omni_proc_ros

Omnidirectional camera model processing ROS package via image transport.

Installation

Git clone the repository into your workspace (e.g. catkin_ws).

$ cd catkin_ws/src
$ git clone https://github.com/1487quantum/omni_proc_ros.git

After that, recompile the workspace.

$ catkin_make

Calibration

Note: The calibration executables have to be compiled seperately, and would be available in the build directory after compilation.

Compilation

Update the compile_calib.sh permission & run the script to compile the calibration executable files: omni_calib & omni_calib_stereo.

$ chmod +x compile_calib.sh
$ ./compile_calib.sh

To run the executable:

$ cd build
$ ./omni_calib [Parameters]

More details on the usage is available in Calibration executables section below.

Obtaining the images

The images to be used for the calibration could be obtained via the ROS camera_calibration package. Perform the calibration via cameracalibrator.py, and click "Save" after the calibration is done (after all the gauge are green). A calibrationdata.tar.gz would be saved in the /tmp/ directory. Uncompress the file, extract the images and save it in a new directory.

The calibration info from the camera_calibration would not be used.

Image list

The sample imagelist files are available in the sample_config directory, and ensure that there are at least 20 images used in the calibration.

The image list would be using OpenCV Storage xml format, which follows this template:

<?xml version="1.0"?>
<opencv_storage>
<images>
[Full path of the images]
...
</images>
</opencv_storage>

Mono image list

The imagelist would be the same as above, ensure that the full image path is used instead of relative path.

<?xml version="1.0"?>
<opencv_storage>
<images>
 /home/ubuntu/cam_ws/omni_proc/calibration/sample_config/img/01.png
...
 /home/ubuntu/cam_ws/omni_proc/calibration/sample_config/img/10.png
</images>
</opencv_storage>

The sample file is available as imagelist_mono.xml.

Stereo image list

The imagelist would be similar to the mono image list, ensure that there are 2 seperate image list for both left and right.

The sample file is available as imagelist_stereo_l.xml and imagelist_stereo_r.xml respectively.

Calibration executables

Image status

There would be a status for image when the calibration is running.

• Green tick - The checkerboard is detected and the image is used in the calibration.
• Red Cross - The checkerboard is not detected & hence not used in the calibration.
• ? - The image could not be found in the specified location/path.

omni_calib [Mono]

Performs camera calibration with the provided imagelist file, which uses the xml format. Ensure that the full image path is entered instead of the relative path.

$ ./omni_calib [IMG_LIST]  [CHECKBOARD_HORIZONTAL_POINTS]   [CHECKBOARD_VERTICAL_POINTS]  [SQUARE_WIDTH (mm)]

• IMG_LIST: List of images to be used for calibration. (A sample could be found in the sample directory.)
• CHECKBOARD_HORIZONTAL_POINTS: Number of horizontal points on checker, count by edges of square.
• CHECKBOARD_VERTICAL_POINTS: Number of vertical points on checker, count by edges of square.
• SQUARE_WIDTH: Size of checkerboard square, measured in millimetres (mm).

Note: Ensure that the both checkerboard horizontal & vertical points are more than 2, else the calibration wouldn't work!

At the end of the calibration, the number of images used would be stated below.

omni_calib_stereo

Performs camera calibration with the provided imagelist file, which uses the xml format. Ensure that the full image path is entered instead of the relative path.

$ ./omni_calib_stereo [IMG_LIST_LEFT]  [IMG_LIST_RIGHT]  [CHECKBOARD_HORIZONTAL_POINTS]   [CHECKBOARD_VERTICAL_POINTS]  [SQUARE_WIDTH (mm)]

• IMG_LIST_LEFT: List of left images to be used for calibration. (A sample could be found in the sample directory.)
• IMG_LIST_RIGHT: List of right images to be used for calibration. (A sample could be found in the sample directory.)
• CHECKBOARD_HORIZONTAL_POINTS: Number of horizontal points on checker, count by edges of square.
• CHECKBOARD_VERTICAL_POINTS: Number of vertical points on checker, count by edges of square.
• SQUARE_WIDTH: Size of checkerboard square, measured in millimetres (mm).

Note: Ensure that the both checkerboard horizontal & vertical points are more than 2, else the calibration wouldn't work!

At the end of the calibration, the number of images used would be stated below.

Param

After running the calibration, the calibration output (e.g. out_camera_params.xml) would be generated. Place the file in the param directory and rename it to out_camera_params.xml. This configuration would be used to recitify the input images.

Launch files

Launch the omni_proc_ros node via omni_mono.launch. This would recitfy the incoming image feed using the omnidirectional camera model of OpenCV.

$ roslaunch omni_mono_proc omni_mono.launch