Cameras are not connected through mutual observations

[ns15417]

when running kalibr_calibrate_cameras i encountered a problem which is listed below: `timestamp cam0 cam1 1575683268.01 84 - 1575683268.06 - 56 1575683268.27 108 - 1575683268.32 - 71 1575683268.81 - 72 1575683269.02 52 - 1575683269.07 - 71 1575683269.26 103 - 1575683269.32 - 123 1575683269.51 108 - 1575683269.56 - 101 1575683269.77 124 -

Cameras are not connected through mutual observations, please check the dataset. Maybe adjust the approx. sync. tolerance. Traceback (most recent call last): File "/home/shinan/Project/kalibr_workspace/devel/bin/kalibr_calibrate_cameras", line 15, in exec(compile(fh.read(), python_script, 'exec'), context) File "/home/shinan/Project/kalibr_workspace/src/kalibr-master/aslam_offline_calibration/kalibr/python/kalibr_calibrate_cameras", line 447, in main() File "/home/shinan/Project/kalibr_workspace/src/kalibr-master/aslam_offline_calibration/kalibr/python/kalibr_calibrate_cameras", line 204, in main graph.plotGraph() File "/home/shinan/Project/kalibr_workspace/src/kalibr-master/aslam_offline_calibration/kalibr/python/kalibr_camera_calibration/MulticamGraph.py", line 308, in plotGraph edge_label=self.G.es["weight"], KeyError: 'Attribute does not exist' ` above is part of the log, I am not sure what is the exact reason of this bug, but according to the bold log, it is said that the cameras are not synchronous. i guess the reason must be that i set my camera frame rate to 4HZ which leads to the two cameras cannot get images at the same time. I think the timestamp also tells the same thing.

I solved this by changing the frame rate of both cameras to 20HZ. Just list this here, if anyone have other explanation please tell me.

[kannidekan]

execuse me, do you know how could i get the IMU YAML file of the requirements in the camera-imu calibration? #341

Thanks very much!

[AbnerCSZ]

Comment this code on line 201 of src/Kalibr/aslam_offline_calibration/kalibr/python/kalibr_calibrate_cameras to solve your problem:

    if not graph.isGraphConnected():
        obsdb.printTable()
        print "Cameras are not connected through mutual observations, please check the dataset. Maybe adjust the approx. sync. tolerance."
        graph.plotGraph()
        sys.exit(-1)

[huonggiangdhtn]

@ns15417 thank you, I had the same propblem, and I changed to 20Hz, it is ok. But I got error at plotGraph

[goldbattle]

Please try PR https://github.com/ethz-asl/kalibr/pull/515 to see if you still get this issue. If so, please provide a bag file this fails on.