(*pt)->intensity = MAX( MAX( prev->range-(*pt)->range, succ->range-(*pt)->range), 0) * 10;

this formulator is different from the formulator described on the paper

I don't know where the MAX function is defined, would you like tell me?

I found the equation in your code to calculate the t_z is "translation[INDEX::Z] = radius3D * focal_len / radius2D - velodyne.front().z;". while in the paper it's

I can not derive the equation of either of the above. When i use the equation in your code, only the 3D points in the surface of the marker can be mapped correctly to the 2D image.So can you tell me which one is correct and better how to derive it.

Hi,
Currently, I am implementing your method to do the calibration of a RGB and depth camera in a Intel Realsense camera. I do this by following your article and the file but_velodyne/blob/master/but_calibration_camera_velodyne/src/calibration-node.cpp. Unfortunately, at the moment my estimated values for the translation in the coarse calibration are far off ([-62.17045574 21.37521807 325.99636285] while the Realsense provides me ([0.014840582385659218, 0.00022804923355579376, 0.00028663864941336215]). Do you by any chance know what can cause this? I taught, maybe it has something to do with scaling. Where in the code do you for example use the radius of, and the distance between the physical circles?

Thanks a lot!

Greetings,
Anne-Men

Hi,

I'm trying to calibrate a thermal camera with a Velodyne VPL 16. While running the coarse calibration I'm getting the following error:

[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples could be selected!

Do you have an idea of what the problem could be? thanks

Hi,

I meet a problem about message_filters, would you like give me some suggestion?
I use approximate time synchronizer with two topics (Camera and LiDAR), all nodes are compiled without any error or warning, but the callback function is not called. At the same time, it seems that the two topics are being published at the correct rate. (camera average rate: 20, LiDAR average rate: 10)
I attach the code below for help.
Thx in advance.

void Callback(const sensor_msgs::ImageConstPtr& img, const sensor_msgs::PointCloud2ConstPtr& pc2)
{
    ROS_INFO("Reached Callback");
}
int main(int argc, char** argv)
{
    ros::init(argc, argv, "camera_laser_calib");
    ros::NodeHandle nh;
    message_filters::Subscriber<PointCloud2> laser40(nh, "/pandar_points", 1);
    message_filters::Subscriber<Image> img(nh, "/camera/image_color", 1);

    typedef sync_policies::ApproximateTime<Image,PointCloud2> MySyncPolicy;
    Synchronizer<MySyncPolicy> sync(MySyncPolicy(10), img, laser40);
    sync.registerCallback(boost::bind(&Callback, _1, _2));
    
    ros::spin();

    return 0;
}

@ompugao @but-spanel @beranv @ZdenekM @nogik
command : roslaunch but_calibration_camera_velodyne calibration_coarse.launch
error:

any solution? thank you! by the way, this is the image:

Hello, I cloned but_velodyne, added it to a ROS workspace and tried to build it and got the following error:

CMake Error at but_velodyne/but_velodyne_odom/CMakeLists.txt:33 (find_package):
  By not providing "Findbut_velodyne.cmake" in CMAKE_MODULE_PATH this project
  has asked CMake to find a package configuration file provided by
  "but_velodyne", but CMake did not find one.

I am not very familiar with cmake but is cmake saying that but_velodyne_odom requires but_velodyne. If so, isn't it a circular dependency (I am building but_velodyne).

Since this is a problem I encountered after I run the code, I started a new issue.

When I run the code, I always got message
[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples cound be selected!

from some of ransac.computModel() ,ransac_l.computeModel() and ransac_sphere.computeModel(); functionn in Calibration3DMarker.cpp

I guess it is because I did not have enough data to process, so I tried to display the result of project function in Calibration3DMarker.cpp(line 30), it looks like below

I can see that only the very left is read and processed so none of the spheres can be detected. Even I tried to increase the size of Rect, it still cannot include all the data, especially the four circles in the middle of the data.

How can I process all the data from velodyne but not only the left part?

Thx!

