Camera Calibration in Driveworks 1.2

Hello,

I have some questions about the camera calibration step by step guide in Driveworks 1.2.

First of all, in the guide you say that the Camera Targets must be 1x1m but shouldn’t they be an A0 size as bar length of the targets in some of the pictures you show is 400mm?

Another question, is there any problem if the targets are placed at different heights or distance from the ego car in the calibration scene?

How many constraints should I try to get from the intrinsic calibration tool to consider it as a good calibration?

Kind Regards.

Hi,

1) Camera targets should be larger than 1m.
Please noticed that the “400mm” is the bar length(a straight line in the bottom of the target), rather than the target size.

2) No. The calibration tool will generate a 3D position so it can estimate the height of targets.

3) It’s hard to tell how many constraint will be good.
Just record a video with good quality(sufficient light) and the following movement:
[i]------------------------------------------------------------------------------
Move checkerboard pattern in front of the camera from left to right
While moving rotate the pattern in all dimensions, i.e. pitch, roll and yaw
While moving try to get closer as well as further away from the camera, i.e scale

[/i]
Thanks.

Hello,

I know that 400mm is the bar length. The thing is that in the targets you provide the bar length of an A4 paper is 100mm, 141.4mm for an A3, 200mm for an A2, 282mm for an A1 and finally 400mm for an A0.

That’s why I think and assumed that you are using A0’s in the calibration step by step sample of the documentation.

Regards.

Hi,

Just make sure the size is larger than 1m and the aspect ratio is fixed.
Thanks.