High initial Reprojection Error in Camera-IMU Calibration

[qpoisson]

Hello,

I'm currently encountering an issue while performing camera-IMU calibration where the initial reprojection error is significantly larger than expected.

Before Optimization

Normalized Residuals

Reprojection error (cam0): mean 11.9616155054, median 1.30029876276, std: 56.1815593362
Gyroscope error (imu0): mean 11.9233885755, median 3.08777814209, std: 23.3648720494
Accelerometer error (imu0): mean 43.5661130077, median 39.4930018658, std: 13.5736391727

In contrast, when I use the camera calibration validator in Kalibr, the reprojection error is approximately 0.2, which is markedly lower.

I'm unsure as to why there's such a disparity between these two results. Could there be an issue with the calibration process or the tools I'm using? I'd appreciate any suggestions or guidance on potential solutions or next steps to take to resolve this.