CMakeFiles/coloring.dir/src/coloring-node.cpp.o: In function cv::String::String(char const*)': /usr/local/include/opencv2/core/cvstd.hpp:618: undefined reference to cv::String::allocate(unsigned long)'
CMakeFiles/coloring.dir/src/coloring-node.cpp.o: In function cv::String::~String()': /usr/local/include/opencv2/core/cvstd.hpp:660: undefined reference to cv::String::deallocate()'
CMakeFiles/coloring.dir/src/coloring-node.cpp.o: In function cv::Mat::Mat(int, int, int, void*, unsigned long)': /usr/local/include/opencv2/core/mat.inl.hpp:413: undefined reference to cv::error(int, cv::String const&, char const*, char const*, int)'
CMakeFiles/coloring.dir/src/Image.cpp.o: In function but_calibration_camera_velodyne::Image::Image::computeIDTEdgeImage(cv::Mat&)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Image.cpp:123: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
CMakeFiles/coloring.dir/src/Velodyne.cpp.o: In function but_calibration_camera_velodyne::Velodyne::Velodyne::project(cv::Mat, cv::Rect_<int>, pcl::PointCloud<but_calibration_camera_velodyne::Velodyne::Point>*)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Velodyne.cpp:75: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
CMakeFiles/coloring.dir/src/Velodyne.cpp.o: In function but_calibration_camera_velodyne::Velodyne::Velodyne::depthSegmentation(int)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Velodyne.cpp:225: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
collect2: error: ld returned 1 exit status
make[2]: *** [/home/zzwu/but_velo/devel/lib/but_calibration_camera_velodyne/coloring] Error 1
make[1]: *** [but_velodyne/but_calibration_camera_velodyne/CMakeFiles/coloring.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
/usr/bin/ld: warning: libboost_system.so.1.54.0, needed by /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/libpcl_common.so, may conflict with libboost_system.so.1.58.0
/usr/bin/ld: warning: libboost_thread.so.1.54.0, needed by /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/libpcl_common.so, may conflict with libboost_thread.so.1.58.0
/usr/bin/ld: warning: libboost_filesystem.so.1.54.0, needed by /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/libpcl_io.so, may conflict with libboost_filesystem.so.1.58.0
/usr/bin/ld: warning: libboost_regex.so.1.54.0, needed by /opt/ros/indigo/lib/libcv_bridge.so, may conflict with libboost_regex.so.1.58.0
CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function operator<<': /usr/local/include/opencv2/core/persistence.hpp:1076: undefined reference to cv::operator<<(cv::FileStorage&, cv::String const&)'
CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function writeAllInputs()': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/calibration-node.cpp:58: undefined reference to cv::imwrite(cv::String const&, cv::_InputArray const&, std::vector<int, std::allocator > const&)'
/home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/calibration-node.cpp:59: undefined reference to cv::FileStorage::FileStorage(cv::String const&, int, cv::String const&)' CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function operator<< cv::Mat':
/usr/local/include/opencv2/core/persistence.hpp:1064: undefined reference to cv::error(int, cv::String const&, char const*, char const*, int)' /usr/local/include/opencv2/core/persistence.hpp:1065: undefined reference to cv::write(cv::FileStorage&, cv::String const&, cv::Mat const&)'
CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function cv::String::String(char const*)': /usr/local/include/opencv2/core/cvstd.hpp:618: undefined reference to cv::String::allocate(unsigned long)'
CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function cv::String::~String()': /usr/local/include/opencv2/core/cvstd.hpp:660: undefined reference to cv::String::deallocate()'
CMakeFiles/calibration.dir/src/calibration-node.cpp.o: In function cv::Mat::Mat(int, int, int, void*, unsigned long)': /usr/local/include/opencv2/core/mat.inl.hpp:413: undefined reference to cv::error(int, cv::String const&, char const*, char const*, int)'
CMakeFiles/calibration.dir/src/Image.cpp.o: In function but_calibration_camera_velodyne::Image::Image::computeIDTEdgeImage(cv::Mat&)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Image.cpp:123: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
CMakeFiles/calibration.dir/src/Velodyne.cpp.o: In function but_calibration_camera_velodyne::Velodyne::Velodyne::project(cv::Mat, cv::Rect_<int>, pcl::PointCloud<but_calibration_camera_velodyne::Velodyne::Point>*)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Velodyne.cpp:75: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
CMakeFiles/calibration.dir/src/Velodyne.cpp.o: In function but_calibration_camera_velodyne::Velodyne::Velodyne::depthSegmentation(int)': /home/zzwu/but_velo/src/but_velodyne/but_calibration_camera_velodyne/src/Velodyne.cpp:225: undefined reference to cv::normalize(cv::_InputArray const&, cv::_InputOutputArray const&, double, double, int, int, cv::_InputArray const&)'
collect2: error: ld returned 1 exit status
make[2]: *** [/home/zzwu/but_velo/devel/lib/but_calibration_camera_velodyne/calibration] Error 1
make[1]: *** [but_velodyne/but_calibration_camera_velodyne/CMakeFiles/calibration.dir/all] Error 2
[ 59%] Linking CXX shared library /home/zzwu/but_velo/devel/lib/libbutvelo_laserscan_nodelet.so
[ 62%] Linking CXX shared library /home/zzwu/but_velo/devel/lib/libbutvelo_groundmap_nodelet.so
[ 65%] Linking CXX executable /home/zzwu/but_velo/devel/lib/but_velodyne_proc/laser_scan
[ 65%] Built target butvelo_laserscan_nodelet
[ 68%] Linking CXX executable /home/zzwu/but_velo/devel/lib/but_velodyne_proc/ground_map
[ 68%] Built target butvelo_groundmap_nodelet
[ 68%] Built target laser_scan
[ 68%] Built target ground_map
[ 71%] Linking CXX shared library /home/zzwu/but_velo/devel/lib/libbutvelo_cloudassembler_nodelet.so
[ 71%] Built target butvelo_cloudassembler_nodelet
[ 75%] Linking CXX executable /home/zzwu/but_velo/devel/lib/but_velodyne_proc/cloud_assembler
[ 75%] Built target cloud_assembler
make: *** [all] Error 2
Invoking "make -j12 -l12" failed

