Abstract
In order for a binocular head to perform optimal 3D tracking, it should be able to verge its cameras actively, while maintaining geometric calibration. In this work we introduce a calibration update procedure, which allows a robotic head to simultaneously fixate, track, and reconstruct a moving object in real-time. The update method is based on a mapping from motor-based to image-based estimates of the camera orientations, estimated in an offline stage. Following this, a fast online procedure is presented to update the calibration of an active binocular camera pair. The proposed approach is ideal for active vision applications because no image-processing is needed at runtime for the scope of calibrating the system or for maintaining the calibration parameters during camera vergence. We show that this homography-based technique allows an active binocular robot to fixate and track an object, whilst performing 3D reconstruction concurrently in real-time.
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Notes
The \(\bar{\boldsymbol{U}}\) matrix was obtained by computing columns \(\bar{\boldsymbol{u}}\) and \(\bar{\boldsymbol{w}}\) as the leading eigenvectors of \(\sum_{j} \boldsymbol{u}_{j} \boldsymbol{u}_{j}^{\top}\) and \(\sum_{j} \boldsymbol{w}_{j} \boldsymbol{w}_{j}^{\top}\) respectively, with \(\bar{\boldsymbol{v}} = \bar{\boldsymbol{u}}^{*}\).
The statistics were computed after excluding the ‘perfect’ values at θ=0.
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Sapienza, M., Hansard, M. & Horaud, R. Real-time visuomotor update of an active binocular head. Auton Robot 34, 35–45 (2013). https://doi.org/10.1007/s10514-012-9311-2
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DOI: https://doi.org/10.1007/s10514-012-9311-2