Bag format

All applications in Kalibr use ROS bags as a source for its sensor data (image and IMU).

###Can I use image files and IMU data as CSV files? A bagcreater script is provided to use image files and/or IMU data for the calibration

####bagcreater This script allows you to create a ROS bag from raw image files and optionally IMU data. The files have to be organized in folders as illustrated below for a system with two cameras and an IMU

+-- dataset-dir<br>
    +-- cam0<br>
    │   +-- 1385030208726607500.png<br>
    │   +--      ...<br>
    │   \-- 1385030212176607500.png<br>
    +-- cam1<br>
    │   +-- 1385030208726607500.png<br>
    │   +--      ...<br>
    │   \-- 1385030212176607500.png<br>
    \-- imu0.csv<br>

The imu0.csv file is structured as follows (timestamps=[ns], omega=[rad/s], alpha=[m/s^2])

timestamp,omega_x,omega_y,omega_z,alpha_x,alpha_y,alpha_z
1385030208736607488,0.5,-0.2,-0.1,8.1,-1.9,-3.3
...
1386030208736607488,0.5,-0.1,-0.1,8.1,-1.9,-3.3

To create the ROS bag run the following command:

rosrun aslam_calibration bagcreater --folder dataset-dir --output awsome.bag

The data will be written to the following topics:

• /cam0/image_raw
• /cam1/image_raw
• /imu0

####bagextractor The bagextractor exports a ROS bag containing image and/or IMU data to image files and IMU data as csv files.

Example usage:

rosrun aslam_calibration bagextractor --image-topics /cam0/image_raw /cam1/image_raw --imu-topics /imu0 --output-folder dataset-dir --bag awsome.bag