text: #include <memory>
  
  #include <opencv2/highgui/highgui.hpp>
  #include <opencv2/imgcodecs.hpp>
  #include <opencv2/imgproc.hpp>
  
  #include "aos/init.h"
  #include "aos/time/time.h"
  #include "y2020/vision/sift/fast_gaussian.h"
  #include "glog/logging.h"
  #include "y2020/vision/sift/sift971.h"
  
  DEFINE_string(image, "", "Image to test with");
  
  int main(int argc, char **argv) {
    aos::InitGoogle(&argc, &argv);
  
    cv::setNumThreads	(4);
  
    const cv::Mat raw_image = cv::imread(FLAGS_image);
    CHECK(!raw_image.empty()) << ": Failed to read: " << FLAGS_image;
    CHECK_EQ(CV_8UC3, raw_image.type());
  #if 0
    cv::Mat color_image;
    raw_image.convertTo(color_image, CV_32F, 1.0/255.0);
    cv::Mat image;
    cv::cvtColor(color_image, image, cv::COLOR_BGR2GRAY);
  #else
    cv::Mat gray_image;
    cv::cvtColor(raw_image, gray_image, cv::COLOR_BGR2GRAY);
    cv::Mat float_image;
  #if 0
    gray_image.convertTo(float_image, CV_32F, 0.00390625);
  #else
    float_image = gray_image;
  #endif
    cv::Mat image;
    cv::resize(float_image, image, cv::Size(1280, 720), 0, 0, cv::INTER_AREA);
  #endif
  #if 0
  #if 0
    cv::namedWindow("source", cv::WINDOW_AUTOSIZE);
    cv::imshow("source", raw_image);
    cv::namedWindow("converted", cv::WINDOW_AUTOSIZE);
    cv::imshow("converted", image);
  #endif
  
    cv::Mat slow_blurred, fast_blurred;
    const double sigma = 3.0900155872895909;
    cv::GaussianBlur(image, slow_blurred, cv::Size(9, 9), sigma, sigma);
    frc971::vision::FastGaussian(image, &fast_blurred, sigma);
    cv::namedWindow("slow", cv::WINDOW_AUTOSIZE);
    cv::imshow("slow", slow_blurred);
    cv::namedWindow("fast", cv::WINDOW_AUTOSIZE);
    cv::imshow("fast", fast_blurred);
    cv::waitKey(0);
    return 0;
  #endif
  
    LOG(INFO);
    std::unique_ptr<frc971::vision::SIFT971_Impl> sift(new frc971::vision::SIFT971_Impl());
    std::vector<cv::KeyPoint> keypoints;
    cv::Mat descriptors;
    LOG(INFO) << "detectAndCompute on " << image.rows << "x" << image.cols;
    sift->detectAndCompute(image, cv::noArray(), keypoints, descriptors);
    LOG(INFO);
  
  #if 0
    return 0;
  #endif
  
    static constexpr int kIterations = 40;
    const auto start = aos::monotonic_clock::now();
    for (int i = 0; i < kIterations; ++i) {
      keypoints.clear();
      descriptors.release();
      sift->detectAndCompute(image, cv::noArray(), keypoints, descriptors);
    }
    const auto end = aos::monotonic_clock::now();
    LOG(INFO)
        << "Took: "
        << (std::chrono::duration<double>(end - start) / kIterations).count();
    // Should be ~352 for FRC-Image4-cleaned.png downscaled to 640x360.
    // 376 in DoG_TYPE_SHORT mode.
    // 344 now with 1280x720 non-upscaled.
    LOG(INFO) << "found " << keypoints.size() << " and " << descriptors.size();
  }
  