OpenCVSharp 4.5 特征检测

用 OpenCVSharp 4.5 跑一遍 OpenCV 官方教程。

原 OpenCV 官方教程链接：OpenCV: Feature Detection

核心函数：

1. cv::FeatureDetector
2. cv::xfeatures2d::SURF
3. cv::xfeatures2d::SURF::detect
4. cv::drawKeypoints

using System;
using OpenCvSharp;
using OpenCvSharp.XFeatures2D;

namespace ConsoleApp1
{
    class tutor