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Camera Calibration Extrinsics: Recover Scale

asked 2018-01-13 05:45:36 -0500

Geoeo gravatar image


I am trying to perform a calibration procedure on my usb camera. For this I am basing my solution on the open cv c++ samples using a checker board pattern:

I seem to get good enough intrinsics and my rms is around 0.1 However my translation values have a huge range: For example in Z I get values from -1.92353e-26, to 5.04921e+24

For the size of my checkerboard square I use mm, i.e. 29. Thus I expected for the translation vector to be in mm, however the values are not plausible. The picture I take are maximally 1 meter distance from the calibration pattern, so I expected to get values maybe in the range of e+3.

Is there a step I am missing to reconstruct the extrinsics up to scale?

Best, Marc

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answered 2018-01-16 11:03:15 -0500

Geoeo gravatar image

Hey, I fixed the problem. I was accessing the values form my tvec and rvec as floats, when in fact they are doubles! I now get values in the range of 300 to 1000 which makes sense for my calibration environment.

Best, Marc

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Asked: 2018-01-13 05:45:36 -0500

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Last updated: Jan 16 '18