Yaml formats - bygreencn/kalibr GitHub Wiki

Camera-system calibration (camchain.yaml)

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]

IMU configuration (imu.yaml)

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)

Calibration target configuration (target.yaml)

Please refer to the Calibration targets page.