Intrinsic only camera calibration using Checkerboard

Hello,

We are trying to calibrate the cameras using the 10x7 checkerboard provided with the Drive AGX in Driveworks 10.

We are following the steps in the documentation DriveWorks_SDK_Reference/Static_camera_calibration/5.1-Intrinsic-only-Calibration. We successfully created the “intrinsics.json” file in the proposed directory structure.

However, in the 4th step which is “Execute the Graph Calibration Tool as demonstrated in 4.3.2 Extrinsic Calibration Execution.” we are facing problems.

Since we are not using April tags we shouldn’t need “targets.json” file but “./calibration-graph-cli” command asks for that file anyway.

And when we provide the default targets.json file from the DriveWorks software the output of the “./calibration-graph-cli”, which is “calibrated-graph.json” does not have any points as in the documentation.

Thank you for your assistance,

Best

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Dear otmiz1,
you can only use checkerboard for intrinsic calibration and not for extrinsics. if you want to do extrinsics you need april tags

Hello SivaRamaKrishnaNV,

We are using the checkerboard only for the intrinsic calibration as you said. But we are stuck after running the ./camera-intrinsics-constraints. It creates the corresponding .json file but after that we cannot create calibrated-graph.json file using the built in functions.

Thank you

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Hello SivaRamaKrishnaNV,

Can you kindly support us regarding this topic. Our aim is already doing only intrinsic calibration.

Thank you

Hi Otemiz1,

The targets.json file is be required but not used in the case of the checkerboard. This is a limitation with flexibility in the tool.

Can you provide more details as to what you are expecting from the output of “./calibration-graph-cli”? Does it produce the calibrated-graph.json file with some content or is it empty? Does it produce the validation image? What is the output of the cli tool?

I should mention, Step 5 is the one that converts the intermediate step #4 into a readable file. calibrated-graph.json is not a human readable format.

Hello LukeNV,

Previously calibration-graph-cli wasnt generating any validation image but after running it without any input arguments It worked now. I thank you for your support,

Best