Java Imgproc.pyrDown方法代码示例

import org.opencv.imgproc.Imgproc; //导入方法依赖的package包/类
public static List<Mat> buildPyramid(Mat mat, int maxLevel) {
    List<Mat> pyramid = new ArrayList<>();
    pyramid.add(mat);
    for (int i = 0; i < maxLevel; i++) {
        Mat m = new Mat((mat.rows() + 1) / 2, (mat.cols() + 1) / 2, mat.type());
        Imgproc.pyrDown(mat, m);
        pyramid.add(m);
        mat = m;
    }
    return pyramid;
}
 

import org.opencv.imgproc.Imgproc; //导入方法依赖的package包/类
/**
 * 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));
    }
}
 

import org.opencv.imgproc.Imgproc; //导入方法依赖的package包/类
/**
 * 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));
}