Calibration for one LIDAR and one camera

This code is reffered from the old version of Autoware, and only extract the calibration part.

This code has been tested in the environment of Ubuntu18.04, ROS Melodic. For other versions of ROS, it should also work theoretically.

ROS should be installed firstly. The install tutorial can refer https://www.ros.org/install/.
Code compile

Firstly, new a directory called /catkin_usv in your /home/${YOUR NAME} and add a new directory /src in /home/${YOUR NAME}/catkin_usv . Then extract our repository and put it into /home/${YOUR NAME}/catkin_usv/src.
```
$cd /home/${YOUR NAME}/catkin_usv
$catkin_make
```

Could NOT find jsk_recognition_msgs (missing: jsk_recognition_msgs_DIR)

解决：可能是安装ros包的时候没装完整。

$ sudo apt install ros-melodic-jsk-recognition-msgs

fatal error: nlopt.hpp: No such file or directory

解决：

$ sudo apt-get install libnlopt-dev

Preparation

We should prepare a chessboard which is 8X6 for pattern number and 0.108mX0.108m for pattern size. Other number and size also be alright. But Note: sparser your point cloud is, bigger the chessboard shold be. For 16-lines LIDAR, the pattern size can be about 0.2mX0.2m.
Calibration ROSBAG collection

According to the official document: ./doc/CalibrationToolkit_Manual.pdf, we set 9 poisitons and 3 configurations with different tilt angles of the plane. Then record it.
```
$rosbag record -O my_calibration_dataset ${Your Image Topic} ${Your Pointcloud Topic}
```

Calibrate

Firstly, you should play the ROSBAG file my_calibration_dataset.bag.

$rosbag play --pause -l my_calibration_dataset.bag

Then, run the calibration toolkit.

$cd /home/${YOUR NAME}/catkin_usv
$source devel/setup.bash
$cd devel/lib/calibration_camera_lidar
$./calibration_toolkit

Then, follow the official step.

Translation : ↑, ↓, ←, →, PgUp, PgDn;
Rotation : a, d, w, s, q, e;
Projection mode switch : 1 for perspective projection, 2 for orthogonal projection;
In orthogonal projection mode : - or , for small viewport, + or . for large viewport;
Point size : o for small, p for large;
Line width : k for narrow, l for broad;
Change background color : b for color selection;
Change light color : n for color selection;
Clear screen : Delete.

arijin / lidar-camera-calibration