/* Este es un nodo de ROS Indigo para guardar imagenes de /camera/depth_registered/image_rect_raw* y de /camera/rgb/color/image_rect_raw de un Turtlebot1 para luego procesarlas con otro programa. * Las de profundidad se guardan como unsigned int de 16 bits * y 1 canal, las de color se guardan como unsigned int de 8 bits en 3 canales.* Se utiliza un suscriptor sincronizado para guardar el par de imagenes que estén más* cercanas en el tiempo.* LAS IMAGENES SE GUARDAN ADONDE SE EJECUTE EL NODO.* ---------------------------------------------------------* Creado por Fabricio Emder y Pablo Aguado en el 2016 *//* This is a ROS Indigo node for saving Turtlebot images from the /camera/depth_registered/image_rect_raw* and /camera/rgb/color/image_rect_raw topics, for further processing outside of the program. * Depth images are saved as 1 channel 16 bit unsigned int PNGs (CV_16UC1), and * RGB images are saved as 3 channel 8 bit unsigned int PNGs (CV_8UC3).* A synchronized subscriber is used, for saving the pair of images that are most closer in time.* THE IMAGES ARE SAVED WHEREVER THE NODE IS RUN.* Created by Fabricio Emder and Pablo Aguado - 2016* */#include <ros/ros.h>
#include <cv_bridge/cv_bridge.h>    // OpenCV
#include <sensor_msgs/Image.h>
#include <sensor_msgs/image_encodings.h>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>#include <message_filters/subscriber.h>
#include <message_filters/synchronizer.h>/* La política de sincronización exacta NO FUNCIONA para los topics seleccionados, ya * que la Kinect o sus drivers no los están publicando con la misma marca temporal.* Ver más en http://wiki.ros.org/message_filters * * Exact sychronization policy IS NOT WORKING for the topics used, because the kinect* is not publishing them with the same timestamp. * See more in http://wiki.ros.org/message_filters  *///#define EXACT
#define APPROXIMATE#ifdef EXACT
#include <message_filters/sync_policies/exact_time.h>
#endif
#ifdef APPROXIMATE
#include <message_filters/sync_policies/approximate_time.h>
#endifusing namespace std;
//using namespace sensor_msgs;
using namespace message_filters;// Contador para la numeración de los archivos.
// Counter for filenames.
unsigned int cnt = 1;// Handler / callback
void callback( const sensor_msgs::ImageConstPtr& msg_rgb , const sensor_msgs::ImageConstPtr& msg_depth )
{//ROS_INFO_STREAM("Adentro del callback\n");
      cv_bridge::CvImagePtr img_ptr_rgb;cv_bridge::CvImagePtr img_ptr_depth;try{img_ptr_depth = cv_bridge::toCvCopy(*msg_depth, sensor_msgs::image_encodings::TYPE_16UC1);}catch (cv_bridge::Exception& e){ROS_ERROR("cv_bridge exception:  %s", e.what());return;}try{img_ptr_rgb = cv_bridge::toCvCopy(*msg_rgb, sensor_msgs::image_encodings::TYPE_8UC3);}catch (cv_bridge::Exception& e){ROS_ERROR("cv_bridge exception:  %s", e.what());return;}cv::Mat& mat_depth = img_ptr_depth->image;cv::Mat& mat_rgb = img_ptr_rgb->image;char file_rgb[100];char file_depth[100];sprintf( file_rgb, "%04d_rgb.png", cnt );sprintf( file_depth, "%04d_depth.png", cnt );vector<int> png_parameters;png_parameters.push_back( CV_IMWRITE_PNG_COMPRESSION );/* We save with no compression for faster processing.* Guardamos PNG sin compresión para menor retardo. */png_parameters.push_back( 9 ); cv::imwrite( file_rgb , mat_rgb, png_parameters );cv::imwrite( file_depth, mat_depth, png_parameters );ROS_INFO_STREAM(cnt << "\n");ROS_INFO_STREAM("Imágenes guardadas - ""Images saved\n");cnt++;}int main(int argc, char** argv)
{// Initialize the ROS system and become a node.ros::init(argc, argv, "guardar_imagenes");ros::NodeHandle nh;message_filters::Subscriber<sensor_msgs::Image> subscriber_depth( nh , "/camera/depth_registered/hw_registered/image_rect_raw" , 1 );message_filters::Subscriber<sensor_msgs::Image> subscriber_rgb( nh , "/camera/rgb/image_rect_color" , 1 );#ifdef EXACTtypedef sync_policies::ExactTime<sensor_msgs::Image, sensor_msgs::Image> MySyncPolicy;
#endif
#ifdef APPROXIMATEtypedef sync_policies::ApproximateTime<sensor_msgs::Image, sensor_msgs::Image> MySyncPolicy;
#endif// ExactTime or ApproximateTime take a queue size as its constructor argument, hence MySyncPolicy(10)Synchronizer<MySyncPolicy> sync(MySyncPolicy(10), subscriber_rgb, subscriber_depth );sync.registerCallback(boost::bind(&callback, _1, _2));while(ros::ok()){char c;ROS_INFO_STREAM("\nIngrese 'a' para guardar un par de imágenes o 'b' para guardar 300 imágenes\n""Enter 'a' to save a pair of images or 'b' to automatically save 300 images\n");cin.get(c);cin.ignore();c = tolower(c);ROS_INFO_STREAM("You entered " << c << "\n");if( c == 'a' ){/* Le damos el control a la función callback cuando haya imágenes.* We give control to the callback function.*/ros::spinOnce();    }else if( c == 'b' ){unsigned int cnt_init = cnt;while( cnt - cnt_init < 300 ){ros::spinOnce();}}else break;}ROS_INFO_STREAM("Cerrando nodo\nClosing node\n");return 0;
}

$ cd ~/test/ws/src
$ catkin_create_pkg extract_images roscpp cv_bridge sensor_msgs message_filters

$ catkin_make
$ . ~/test_ws/devel/setup.bash

$ rospack depend1 extrac_images

find_package( OpenCV REQUIRED )include_directoties( ${OpenCV_INCLUDE_DIRS} )

add_executable( extract_images src/extrac_iamges.cpp )target_link_libraries( extract_images ${OpenCV_DIRS} ${catkin_LIBRARIES} )