yaml formats - bygreencn/kalibr GitHub Wiki
This file stores the calibration of the camera intrinsic and extrinsic parameters as well as the spatial and temporal calibration parameters of the IMU with respect to the cameras.
Each camera has the following parameters:
-
camera_model
camera projection type (pinhole / omni) -
intrinsics
vector containing the intrinsic parameters for the given projection type. elements are as follows:
pinhole: [fu fv pu pv]
omni: [xi fu fv pu pv]
ds: [xi alpha fu fv pu pv]
eucm: [alpha beta fu fv pu pv]
see Supported models for more information
-
distortion_model
lens distortion type (radtan / equidistant)
-
distortion_coeffs
parameter vector for the distortion model
see Supported models for more information
-
T_cn_cnm1
camera extrinsic transformation, always with respect to the last camera in the chain
(e.g. cam1: T_cn_cnm1 = T_c1_c0, takes cam0 to cam1 coordinates)
-
T_cam_imu
IMU extrinsics: transformation from IMU to camera coordinates (T_c_i)
-
timeshift_cam_imu
timeshift between camera and IMU timestamps in seconds (t_imu = t_cam + shift)
-
rostopic
topic of the camera's image stream -
resolution
camera resolution [width,height]
Example chain.yaml
cam0:
camera_model: pinhole
intrinsics: [461.629, 460.152, 362.680, 246.049]
distortion_model: radtan
distortion_coeffs: [-0.27695497, 0.06712482, 0.00087538, 0.00011556]
T_cam_imu:
- [0.01779318, 0.99967549,-0.01822936, 0.07008565]
- [-0.9998017, 0.01795239, 0.00860714,-0.01771023]
- [0.00893160, 0.01807260, 0.99979678, 0.00399246]
- [0.0, 0.0, 0.0, 1.0]
timeshift_cam_imu: -8.121e-05
rostopic: /cam0/image_raw
resolution: [752, 480]
cam1:
camera_model: omni
intrinsics: [0.80065662, 833.006, 830.345, 373.850, 253.749]
distortion_model: radtan
distortion_coeffs: [-0.33518750, 0.13211436, 0.00055967, 0.00057686]
T_cn_cnm1:
- [ 0.99998854, 0.00216014, 0.00427195,-0.11003785]
- [-0.00221074, 0.99992702, 0.01187697, 0.00045792]
- [-0.00424598,-0.01188627, 0.99992034,-0.00064487]
- [0.0, 0.0, 0.0, 1.0]
T_cam_imu:
- [ 0.01567142, 0.99978002,-0.01393948,-0.03997419]
- [-0.99966203, 0.01595569, 0.02052137,-0.01735854]
- [ 0.02073927, 0.01361317, 0.99969223, 0.00326019]
- [0.0, 0.0, 0.0, 1.0]
timeshift_cam_imu: -8.681e-05
rostopic: /cam1/image_raw
resolution: [752, 480]
IMUs are configured using a YAML file. Please refer to the example below for details:
imu.yaml
#Accelerometers
accelerometer_noise_density: 1.86e-03 #Noise density (continuous-time)
accelerometer_random_walk: 4.33e-04 #Bias random walk
#Gyroscopes
gyroscope_noise_density: 1.87e-04 #Noise density (continuous-time)
gyroscope_random_walk: 2.66e-05 #Bias random walk
rostopic: /imu0 #the IMU ROS topic
update_rate: 200.0 #Hz (for discretization of the values above)
Please refer to the Calibration targets page.