Point Cloud Library (PCL)  1.3.1
conversions.h
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00034  * $Id: conversions.h 3180 2011-11-17 16:25:52Z mdixon $
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00037 
00038 #ifndef PCL_ROS_CONVERSIONS_H_ 
00039 #define PCL_ROS_CONVERSIONS_H_
00040 
00041 #include <sensor_msgs/PointField.h>
00042 #include <sensor_msgs/PointCloud2.h>
00043 #include <sensor_msgs/Image.h>
00044 #include "pcl/point_cloud.h"
00045 #include "pcl/ros/point_traits.h"
00046 #include "pcl/ros/for_each_type.h"
00047 #include "pcl/exceptions.h"
00048 #include <boost/foreach.hpp>
00049 
00050 namespace pcl
00051 {
00052   namespace detail
00053   {
00054     // For converting template point cloud to message.
00055     template<typename PointT>
00056     struct FieldAdder
00057     {
00058       FieldAdder (std::vector<sensor_msgs::PointField>& fields) : fields_ (fields) {};
00059       
00060       template<typename U> void operator() ()
00061       {
00062         sensor_msgs::PointField f;
00063         f.name = traits::name<PointT, U>::value;
00064         f.offset = traits::offset<PointT, U>::value;
00065         f.datatype = traits::datatype<PointT, U>::value;
00066         f.count = traits::datatype<PointT, U>::size;
00067         fields_.push_back (f);
00068       }
00069 
00070       std::vector<sensor_msgs::PointField>& fields_;
00071     };
00072 
00073     // For converting message to template point cloud.
00074     template<typename PointT>
00075     struct FieldMapper
00076     {
00077       FieldMapper (const std::vector<sensor_msgs::PointField>& fields,
00078                    std::vector<FieldMapping>& map)
00079         : fields_ (fields), map_ (map)
00080       {
00081       }
00082       
00083       template<typename Tag> void operator() ()
00084       {
00085         const char* name = traits::name<PointT, Tag>::value;
00086         BOOST_FOREACH(const sensor_msgs::PointField& field, fields_)
00087         {
00088           if (field.name == name)
00089           {
00090             typedef traits::datatype<PointT, Tag> Data;
00091             assert (Data::value == field.datatype);
00092             //@todo: Talk to Patrick about this
00093             //assert (Data::size  == field.count);
00094             
00095             FieldMapping mapping;
00096             mapping.serialized_offset = field.offset;
00097             mapping.struct_offset = traits::offset<PointT, Tag>::value;
00098             mapping.size = sizeof (typename Data::type);
00099             map_.push_back (mapping);
00100             return;
00101           }
00102         }
00103         // didn't find it...
00104         std::stringstream ss;
00105         ss << "Failed to find a field named: '" << name
00106            << "'. Cannot convert message to PCL type.";
00107         PCL_ERROR ("%s\n", ss.str().c_str());
00108         throw pcl::InvalidConversionException(ss.str());
00109       }
00110 
00111       const std::vector<sensor_msgs::PointField>& fields_;
00112       std::vector<FieldMapping>& map_;
00113     };
00114 
00115     inline bool fieldOrdering(const FieldMapping& a, const FieldMapping& b)
00116     {
00117       return a.serialized_offset < b.serialized_offset;
00118     }
00119 
00120   } //namespace detail
00121 
00122   template<typename PointT>
00123   void createMapping (const std::vector<sensor_msgs::PointField>& msg_fields, MsgFieldMap& field_map)
00124   {
00125     // Create initial 1-1 mapping between serialized data segments and struct fields
00126     detail::FieldMapper<PointT> mapper (msg_fields, field_map);
00127     for_each_type< typename traits::fieldList<PointT>::type > (mapper);
00128 
00129     // Coalesce adjacent fields into single memcpy's where possible
00130     if (field_map.size() > 1)
00131     {
00132       std::sort(field_map.begin(), field_map.end(), detail::fieldOrdering);
00133       MsgFieldMap::iterator i = field_map.begin(), j = i + 1;
00134       while (j != field_map.end())
00135       {
00136         // This check is designed to permit padding between adjacent fields.
