How to extract the world co-ordinates from a PCL.

edit

Hi,

I am currently trying to extract the world co-ordinates from a pointcloud reconstructed scene. I am currently using ROS-Hydro.

I have followed these two as my reference. http://answers.ros.org/question/98011... http://wiki.ros.org/pcl_ros

I am subscribing to the pointcloud message generated by the proc stereo_img_proc.

My code is something like this.

#include <ros/ros.h>
#include <sensor_msgs/PointCloud2.h>
#include <pcl/conversions.h> 
#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <opencv/highgui.h>
#include <cv_bridge/cv_bridge.h>
#include <iostream>
#include <pcl/io/pcd_io.h>
#include <boost/foreach.hpp>
#include <pcl/PCLPointCloud2.h>
#include <pcl_conversions/pcl_conversions.h>

void cloud_cb (const sensor_msgs::PointCloud2 pc)
{

pcl::PCLPointCloud2 pcl_pc;
pcl_conversions::toPCL(pc, pcl_pc);
pcl::PointCloud<pcl::PointXYZ> cloud;
pcl::fromPCLPointCloud2(pcl_pc, cloud);
for(int i=0;i<cloud.height;i++)  
{   
    for(int j=0; j<cloud.height;j++)    
    {       
         BOOST_FOREACH (const pcl::PointXYZ& pt, cloud.points);

            }
    }
}

I want to have the depth value for every pixel and then publish it in form of a sensor_msgs::Image message. Please guide me.

Edit:

I have made some modifications.

for(int j=0; j<cloud.points.size();j++)    
{               
    float x = cloud.points[j].x;
    float y = cloud.points[j].y;
    float z = cloud.points[j].z;

}

where x,y,z are the world co-ordinates as extracted from cloud. Will this work??