An error accured when try to calibrate kitti bag.

[Huleyun]

If the issue is about calibration procedure and results:

• [X] I have read data collection instructions
• [X] I have confirmed the program works on example data

Describe the bug This work is quite wonderful which makes me want to validate in kitti dataset. However, an error accured when I run the prepropress command.

To Reproduce Steps to reproduce the behavior:

1. download kitti dataset: https://drive.google.com/drive/folders/1uFpFjxIBtGPnJbl5NnbUPtcEyx-cpufU?usp=drive_link I have use [kitti2bag]() to transform the kitti data into a rosbag.
2. then manually calibrate the bag this is the command I used: ''' rosrun direct_visual_lidar_calibration preprocess kitti_bag kitti_bag_preprocessed \ --image_topic /kitti/camera_color_left/image_raw \ --points_topic /kitti/velo/pointcloud \ --camera_model plumb_bob \ --camera_intrinsics 767.5834,768.4421,200.9368,130.4244 \ --camera_distortion_coeffs -0.0059,-2.4245e-04,-0.4068,0.5534,-8.4002

'''

3. another problem, if I want to calibrate based on a pair of lidar point cloud and image, what should I do. I found that this code need to record at least 2 frames of lidar and camera message for calibrate.

[koide3]

Possibly points msgs in your bag do not have intensity channels as the error on the console states. Can you check if fields in your point msgs contain a field named intensity?

[Huleyun]

Oh, thanks. I just realized that the MI could not calculate if the intensity channel lost. What should I do to only obtain the initial parameters without intensity channel?

[koide3]

Possibly you can feed dummy intensity data and use the manual initial guess UI to align the image with the point cloud by hand.