I'm newbie in ROS, sorry if i ask you a nonsense question.

I have hector_quadrotor project which use VLP-16 as a LiDAR sensor and it give me sensor_msgs/PointCloud2 data in /points_in topic.

I try to convert this PointCloud2 to LaserScan with but_velodyne_proc/Laserscan Node but topic /velodyne/scan and /velodyne_points return nothing with no error.

I'm not sure that i understand Laserscan Node correctly, the input of this node is topic named /points_in right?

Hi, when I tried to roslaunch calibration calibration_coarse.launch with valgrind, I got the following error and the process died. I tried to google the problem. One solution is to remove "-std=c++0x" from CMakeLists.txt but it doesn't work.

Since I am using Ubuntu 14.04, I used ROS Indigo instead of hydro. The version of pcl is 1.7. I also downloaded 1.7.1 and change CMakeLists.txt from "find_package(PCL 1.7 REQUIRED) " to find_package(PCL 1.7.1 REQUIRED) but it doesn't solve my problem.

The error is shown below,

... logging to /home/kathy/.ros/log/81df5b74-5442-11e6-9a33-bc305bcb99c7/roslaunch-kathy-PC-24948.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://kathy-PC:38970/

SUMMARY

PARAMETERS

• /but_calibration_camera_velodyne/camera_frame_topic: /cam3d/rgb/image_...
• /but_calibration_camera_velodyne/camera_info_topic: /cam3d/rgb/camera...
• /but_calibration_camera_velodyne/marker/circles_distance: 0.23
• /but_calibration_camera_velodyne/marker/circles_radius: 0.0825
• /but_calibration_camera_velodyne/velodyne_topic: /velodyne_points
• /rosdistro: indigo
• /rosversion: 1.11.20

NODES
/
calibration_coarse (but_calibration_camera_velodyne/calibration)

