No corners could be extracted

[m-rahman13]

Hello,
I use kalibr_calibrate_imu_camera to calibrate the infra1 and imu of realsense d435i, but an OverflowError occurs.

The command is below:
`
rosrun kalibr kalibr_calibrate_cameras --target april.yaml --models pinhole-radtan pinhole-radtan pinhole-radtan --topics /camera/infra1/image_rect_raw /camera/infra2/image_rect_raw /camera/color/image_raw --bag d435cam_color.bag --bag-freq 10.0 --show-extraction

The error:
`importing libraries
Initializing cam0:
Camera model: pinhole-equi
Dataset: d435cam_color.bag
Topic: /camera/infra1/image_rect_raw
[ WARN] [1760079551.443555]: BagImageDatasetReader: truncated 430 / 1762 images (frequency)
Number of images: 1332

(Aprilgrid: Tag detection:4084): dbind-WARNING **: 15:59:11.447: Couldn't connect to accessibility bus: Failed to connect to socket /run/user/1000/at-spi/bus: No such file or directory
Extracting calibration target corners
Progress 1332 / 1332 Time remaining: 59m 59s
[FATAL] [1760079637.691188]: No corners could be extracted for camera /camera/infra1/image_rect_raw! Check the calibration target configuration and dataset.
Traceback (most recent call last):
File "/root/kalibr_workspace/devel/lib/kalibr/kalibr_calibrate_cameras", line 15, in
exec(compile(fh.read(), python_script, 'exec'), context)
File "/root/kalibr_workspace/src/kalibr/aslam_offline_calibration/kalibr/python/kalibr_calibrate_cameras", line 465, in
main()
File "/root/kalibr_workspace/src/kalibr/aslam_offline_calibration/kalibr/python/kalibr_calibrate_cameras", line 188, in main
if not cam.initGeometryFromObservations(observations):
File "/root/kalibr_workspace/src/kalibr/aslam_offline_calibration/kalibr/python/kalibr_camera_calibration/CameraCalibrator.py", line 57, in initGeometryFromObservations
success = self.geometry.initializeIntrinsics(observations)
RuntimeError: [Exception] /root/kalibr_workspace/src/kalibr/aslam_cv/aslam_cameras/include/aslam/cameras/implementation/PinholeProjection.hpp:716: initializeIntrinsics() assert(observations.size() != 0) failed: Need min. one observation
`

ROS Bag Info:
path: d435cam_color.bag
version: 2.0
duration: 58.7s
start: Oct 10 2025 15:19:06.24 (1760077146.24)
end: Oct 10 2025 15:20:04.98 (1760077204.98)
size: 2.5 GB
messages: 5286
compression: none [2047/2047 chunks]
types: sensor_msgs/Image [060021388200f6f0f447d0fcd9c64743]
topics: /camera/color/image_raw 1762 msgs : sensor_msgs/Image
/camera/infra1/image_rect_raw 1762 msgs : sensor_msgs/Image
/camera/infra2/image_rect_raw 1762 msgs : sensor_msgs/Image

I am using a printed April_6x6_80x80cm_A0.pdf. What should I do to fix this?