GLOMAP 在 ETH3D 地形上的多摄像头装置: 尽管拼接质量相似,但与 COLMAP 相比,地面真实值旋转精度明显更差

Summary

I am comparing the sparse reconstruction quality of COLMAP and GLOMAP on the ETH3D low-res many-view terrains dataset with a synchronized 4-camera rig setup.

GLOMAP reconstructs the subset successfully and is fast. The sparse reconstruction size and reprojection error are reasonably close to COLMAP. However, the aligned ground-truth rotation error is much worse for GLOMAP, while the position error is relatively close.

I would like to understand whether this is expected for GLOMAP on calibrated multi-camera rig datasets, or whether I may be missing a setting / conversion step related to rig calibration, sensor_from_rig, relative poses, rotation averaging, global positioning, or bundle adjustment.

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Dataset

• Dataset: ETH3D low-res many-view training, sequence terrains
• Images: undistorted PINHOLE
• Rig: 4 synchronized cameras
• Full dataset: 165 frames / 660 images
• Subset used here: 50 evenly sampled synchronized frames / 200 images
• Masks: none
• Rig setup: generated via rig_configurator
• GT evaluation: aligned pose metrics against the ETH3D calibration / ground-truth reference

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Builds used

• COLMAP Ceres reference: local Ceres baseline build
• COLMAP Caspar: local Caspar f32 build, generated/fixed-rig setup
• GLOMAP: local branch glomap-eth3d-relpose-import-fix-20260504-141430, commit 0edb1b8435e0f9a594318908b81a31f078a51bf7
• GLOMAP notes: this local build includes ETH3D relative-pose import fixes and final external Caspar BA support

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Subset results

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Candidate	Total	Mapper	Final BA	Points	Obs	Track	Reproj	GT pos med	GT rot med
COLMAP Ceres fixed rig	83.74s	44.28s	n/a	25,430	302,870	11.910	0.465167 px	0.004239 m	0.441720°
COLMAP Caspar generated/fixed	72.17s	32.71s	n/a	25,421	302,839	11.913	0.464941 px	0.004724 m	0.846938°
GLOMAP 8192 + final Caspar BA	71.52s	31.34s	0.87s	24,436