ROS_MASTER_URI=http://localhost:11311

core service [/rosout] found
process[calibration_coarse-1]: started with pid [24966]
==24966== Memcheck, a memory error detector
==24966== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==24966== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==24966== Command: /home/kathy/workspace/but_velodyne-hydro-devel3/but_calibration_camera_velodyne/build/devel/lib/but_calibration_camera_velodyne/calibration __name:=calibration_coarse __log:=/home/kathy/.ros/log/81df5b74-5442-11e6-9a33-bc305bcb99c7/calibration_coarse-1.log
==24966==
==24966==
==24966== Process terminating with default action of signal 11 (SIGSEGV)
==24966== Bad permissions for mapped region at address 0x5ABB28
==24966== at 0x5CAAAE0: boost::math::lanczos::lanczos_initializer<boost::math::lanczos::lanczos17m64, long double>::init::init() (in /usr/lib/libpcl_sample_consensus.so.1.7.1)
==24966== by 0x5C825CD: ??? (in /usr/lib/libpcl_sample_consensus.so.1.7.1)
==24966== by 0x4010109: call_init.part.0 (dl-init.c:78)
==24966== by 0x40101F2: call_init (dl-init.c:36)
==24966== by 0x40101F2: _dl_init (dl-init.c:126)
==24966== by 0x4001309: ??? (in /lib/x86_64-linux-gnu/ld-2.19.so)
==24966== by 0x2: ???
==24966== by 0xFFEFFFBFA: ???
==24966== by 0xFFEFFFC86: ???
==24966== by 0xFFEFFFCA1: ???
==24966==
==24966== HEAP SUMMARY:
==24966== in use at exit: 496,265 bytes in 3,512 blocks
==24966== total heap usage: 6,382 allocs, 2,870 frees, 876,519 bytes allocated
==24966==
==24966== LEAK SUMMARY:
==24966== definitely lost: 0 bytes in 0 blocks
==24966== indirectly lost: 0 bytes in 0 blocks
==24966== possibly lost: 28,993 bytes in 363 blocks
==24966== still reachable: 467,272 bytes in 3,149 blocks
==24966== suppressed: 0 bytes in 0 blocks
==24966== Rerun with --leak-check=full to see details of leaked memory
==24966==
==24966== For counts of detected and suppressed errors, rerun with: -v
==24966== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
[calibration_coarse-1] process has died [pid 24966, exit code -9, cmd valgrind /home/kathy/workspace/but_velodyne-hydro-devel3/but_calibration_camera_velodyne/build/devel/lib/but_calibration_camera_velodyne/calibration __name:=calibration_coarse __log:=/home/kathy/.ros/log/81df5b74-5442-11e6-9a33-bc305bcb99c7/calibration_coarse-1.log].
log file: /home/kathy/.ros/log/81df5b74-5442-11e6-9a33-bc305bcb99c7/calibration_coarse-1*.log
all processes on machine have died, roslaunch will exit
shutting down processing monitor...
... shutting down processing monitor complete
done

Same problem occurs when roslaunch but_calibration_camera_velodyne calibration_fine.launch

Can anyone help me? I have struggled on this problem for two days....Thank you!

@but-spanel
I believe that I am providing the right set of inputs on three topics:

1. Camera info - With the Right intrinsics and Projection matrix of Camera I am using
2. Image frame - USB Cam ROS package's Raw Image topic
3. Point Cloud from the Velodyne Driver -> / Velodyne_points
4. Circle Distance: 0.29
5. Circle Size: 0.10

But the calibration is always failing for me. Moreover, when I run the package, circles on calibration board are not found in both the image and the point cloud data. I even start receiving few errors like:

[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples could be selected!
[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples could be selected!
[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples could be selected!

I check the saved frame and pointcloud data. The image frame is clear and the pointcloud has many points.

Thanks for sharing your excellent work.
The demo in but_velodyne_lib works well on my computer, but the ros version always crashes in this line:
Eigen::Matrix4f t = registration_->runRegistration(*boost::dynamic_pointer_cast<but_velodyne::VelodynePointCloud>(pcl_input_cloud_), covariance);

I am not sure this is a bug or caused by my configuration.

