数螺丝

    HImage img("D:\\123.png");

    HTuple ch = img.CountChannels();
    HImage gray = (ch == 3) ? img.Rgb1ToGray() : img;

    gray = gray.MedianImage("circle", 3, "mirrored");

    // 边缘提取
    HXLDCont contours = gray.EdgesSubPix(
        "canny",
        1,
        20,
        40);

    // 看有多少条轮廓
    HTuple numContours = contours.CountObj();

    CString msg;
    msg.Format(_T("轮廓数=%d"), numContours.I());
    AfxMessageBox(msg);

    if (numContours.I() < 1)
        return;

    // 取第一条轮廓
    HXLDCont contour =
        contours.SelectObj(1);

    // 获取轮廓点
    HTuple rows, cols;
    contour.GetContourXld(
        &rows,
        &cols);

    // 点数
    int len = rows.Length();

    CString str;
    str.Format(
        _T("轮廓点数=%d"),
        len);

    AfxMessageBox(str);

    //---------------------------------
    // 手动按 row 排序
    //---------------------------------

    std::vector<std::pair<double, double>> pts;

    for (int i = 0; i < len; i++)
    {
        pts.push_back(
            std::make_pair(
                rows[i].D(),
                cols[i].D()));
    }

    std::sort(
        pts.begin(),
        pts.end(),
        [](const std::pair<double, double>& a,
            const std::pair<double, double>& b)
        {
            return a.first < b.first;
        });

    //---------------------------------
    // 分10段找峰值
    //---------------------------------

    int M = 10;
    int step = (int)pts.size() / M;

    std::vector<std::pair<double, double>> peaks;

    for (int k = 0; k < M; k++)
    {
        int start = k * step;
        int end =
            (k == M - 1) ?
            (int)pts.size() :
            (k + 1) * step;

        double maxY = -1e9;
        double maxX = 0;

        for (int i = start; i < end; i++)
        {
            if (pts[i].second > maxY)
            {
                maxY = pts[i].second;
                maxX = pts[i].first;
            }
        }

        peaks.push_back(
            std::make_pair(maxX, maxY));
    }

    //---------------------------------
    // 显示
    //---------------------------------

    HWindow win;
    win.OpenWindow(
        0,
        0,
        1000,
        800,
        0,
        "visible",
        "");

    win.DispObj(gray);

    win.SetColor("red");

    for (size_t i = 0; i < peaks.size(); i++)
    {
        win.DispCross(
            peaks[i].first,
            peaks[i].second,
            20,
            0);
    }

    CString result;
    result.Format(
        _T("检测峰值=%d"),
        (int)peaks.size());

    AfxMessageBox(result);
}
catch (HException& e)
{
    CString str;
    str.Format(
        _T("Error=%d\r\n%s"),
        e.ErrorCode(),
        CString(e.ErrorMessage().Text()));

    AfxMessageBox(str);
}