using calibrationdata.tar.gz file in a launch file [closed]

asked 2013-05-15 10:39:36 -0500

ZoltanS gravatar image

updated 2013-05-15 11:03:22 -0500

I calibrated my 2 usb cameras (using usb_cam driver) with the camera_calibration tool in stereo vision. As a result I got a /tmp/calibrationdata.tar.gz file. Since I couldn't use the commit function of the calibration tool, all I have is this file. How can I use it?

What I tried:

  • extracted the ost.txt file from the calibrationdata.tar.gz
  • converted it to yaml format using the camera_calibration_parsers tool (2x for left and right camera)
  • in the camera launch file included the following line for both left and right camera:

<param name="left/camera_info_url" type="string" value="file://left_camera_calibration.yaml" />

The camera launch file is as follows:

<launch>
  <group ns="stereo">
    <node name="left" pkg="usb_cam" type="usb_cam_node" output="screen" >
        <param name="video_device" value="/dev/video1" />
        <param name="image_width" value="640" />
        <param name="image_height" value="480" />
        <param name="pixel_format" value="mjpeg" />
        <param name="camera_frame_id" value="left" />
        <param name="io_method" value="mmap"/>      
        <rosparam file="example-left.yaml"/>    
        <param name="left/camera_info_url" type="string" value="file://left_camera_calibration.yaml" />
    </node>

    <node name="right" pkg="usb_cam" type="usb_cam_node" output="screen" >
        <param name="video_device" value="/dev/video2" />
        <param name="image_width" value="640" />
        <param name="image_height" value="480" />
        <param name="pixel_format" value="mjpeg" />
        <param name="camera_frame_id" value="right" />
        <param name="io_method" value="mmap"/>          
        <rosparam file="example-right.yaml"/>   
        <param name="right/camera_info_url" type="string" value="file://right_camera_calibration.yaml" />
    </node>
  </group>  
</launch>

The left.yaml and right.yaml files are in the same directory as the launch file, and they looks like this:

image_width: 640
image_height: 480
camera_name: narrow_stereo/left
camera_matrix:
  rows: 3
  cols: 3
  data: [788.542495, 0, 327.486858, 0, 791.888555, 225.27738, 0, 0, 1]
distortion_model: plumb_bob
distortion_coefficients:
  rows: 1
  cols: 5
  data: [0.145671, -0.706881, 0.00285, -0.00085, 0]
rectification_matrix:
  rows: 3
  cols: 3
  data: [0.996588, -0.063317, -0.052951, 0.06356, 0.997974, 0.002905, 0.05266, -0.006261, 0.998593]
projection_matrix:
  rows: 3
  cols: 4
  data: [1224.680474, 0, 566.859081, 0, 0, 1224.680474, 246.882917, 0, 0, 0, 1, 0]

I have the following topics:

/rosout
/rosout_agg
/stereo/left/camera_info
/stereo/left/image_raw
/stereo/left/image_raw/compressed
/stereo/left/image_raw/compressed/parameter_descriptions
/stereo/left/image_raw/compressed/parameter_updates
/stereo/left/image_raw/compressedDepth
/stereo/left/image_raw/compressedDepth/parameter_descriptions
/stereo/left/image_raw/compressedDepth/parameter_updates
/stereo/left/image_raw/theora
/stereo/left/image_raw/theora/parameter_descriptions
/stereo/left/image_raw/theora/parameter_updates
/stereo/right/camera_info
/stereo/right/image_raw
/stereo/right/image_raw/compressed
/stereo/right/image_raw/compressed/parameter_descriptions
/stereo/right/image_raw/compressed/parameter_updates
/stereo/right/image_raw/compressedDepth
/stereo/right/image_raw/compressedDepth/parameter_descriptions
/stereo/right/image_raw/compressedDepth/parameter_updates
/stereo/right/image_raw/theora
/stereo/right/image_raw/theora/parameter_descriptions
/stereo/right/image_raw/theora/parameter_updates

The camera_info streams messages like this:

---
header: 
  seq: 43435
  stamp: 
    secs: 1368651668
    nsecs: 147961861
  frame_id: left
height: 480
width: 640
distortion_model: ''
D: []
K: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
R: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
P ...
(more)
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Closed for the following reason question is not relevant or outdated by tfoote
close date 2017-06-07 20:12:30.893088

Comments

Hello ZoltanS,

I am also looking for how to use these calibration files in the camera. I tried your method, and it makes no change in the output. But however, you are getting all zeros in camera info, that means your camera is un-calibrated (correct me if wrong). But for me I am getting some value

saurabh gravatar imagesaurabh ( 2018-01-11 01:15:40 -0500 )edit

If camera info is all zeros, it means camera is not calibrated. Please have a look on below link: https://answers.ros.org/question/2233...

saurabh gravatar imagesaurabh ( 2018-01-11 01:17:13 -0500 )edit