新接触到一个视觉库：Visual Servoing Platform
看情况这个库封装好了AprilTag识别部分
这是他们官网其中的一个例子
除了opencv和halcon又接触到一个视觉库，但是前面两个都还没搞清楚
VISP官网中AprilTag部分：
AprilTag

#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#ifdef VISP_HAVE_XML2
#include <visp3/core/vpXmlParserCamera.h>
#endif
#ifdef VISP_HAVE_V4L2
#include <visp3/sensor/vpV4l2Grabber.h>
#endif
#include <visp3/io/vpImageIo.h>
int main(int argc, const char **argv)
{
#if defined(VISP_HAVE_APRILTAG) && (defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI) || defined(VISP_HAVE_OPENCV)) &&  \
    (defined(VISP_HAVE_V4L2) || defined(VISP_HAVE_OPENCV))
  int opt_device = 0;
  vpDetectorAprilTag::vpAprilTagFamily tagFamily = vpDetectorAprilTag::TAG_36h11;
  vpDetectorAprilTag::vpPoseEstimationMethod poseEstimationMethod = vpDetectorAprilTag::HOMOGRAPHY_VIRTUAL_VS;
  double tagSize = 0.053;
  float quad_decimate = 1.0;
  int nThreads = 1;
  std::string intrinsic_file = "";
  std::string camera_name = "";
  bool display_tag = false;
  for (int i = 1; i < argc; i++) {
    if (std::string(argv[i]) == "--pose_method" && i + 1 < argc) {
      poseEstimationMethod = (vpDetectorAprilTag::vpPoseEstimationMethod)atoi(argv[i + 1]);
    } else if (std::string(argv[i]) == "--tag_size" && i + 1 < argc) {
      tagSize = atof(argv[i + 1]);
    } else if (std::string(argv[i]) == "--input" && i + 1 < argc) {
      opt_device = atoi(argv[i + 1]);
    } else if (std::string(argv[i]) == "--quad_decimate" && i + 1 < argc) {
      quad_decimate = (float)atof(argv[i + 1]);
    } else if (std::string(argv[i]) == "--nthreads" && i + 1 < argc) {
      nThreads = atoi(argv[i + 1]);
    } else if (std::string(argv[i]) == "--intrinsic" && i + 1 < argc) {
      intrinsic_file = std::string(argv[i + 1]);
    } else if (std::string(argv[i]) == "--camera_name" && i + 1 < argc) {
      camera_name = std::string(argv[i + 1]);
    } else if (std::string(argv[i]) == "--display_tag") {
      display_tag = true;
    } else if (std::string(argv[i]) == "--tag_family" && i + 1 < argc) {
      tagFamily = (vpDetectorAprilTag::vpAprilTagFamily)atoi(argv[i + 1]);
    } else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
      std::cout << "Usage: " << argv[0]
                << " [--input <camera input>] [--tag_size <tag_size in m>]"
                   " [--quad_decimate <quad_decimate>] [--nthreads <nb>]"
                   " [--intrinsic <intrinsic file>] [--camera_name <camera name>]"
                   " [--pose_method <method> (0: HOMOGRAPHY_VIRTUAL_VS, 1: "
                   "DEMENTHON_VIRTUAL_VS,"
                   " 2: LAGRANGE_VIRTUAL_VS, 3: BEST_RESIDUAL_VIRTUAL_VS)]"
                   " [--tag_family <family> (0: TAG_36h11, 1: TAG_36h10, 2: "
                   "TAG_36ARTOOLKIT,"
                   " 3: TAG_25h9, 4: TAG_25h7, 5: TAG_16h5)]"
                   " [--display_tag] [--help]"
                << std::endl;
      return EXIT_SUCCESS;
    }
  }
  vpCameraParameters cam;
  cam.initPersProjWithoutDistortion(615.1674805, 615.1675415, 312.1889954, 243.4373779);
#ifdef VISP_HAVE_XML2
  vpXmlParserCamera parser;
  if (!intrinsic_file.empty() && !camera_name.empty())
    parser.parse(cam, intrinsic_file, camera_name, vpCameraParameters::perspectiveProjWithoutDistortion);
#endif
  std::cout << "cam:\n" << cam << std::endl;
  std::cout << "poseEstimationMethod: " << poseEstimationMethod << std::endl;
  std::cout << "tagFamily: " << tagFamily << std::endl;
  try {
    vpImage<unsigned char> I;
#if defined(VISP_HAVE_V4L2)
    vpV4l2Grabber g;
    std::ostringstream device;
    device << "/dev/video" << opt_device;
    g.setDevice(device.str());
    g.setScale(1);
    g.acquire(I);
#elif defined(VISP_HAVE_OPENCV)
    cv::VideoCapture cap(opt_device); // open the default camera
    if (!cap.isOpened()) {            // check if we succeeded
      std::cout << "Failed to open the camera" << std::endl;
      return EXIT_FAILURE;
    }
    cv::Mat frame;
    cap >> frame; // get a new frame from camera
    vpImageConvert::convert(frame, I);
#endif
#ifdef VISP_HAVE_X11
    vpDisplayX d(I);
#elif defined(VISP_HAVE_GDI)
    vpDisplayGDI d(I);
#elif defined(VISP_HAVE_OPENCV)
    vpDisplayOpenCV d(I);
#endif
    vpDetectorBase *detector = new vpDetectorAprilTag(tagFamily);
    dynamic_cast<vpDetectorAprilTag *>(detector)->setAprilTagQuadDecimate(quad_decimate);
    dynamic_cast<vpDetectorAprilTag *>(detector)->setAprilTagPoseEstimationMethod(poseEstimationMethod);
    dynamic_cast<vpDetectorAprilTag *>(detector)->setAprilTagNbThreads(nThreads);
    dynamic_cast<vpDetectorAprilTag *>(detector)->setDisplayTag(display_tag);
    std::vector<double> time_vec;
    for (;;) {
#if defined(VISP_HAVE_V4L2)
      g.acquire(I);
#elif defined(VISP_HAVE_OPENCV)
      cap >> frame; // get a new frame from camera
      vpImageConvert::convert(frame, I);
#endif
      vpDisplay::display(I);
      double t = vpTime::measureTimeMs();
      std::vector<vpHomogeneousMatrix> cMo_vec;
      dynamic_cast<vpDetectorAprilTag *>(detector)->detect(I, tagSize, cam, cMo_vec);
      t = vpTime::measureTimeMs() - t;
      time_vec.push_back(t);
      std::stringstream ss;
      ss << "Detection time: " << t << " ms for " << detector->getNbObjects() << " tags";
      vpDisplay::displayText(I, 40, 20, ss.str(), vpColor::red);
      for (size_t i = 0; i < cMo_vec.size(); i++) {
        vpDisplay::displayFrame(I, cMo_vec[i], cam, tagSize / 2, vpColor::none, 3);
      }
      vpDisplay::displayText(I, 20, 20, "Click to quit.", vpColor::red);
      vpDisplay::flush(I);
      if (vpDisplay::getClick(I, false))
        break;
    }
    std::cout << "Benchmark computation time" << std::endl;
    std::cout << "Mean / Median / Std: " << vpMath::getMean(time_vec) << " ms"
              << " ; " << vpMath::getMedian(time_vec) << " ms"
              << " ; " << vpMath::getStdev(time_vec) << " ms" << std::endl;
    delete detector;
  } catch (const vpException &e) {
    std::cerr << "Catch an exception: " << e.getMessage() << std::endl;
  }
  return EXIT_SUCCESS;
#else
  (void)argc;
  (void)argv;
  return 0;
#endif
}