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hengli / camodocal

CamOdoCal: Automatic Intrinsic and Extrinsic Calibration of a Rig with Multiple Generic Cameras and Odometry
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Calibrate the extrinsic parameters of a camera rigs with 8 fisheys lens. #85

Open Shine-yzhao opened 5 years ago

Shine-yzhao commented 5 years ago

I don't have GPS, IMU or wheel encoder in my system. How to calibrate the extrinsic parameters of camera rigs with 8 fisheye lenses, and there is the large overlap between adjacent cameras. Could someone give a hint or some samples? Thanks a lot!

Shine-yzhao commented 5 years ago

Seems that I do not have odometry data?

whplh commented 5 years ago

Stereocalibrate any two of them =) Can you provide more information on the camera(s) you are using FOV, sensor/pixel size, diameter of the rig, ..? I guess your goto solution would be one of: https://github.com/ethz-asl/kalibr/wiki/multiple-camera-calibration https://docs.opencv.org/4.0.0-beta/d2/d1c/tutorial_multi_camera_main.html https://sites.google.com/site/prclibo/toolbox The 2nd and 3rd link are related projects. I recommend the first one if you know how to use ROS.

Shine-yzhao commented 5 years ago

Stereocalibrate any two of them =) Can you provide more information on the camera(s) you are using FOV, sensor/pixel size, diameter of the rig, ..? I guess your goto solution would be one of: https://github.com/ethz-asl/kalibr/wiki/multiple-camera-calibration https://docs.opencv.org/4.0.0-beta/d2/d1c/tutorial_multi_camera_main.html https://sites.google.com/site/prclibo/toolbox The 2nd and 3rd link are related projects. I recommend the first one if you know how to use ROS.

@whplh Thanks for your reply! If I stereo calibrates the middle camera with neighbor two cameras, the intrinsic parameters of the middle camera might come to be different in two times. So I have tried the method of the 3rd link. But not successful. It always outputs the error message like this:

Camera #1: Adding photo #18... ....Matches: 180 ....Matches after Homog. Check: 9 ....Invalid photo due to too few inliers by Fundam./Homog. Matrix check: 8 The calibration image I used ( Synchronized adjacent two frames ): image image

For my system，the FOV of every lens is about 220° ，the resolution is 3840*2160 pixels, and the diameter of the rig is about 10cm.

whplh commented 5 years ago

Nice setup =). This is not the place to discuss this stuff. We can talk a little bit in a private thread if you like. But for this setup you should probably use the 1st link. If you stereocalibrate any two of them you want to make sure the intrinsics are not updated during the optimization procedure. Also your calibration results will depend on the camera model you are going to pick. Obviously choosing the pinhole model for such a camera is a bad idea ;) And mei's model is a bit tricky. I don't recommend to use it except you know what you are doing.