The ros version demo is from
https://github.com/martin-velas/but_velodyne/blob/indigo-devel/but_velodyne_odom/demo.sh

And here is the output:

SUMMARY
========

PARAMETERS
 * /collar_line_odom/save_file: False
 * /rosdistro: indigo
 * /rosversion: 1.11.19

NODES
  /
    collar_line_odom (but_velodyne_odom/collar_line_odom)
    manager (nodelet/nodelet)

auto-starting new master
process[master]: started with pid [11425]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to ed9c810e-4270-11e6-b4e2-28d244dc300f
process[rosout-1]: started with pid [11438]
started core service [/rosout]
process[manager-2]: started with pid [11455]
[ INFO] [1467696349.056043830]: Initializing nodelet with 4 worker threads.
process[collar_line_odom-3]: started with pid [11475]
[ INFO] [1467696349.598387103]: opened file /home/libing/.ros/poses.graph
[ INFO] [1467696357.102409605]: Publishing data on topic /velodyne_points with frame_id /base_link.
[ INFO] [1467696357.797918075]: Loaded a point cloud with 124608 points (total size is 2242944) and the following channels: x y z intensity ring.
11475: Prediction:
1 0 0 0
0 1 0 0
-0 0 1 0
0 0 0 1

[collar_line_odom-3] process has died [pid 11475, exit code -11, cmd /home/libing/catkin_ws/devel/lib/but_velodyne_odom/collar_line_odom ~input/cloud:=/velodyne_points ~output/odom:=/velodyne_odom __name:=collar_line_odom __log:=/home/libing/.ros/log/ed9c810e-4270-11e6-b4e2-28d244dc300f/collar_line_odom-3.log].
log file: /home/libing/.ros/log/ed9c810e-4270-11e6-b4e2-28d244dc300f/collar_line_odom-3*.log
[ INFO] [1467696362.638622549]: Publishing data on topic /velodyne_points with frame_id /base_link.
[ INFO] [1467696363.332379942]: Loaded a point cloud with 124544 points (total size is 2241792) and the following channels: x y z intensity ring.

Can you provide some help or advice?

Thank you for excellent work. However, I am confused about some details of calibration and there is my question as follows.

1. I followed the instructions and experiment failed (detection fails). Do you have any suggestion to debug detection results with cv and pointcloud throughout visualization? I found the cv result of circles detection is commented (Image.cpp:174-197), and how about pointcloud?

2. Maybe, there is something wrong with my 3d marker. Do you have any advice upon 3d marker fabrication？

3. What is the relationship between but_calibration_camera_velodyne and but_velodyne_lib? CMakeList.txt within but_calibration_camera_velodyne doesn't contain any librarian (.so) in but_velodyne_lib. Could I compile but_calibration_camera_velodyne without but_velodyne_lib?

Thanks.

Hi,
has anyone used this tool for thermal camera - LiDAR calibration?

Hi,

I am trying to derive the extrinsic parameters by calibrating a VLP16 and a monocular camera. I had a doubt in regards to your code snippet as shown below -

  // x := x, y := -z, z := y,
  pointcloud = Velodyne::Velodyne(pc).transform(0, 0, 0, M_PI / 2, 0, 0);

Is this transformation of axis done just to bring an alignment of the camera and lidar axis? Could you please show me the orientation of the camera and lidar coordinate axis for your experimental setup.

Yet another query regarding this. In my setup, the camera is placed at a certain distance behind the LIDAR and they also are at different height planes. So does this mean I will have to consider these translations as well while transforming the axis in the start?

• topics should be in node's namespace
• configurable frames (base_link and odom are hard-coded)
• assembler parameters (buffer size, distance, filter limits, voxel-grid resolution, outlier filter, ICP disable)

Hello, I got a big problem when I catkin_make packages:

but_velodyne/but_calibration_camera_velodyne/include/but_calibration_camera_velodyne/Velodyne.h:14:10:fatla error: fatal error: velodyne_pointcloud/point_types.h: No such file or directory
#include <velodyne_pointcloud/point_types.h>
compilation terminated.
make[2]: *** [but_velodyne/but_calibration_camera_velodyne/CMakeFiles/calibration.dir/build.make:89：but_velodyne/but_calibration_camera_velodyne/CMakeFiles/calibration.dir/src/Velodyne.cpp.o] error 1

and I got to find the file in velodyne_pointcloud/include/velodyne_pointcloud/, but no files, where is wrong ?
Anyone can help me ? Thanks

