {
    Imgproc.pyrDown(rgbaImage, mPyrDownMat);
    Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

    Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

    //Test whether we need two inRange operations (only if the hue crosses over 255)
    if (upperBound.getScalar().val[0] <= 255) {
        Core.inRange(mHsvMat, lowerBound.getScalar(), upperBound.getScalar(), mMask);
    } else {
        //We need two operations - we're going to OR the masks together
        Scalar lower = lowerBound.getScalar().clone();
        Scalar upper = upperBound.getScalar().clone();
        while (upper.val[0] > 255)
            upper.val[0] -= 255;
        double tmp = lower.val[0];
        lower.val[0] = 0;
        //Mask 1 - from 0 to n
        Core.inRange(mHsvMat, lower, upper, mMaskOne);
        //Mask 2 - from 255-n to 255
        lower.val[0] = tmp;
        upper.val[0] = 255;

        Core.inRange(mHsvMat, lower, upper, mMask);
        //OR the two masks
        Core.bitwise_or(mMaskOne, mMask, mMask);
    }

    //Dilate (blur) the mask to decrease processing power
    Imgproc.dilate(mMask, mDilatedMask, new Mat());

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

    Imgproc.findContours(mDilatedMask, contourListTemp, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

    // Filter contours by area and resize to fit the original image size
    contours.clear();
    for (MatOfPoint c : contourListTemp) {
        Core.multiply(c, new Scalar(4, 4), c);
        contours.add(new Contour(c));
    }
}
Example 5
Source File: Filter.java    From FTCVision with MIT License 2 votes vote down vote up 
/**
 * Downsample and blur an image (using a Gaussian pyramid kernel)
 *
 * @param img   The image
 * @param scale The scale, a number greater than 1
 */
public static void downsample(Mat img, double scale) {
    Imgproc.pyrDown(img, img, new Size((double) img.width() / scale, (double) img.height() / scale));
}