00139         if (j->serialized_offset - i->serialized_offset == j->struct_offset - i->struct_offset)
00140         {
00141           i->size += (j->struct_offset + j->size) - (i->struct_offset + i->size);
00142           j = field_map.erase(j);
00143         }
00144         else
00145         {
00146           ++i;
00147           ++j;
00148         }
00149       }
00150     }
00151   }
00152 
00153   template<typename PointT>  
00154   void fromROSMsg (const sensor_msgs::PointCloud2& msg, pcl::PointCloud<PointT>& cloud,
00155                    const MsgFieldMap& field_map)
00156   {
00157     // Copy info fields
00158     cloud.header   = msg.header;
00159     cloud.width    = msg.width;
00160     cloud.height   = msg.height;
00161     cloud.is_dense = msg.is_dense == 1;
00162 
00163     // Copy point data
00164     uint32_t num_points = msg.width * msg.height;
00165     cloud.points.resize (num_points);
00166     uint8_t* cloud_data = reinterpret_cast<uint8_t*>(&cloud.points[0]);
00167 
00168     // Check if we can copy adjacent points in a single memcpy
00169     if (field_map.size() == 1 &&
00170         field_map[0].serialized_offset == 0 &&
00171         field_map[0].struct_offset == 0 &&
00172         msg.point_step == sizeof(PointT))
00173     {
00174       uint32_t cloud_row_step = sizeof(PointT) * cloud.width;
00175       const uint8_t* msg_data = &msg.data[0];
00176       // Should usually be able to copy all rows at once
00177       if (msg.row_step == cloud_row_step)
00178       {
00179         memcpy (cloud_data, msg_data, msg.data.size());
00180       }
00181       else
00182       {
00183         for (uint32_t i = 0; i < msg.height;
00184              ++i, cloud_data += cloud_row_step, msg_data += msg.row_step)
00185           memcpy (cloud_data, msg_data, cloud_row_step);
00186       }
00187     }
00188     else
00189     {
00190       // If not, memcpy each group of contiguous fields separately
00191       for (uint32_t row = 0; row < msg.height; ++row)
00192       {
00193         const uint8_t* row_data = &msg.data[row * msg.row_step];
00194         for (uint32_t col = 0; col < msg.width; ++col)
00195         {
00196           const uint8_t* msg_data = row_data + col * msg.point_step;
00197           BOOST_FOREACH (const detail::FieldMapping& mapping, field_map)
00198           {
00199             memcpy (cloud_data + mapping.struct_offset, msg_data + mapping.serialized_offset, mapping.size);
00200           }
00201           cloud_data += sizeof (PointT);
00202         }
00203       }
00204     }
00205   }
00206 
00207   template<typename PointT>  
00208   void fromROSMsg (const sensor_msgs::PointCloud2& msg, pcl::PointCloud<PointT>& cloud)
00209   {
00210     MsgFieldMap field_map;
00211     createMapping<PointT> (msg.fields, field_map);
00212     fromROSMsg (msg, cloud, field_map);
00213   }
00214 
00215   template<typename PointT>
00216   void toROSMsg (const pcl::PointCloud<PointT>& cloud, sensor_msgs::PointCloud2& msg)
00217   {
00218     // Ease the user's burden on specifying width/height for unorganized datasets
00219     if (cloud.width == 0 && cloud.height == 0)
00220     {
00221       msg.width  = (uint32_t) cloud.points.size ();
00222       msg.height = 1;
00223     }
00224     else
00225     {
00226       assert (cloud.points.size () == cloud.width * cloud.height);
00227       msg.height = cloud.height;
00228       msg.width  = cloud.width;
00229     }
00230 
00231     // Fill point cloud binary data (padding and all)
00232     size_t data_size = sizeof (PointT) * cloud.points.size ();
00233     msg.data.resize (data_size);
00234     memcpy (&msg.data[0], &cloud.points[0], data_size);
00235 
00236     // Fill fields metadata
00237     msg.fields.clear ();
00238     for_each_type< typename traits::fieldList<PointT>::type > (detail::FieldAdder<PointT>(msg.fields));
00239 
00240     msg.header     = cloud.header;
00241     msg.point_step = sizeof (PointT);
00242     msg.row_step   = sizeof (PointT) * msg.width;
00243     msg.is_dense   = cloud.is_dense;
00245   }
00246 
00253   template<typename CloudT> void
00254   toROSMsg(const CloudT& cloud, sensor_msgs::Image& msg)
00255   {
00256     // Ease the user's burden on specifying width/height for unorganized datasets
00257     if (cloud.width == 0 && cloud.height == 0)
00258       throw std::runtime_error("Needs to be a dense like cloud!!");
00259     else
00260     {
00261       if(cloud.points.size () != cloud.width * cloud.height){
00262         throw std::runtime_error("The width and height do not match the cloud size!");
00263       }
00264       msg.height = cloud.height;
00265       msg.width = cloud.width;
00266     }
00267 
00268     // ensor_msgs::image_encodings::BGR8;
00269     msg.encoding = "bgr8";
00270     msg.step = msg.width * sizeof(uint8_t) * 3;
00271     msg.data.resize(msg.step * msg.height);
00272     for (size_t y = 0; y < cloud.height; y++)
00273     {
00274       for (size_t x = 0; x < cloud.width; x++)
00275       {
00276         uint8_t * pixel = &(msg.data[y * msg.step + x * 3]);
00277         memcpy(pixel, &cloud (x, y).rgb, 3 * sizeof(uint8_t));
00278       }
00279     }
00280   }
00281 
00287   inline void
00288   toROSMsg (const sensor_msgs::PointCloud2& cloud, sensor_msgs::Image& msg)
00289   {
00290     int rgb_index = -1;
00291     // Get the index we need
00292     for (size_t d = 0; d < cloud.fields.size (); ++d)
00293       if (cloud.fields[d].name == "rgb")
00294       {
00295         rgb_index = (int) d;
00296         break;
00297       }
00298 
00299     if(rgb_index == -1)
00300       throw std::runtime_error ("No rgb field!!");
00301     if (cloud.width == 0 && cloud.height == 0)
00302       throw std::runtime_error ("Needs to be a dense like cloud!!");
00303     else
00304     {
00305       msg.height = cloud.height;
00306       msg.width = cloud.width;
00307     }
00308     int rgb_offset = cloud.fields[rgb_index].offset;
00309     int point_step = cloud.point_step;
00310 
00311     // sensor_msgs::image_encodings::BGR8;
00312     msg.encoding = "bgr8";
00313     msg.step = msg.width * sizeof(uint8_t) * 3;
00314     msg.data.resize (msg.step * msg.height);
00315 
00316     for (size_t y = 0; y < cloud.height; y++)
00317     {
00318       for (size_t x = 0; x < cloud.width; x++, rgb_offset += point_step)
00319       {
00320         uint8_t * pixel = &(msg.data[y * msg.step + x * 3]);
00321         memcpy (pixel, &(cloud.data[rgb_offset]), 3 * sizeof (uint8_t));
00322       }
00323     }
00324   }
00325 }
00326 
00327 #endif  //#ifndef PCL_ROS_CONVERSIONS_H_
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