hand_control/src/filter.cpp

/* Copyright © 2015 CentraleSupélec
 * 
 * This file is part of Hand Control.
 * 
 * Hand Control is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Hand Control is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Hand Control.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <ros/ros.h>
#include <pcl_ros/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/tracking/impl/hsv_color_coherence.hpp>
#include <assert.h>
#include <dynamic_reconfigure/server.h>
#include <hand_control/FilterConfig.h>


typedef pcl::PointXYZRGB Point;
typedef pcl::PointCloud<Point> PointCloud;

class Callback {
  public:
    void
    callback(const PointCloud::ConstPtr& msg)
    // handles and filters the received PointCloud and
    // publishes the filtered PointCloud
    {
      PointCloud::Ptr pcl(new PointCloud());
      copy_info(msg, pcl); // copy the header
      BOOST_FOREACH (const Point& pt, msg->points)
      {
        float hue_dist, sat, val;
        hdist_s_v(pt, hue_dist, sat, val);
        if (pt.z < z_max and hue_dist < delta_hue and sat < sat_max and sat > sat_min and val < val_max and val > val_min)
          pcl->push_back(pt);
      }
      pcl->height = 1;
      pcl->width = pcl->points.size();
      publisher.publish(pcl);
    }

    Callback(const ros::Publisher& pub)
    : publisher(pub), z_max(90.), hue(0.), delta_hue(20.),  sat_min(0.3), sat_max(1.), val_min(0.3), val_max(1.)
    {}

  void
  reconfigure(const hand_control::FilterConfig& c, const uint32_t& level)
  // updates the parameters
  { 
    z_max = c.z_max;
    hue = c.hue;
    delta_hue = c.delta_hue;
    val_min = c.val_min;
    val_max = c.val_max;
    sat_min = c.sat_min;
    sat_max = c.sat_max;
  }

  private:
    ros::Publisher publisher;
    float z_max, hue, delta_hue, val_min, val_max, sat_min, sat_max;

    inline
    void
    copy_info(const PointCloud::ConstPtr& a,
              PointCloud::Ptr& b)
    // copy the header info (useful in order to use rviz)
    {
      b->header = a->header;
      b->sensor_origin_ = a->sensor_origin_;
      b->sensor_orientation_ = a->sensor_orientation_;
      b->is_dense = a->is_dense;
    }

    inline
    void
    hdist_s_v(const Point& pt, float& h_dist, float& s, float& v)
    // calculate the distance from the wished hue, the saturation and the value 
    // of the point
    {
      float h, diff1, diff2;
      pcl::tracking::RGB2HSV(pt.r, pt.g, pt.b, h, s, v);
      h *= 360.0f ;
      diff1 = std::fabs(h - hue);
      // hue is periodic
      if (h < hue)
        diff2 = std::fabs(360.0f + h - hue);
      else
        diff2 = std::fabs(360.0f + hue - h);
      h_dist = std::min(diff1, diff2);
    }
};

int
main(int argc, char** argv)
{
  ros::init(argc, argv, "filter");
  ros::NodeHandle node("filter");
  ros::Publisher  publisher = node.advertise<PointCloud>("output", 1);
  Callback my_callback(publisher);
  ros::Subscriber subscriber = node.subscribe<PointCloud>("input", 1, &Callback::callback, &my_callback);

  // sets up dynamic_reconfigure
  dynamic_reconfigure::Server<hand_control::FilterConfig> server;
  dynamic_reconfigure::Server<hand_control::FilterConfig>::CallbackType f;
  f = boost::bind(&Callback::reconfigure, &my_callback, _1, _2);
  server.setCallback(f);

  // begins working
  ROS_INFO("node started");
  ros::spin();
  ROS_INFO("exit");
  return 0;
}