Question

我在我的Android应用程序中使用ColorBlobDetector Open CV进行颜色检测，但没有此类中使用的方法的文档。我想知道这个课程中setHsvColor(Scalar hsvColor)的用途是什么。任何人都可以帮助我。

我正在关注github上给出的样本，即 https://github.com/Itseez/opencv/tree/master/samples/android/color-blob-detection

整个代码是

public class ColorBlobDetector {
// Lower and Upper bounds for range checking in HSV color space
private Scalar mLowerBound = new Scalar(0);
private Scalar mUpperBound = new Scalar(0);
// Minimum contour area in percent for contours filtering
private static double mMinContourArea = 0.1;
// Color radius for range checking in HSV color space
private Scalar mColorRadius = new Scalar(25,50,50,0);
private Mat mSpectrum = new Mat();
private List<MatOfPoint> mContours = new ArrayList<MatOfPoint>();

// Cache
Mat mPyrDownMat = new Mat();
Mat mHsvMat = new Mat();
Mat mMask = new Mat();
Mat mDilatedMask = new Mat();
Mat mHierarchy = new Mat();

public void setColorRadius(Scalar radius) {
    mColorRadius = radius;
}

public void setHsvColor(Scalar hsvColor) {
    double minH = (hsvColor.val[0] >= mColorRadius.val[0]) ? hsvColor.val[0]-mColorRadius.val[0] : 0;
    double maxH = (hsvColor.val[0]+mColorRadius.val[0] <= 255) ? hsvColor.val[0]+mColorRadius.val[0] : 255;

    mLowerBound.val[0] = minH;
    mUpperBound.val[0] = maxH;

    mLowerBound.val[1] = hsvColor.val[1] - mColorRadius.val[1];
    mUpperBound.val[1] = hsvColor.val[1] + mColorRadius.val[1];

    mLowerBound.val[2] = hsvColor.val[2] - mColorRadius.val[2];
    mUpperBound.val[2] = hsvColor.val[2] + mColorRadius.val[2];

    mLowerBound.val[3] = 0;
    mUpperBound.val[3] = 255;

    Mat spectrumHsv = new Mat(1, (int)(maxH-minH), CvType.CV_8UC3);

    for (int j = 0; j < maxH-minH; j++) {
        byte[] tmp = {(byte)(minH+j), (byte)255, (byte)255};
        spectrumHsv.put(0, j, tmp);
    }

    Imgproc.cvtColor(spectrumHsv, mSpectrum, Imgproc.COLOR_HSV2RGB_FULL, 4);
}

public Mat getSpectrum() {
    return mSpectrum;
}

public void setMinContourArea(double area) {
    mMinContourArea = area;
}

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);
        }
    }
}

public List<MatOfPoint> getContours() {
    return mContours;
}
}

Answer 1

通常对于具有特定颜色的物体检测，它们首先将RGB空间转换为HSV（HSI）空间。原因是在HSV颜色空间中，V表示照明。因此，颜色用来自源的实际反射来表示H和S值 - 您可以看到它们的实际颜色。（参见HSV）。您需要做的就是比较颜色，以便找到具有特定颜色的适当对象。根据这个你可以理解代码！

ColorBlobDetector打开CV文档Android

1 个答案: