PCL关键点（1）

#include <iostream>
#include <boost/thread/thread.hpp>
#include <pcl/range_image/range_image.h>
#include <pcl/io/pcd_io.h>
#include <pcl/visualization/range_image_visualizer.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/features/range_image_border_extractor.h>
#include <pcl/keypoints/narf_keypoint.h>
#include <pcl/features/narf_descriptor.h>
#include <pcl/console/parse.h>

typedef pcl::PointXYZ PointType;
float angular_resolution = 0.5f; //angular_resolution为模拟的深度传感器的角度分辨率，即深度图像中一个像素对应的角度大小
float support_size = 0.2f;                 //点云大小的设置
pcl::RangeImage::CoordinateFrame coordinate_frame = pcl::RangeImage::CAMERA_FRAME;     //设置坐标系
bool setUnseenToMaxRange = false;
bool rotation_invariant = true;
void printUsage (const char* progName)
{
 std::cout << "\n\nUsage: "<<progName<<" [options] <scene.pcd>\n\n"
           << "Options:\n"
           << "-------------------------------------------\n"
           << "-r <float>   angular resolution in degrees (default "<<angular_resolution<<")\n" << "-c <int>     coordinate frame (default "<< (int)coordinate_frame<<")\n"
           << "-m           Treat all unseen points to max range\n"
           << "-s <float>   support size for the interest points (diameter of the used sphere - ""default "<<support_size<<")\n"
           << "-o <0/1>     switch rotational invariant version of the feature on/off"
           <<               " (default "<< (int)rotation_invariant<<")\n"
           << "-h           this help\n"
           << "\n\n";
}void setViewerPose (pcl::visualization::PCLVisualizer& viewer, const Eigen::Affine3f& viewer_pose)  //设置视口的位姿{
 Eigen::Vector3f pos_vector = viewer_pose * Eigen::Vector3f (0, 0, 0);  
 //视口的原点pos_vector
 Eigen::Vector3f look_at_vector = viewer_pose.rotation () * Eigen::Vector3f (0, 0, 1) + pos_vector;  //旋转+平移look_at_vector
 Eigen::Vector3f up_vector = viewer_pose.rotation () * Eigen::Vector3f (0, -1, 0);   //up_vector
 viewer.setCameraPosition (pos_vector[0], pos_vector[1], pos_vector[2],    look_at_vector[0], look_at_vector[1], look_at_vector[2], up_vector[0], up_vector[1], up_vector[2]);
}
 int main (int argc, char** argv)
{  
 if (pcl::console::find_argument (argc, argv, "-h") >= 0)
 {
   printUsage (argv[0]);    return 0;
 }  if (pcl::console::find_argument (argc, argv, "-m") >= 0)
 {
   setUnseenToMaxRange = true;
   cout << "Setting unseen values in range image to maximum range readings.\n";
 }  if (pcl::console::parse (argc, argv, "-o", rotation_invariant) >= 0)
   cout << "Switching rotation invariant feature version "<< (rotation_invariant ? "on" : "off")<<".\n";  int tmp_coordinate_frame;  if (pcl::console::parse (argc, argv, "-c", tmp_coordinate_frame) >= 0)
 {
   coordinate_frame = pcl::RangeImage::CoordinateFrame (tmp_coordinate_frame);
   cout << "Using coordinate frame "<< (int)coordinate_frame<<".\n";
 }  if (pcl::console::parse (argc, argv, "-s", support_size) >= 0)
   cout << "Setting support size to "<<support_size<<".\n";  if (pcl::console::parse (argc, argv, "-r", angular_resolution) >= 0)
   cout << "Setting angular resolution to "<<angular_resolution<<"deg.\n";
 angular_resolution = pcl::deg2rad (angular_resolution);  
 // -Read pcd file or create example point cloud if not given--  // 
 pcl::PointCloud<PointType>::Ptr point_cloud_ptr (new pcl::PointCloud<PointType>);
 pcl::PointCloud<PointType>& point_cloud = *point_cloud_ptr;
 pcl::PointCloud<pcl::PointWithViewpoint> far_ranges;
 Eigen::Affine3f scene_sensor_pose (Eigen::Affine3f::Identity ());
 std::vector<int> pcd_filename_indices = pcl::console::parse_file_extension_argument (argc, argv, "pcd");  if (!pcd_filename_indices.empty ())
 {
   std::string filename = argv[pcd_filename_indices[0]];    if (pcl::io::loadPCDFile (filename, point_cloud) == -1)
   {
     cerr << "Was not able to open file \""<<filename<<"\".\n";
     printUsage (argv[0]);      return 0;
   }

   scene_sensor_pose = Eigen::Affine3f (Eigen::Translation3f (point_cloud.sensor_origin_[0],  point_cloud.sensor_origin_[1],point_cloud.sensor_origin_[2])) * Eigen::Affine3f (point_cloud.sensor_orientation_);
   std::string far_ranges_filename = pcl::getFilenameWithoutExtension (filename)+"_far_ranges.pcd";    if (pcl::io::loadPCDFile (far_ranges_filename.c_str (), far_ranges) == -1)
     std::cout << "Far ranges file \""<<far_ranges_filename<<"\" does not exists.\n";
 }  else
 {
   setUnseenToMaxRange = true;
   cout << "\nNo *.pcd file given => Genarating example point cloud.\n\n";    for (float x=-0.5f; x<=0.5f; x+=0.01f)
   {      for (float y=-0.5f; y<=0.5f; y+=0.01f)
     {
       PointType point;  point.x = x;  point.y = y;  point.z = 2.0f - y;
       point_cloud.points.push_back (point);
     }
   }
   point_cloud.width = (int) point_cloud.points.size ();  point_cloud.height = 1;
 }  
 // -----Create RangeImage from the PointCloud-----  // 
 float noise_level = 0.0;  float min_range = 0.0f;  int border_size = 1;
 boost::shared_ptr<pcl::RangeImage> range_image_ptr (new pcl::RangeImage);
 pcl::RangeImage& range_image = *range_image_ptr;  
 range_image.createFromPointCloud (point_cloud, angular_resolution, pcl::deg2rad (360.0f), pcl::deg2rad (180.0f),
                                  scene_sensor_pose, coordinate_frame, noise_level, min_range, border_size);
 range_image.integrateFarRanges (far_ranges);  if (setUnseenToMaxRange)
   range_image.setUnseenToMaxRange ();    // -----Open 3D viewer and add point cloud-----  //
 pcl::visualization::PCLVisualizer viewer ("3D Viewer");
 viewer.setBackgroundColor (1, 1, 1);
 pcl::visualization::PointCloudColorHandlerCustom<pcl::PointWithRange> range_image_color_handler (range_image_ptr, 0, 0, 0);
 viewer.addPointCloud (range_image_ptr, range_image_color_handler, "range image");
 viewer.setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, "range image"); 
  //viewer.addCoordinateSystem (1.0f, "global"); 
//PointCloudColorHandlerCustom<PointType> point_cloud_color_handler (point_cloud_ptr, 150, 150, 150); 
//viewer.addPointCloud (point_cloud_ptr, point_cloud_color_handler, "original point cloud");  
  viewer.initCameraParameters ();
 setViewerPose (viewer, range_image.getTransformationToWorldSystem ());   // -----Show range image-----  //
 pcl::visualization::RangeImageVisualizer range_image_widget ("Range image");
 range_image_widget.showRangeImage (range_image); 
   /* 创建RangeImageBorderExtractor对象，它是用来进行边缘提取的，因为NARF的第一步就是需要探测出深度图像的边缘*/ // -----Extract NARF keypoints-----  // 
 pcl::RangeImageBorderExtractor range_image_border_extractor;   //用来提取边缘
 pcl::NarfKeypoint narf_keypoint_detector;      //用来检测关键点
 narf_keypoint_detector.setRangeImageBorderExtractor (&range_image_border_extractor);   //  narf_keypoint_detector.setRangeImage (&range_image);
 narf_keypoint_detector.getParameters ().support_size = support_size;    //设置NARF的参数  
 pcl::PointCloud<int> keypoint_indices;
 narf_keypoint_detector.compute (keypoint_indices);
 std::cout << "Found "<<keypoint_indices.points.size ()<<" key points.\n"; // -----Show keypoints in 3D viewer-----  // 
 pcl::PointCloud<pcl::PointXYZ>::Ptr keypoints_ptr (new pcl::PointCloud<pcl::PointXYZ>);
 pcl::PointCloud<pcl::PointXYZ>& keypoints = *keypoints_ptr;
 keypoints.points.resize (keypoint_indices.points.size ());  for (size_t i=0; i<keypoint_indices.points.size (); ++i)
   keypoints.points[i].getVector3fMap () = range_image.points[keypoint_indices.points[i]].getVector3fMap ();
 pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> keypoints_color_handler (keypoints_ptr, 0, 255, 0);
 viewer.addPointCloud<pcl::PointXYZ> (keypoints_ptr, keypoints_color_handler, "keypoints");
 viewer.setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 7, "keypoints");   // -----Extract NARF descriptors for interest points-----  // 
 std::vector<int> keypoint_indices2;
 keypoint_indices2.resize (keypoint_indices.points.size ());  for (unsigned int i=0; i<keypoint_indices.size (); ++i) // This step is necessary to get the right vector type
   keypoint_indices2[i]=keypoint_indices.points[i];
 pcl::NarfDescriptor narf_descriptor (&range_image, &keypoint_indices2);
 narf_descriptor.getParameters ().support_size = support_size;
 narf_descriptor.getParameters ().rotation_invariant = rotation_invariant;
 pcl::PointCloud<pcl::Narf36> narf_descriptors;
 narf_descriptor.compute (narf_descriptors);
 cout << "Extracted "<<narf_descriptors.size ()<<" descriptors for "
                     <<keypoint_indices.points.size ()<< " keypoints.\n";
 while (!viewer.wasStopped ())
 {
   range_image_widget.spinOnce ();  // process GUI events    viewer.spinOnce ();
   pcl_sleep(0.01);
 }
}