Got the following error when building but_calibration_camera_velodyne

but_velodyne/but_calibration_camera_velodyne/include/but_calibration_camera_velodyne/Calibration.h:53:24: error: ‘isnan’ was not declared in this scope
return !isnan(value);

Can easily by solved with
return !std::isnan(value);

Hello,
when trying to run the calibration_coarse launch file, I get the following error message

[calibration_coarse-1] process has died [pid 12730, exit code -11, cmd /home/eaz/catkin_ws/devel/lib/but_calibration_camera_velodyne/calibration __name:=calibration_coarse __log:=/home/eaz/.ros/log/913d49d4-67d6-11e7-8057-54ee7530ff70/calibration_coarse-1.log].
log file: /home/eaz/.ros/log/913d49d4-67d6-11e7-8057-54ee7530ff70/calibration_coarse-1*.log

I have the following topics running

Published topics:
 * /webcam/webcam_image_view/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /velodyne_nodelet_manager_cloud/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /webcam/image_raw/compressed/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /velodyne_nodelet_manager_cloud/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher
 * /velodyne_nodelet_manager_driver/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /webcam/image_raw/theora/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher
 * /rosout_agg [rosgraph_msgs/Log] 1 publisher
 * /clicked_point [geometry_msgs/PointStamped] 1 publisher
 * /webcam/image_raw [sensor_msgs/Image] 1 publisher
 * /velodyne_nodelet_manager/bond [bond/Status] 3 publishers
 * /velodyne_packets [velodyne_msgs/VelodyneScan] 1 publisher
 * /velodyne_nodelet_manager_driver/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher
 * /diagnostics [diagnostic_msgs/DiagnosticArray] 1 publisher
 * /webcam/webcam_image_view/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher
 * /webcam/image_raw/compressedDepth [sensor_msgs/CompressedImage] 1 publisher
 * /webcam/camera_info [sensor_msgs/CameraInfo] 1 publisher
 * /rosout [rosgraph_msgs/Log] 8 publishers
 * /webcam/image_raw/theora [theora_image_transport/Packet] 1 publisher
 * /webcam/image_raw/compressedDepth/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher
 * /velodyne_points [sensor_msgs/PointCloud2] 1 publisher
 * /initialpose [geometry_msgs/PoseWithCovarianceStamped] 1 publisher
 * /move_base_simple/goal [geometry_msgs/PoseStamped] 1 publisher
 * /webcam/webcam_image_view/output [sensor_msgs/Image] 1 publisher
 * /webcam/image_raw/compressedDepth/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /webcam/image_raw/compressed [sensor_msgs/CompressedImage] 1 publisher
 * /webcam/image_raw/theora/parameter_updates [dynamic_reconfigure/Config] 1 publisher
 * /webcam/image_raw/compressed/parameter_descriptions [dynamic_reconfigure/ConfigDescription] 1 publisher

Subscribed topics:
 * /velodyne_nodelet_manager/bond [bond/Status] 3 subscribers
 * /webcam/image_raw [sensor_msgs/Image] 1 subscriber
 * /rosout [rosgraph_msgs/Log] 1 subscriber
 * /velodyne_points [sensor_msgs/PointCloud2] 1 subscriber
 * /tf [tf2_msgs/TFMessage] 1 subscriber
 * /tf_static [tf2_msgs/TFMessage] 1 subscriber
 * /velodyne_packets [velodyne_msgs/VelodyneScan] 1 subscriber
 * /rosout_agg [rosgraph_msgs/Log] 1 subscriber

I changed the provided config file as follows:

but_calibration_camera_velodyne:
  camera_frame_topic: /webcam/image_raw
  camera_info_topic: /webcam/camera_info
  marker: {circles_distance: 0.23, circles_radius: 0.0825}
  velodyne_topic: /velodyne_points

I am using ROS Indigo on Ubuntu 14.04 and OpenCV 2.4.

Any help is much appreciated!

Greetings,
emilaz