Geometric calibration for mobile, stereo, autofocus cameras

Mobile, stereo, autofocus cameras present unique challenges for robust and efficient depth estimation. Specifically, existing approaches for calibration of the stereo camera intrinsic and extrinsic parameters are inadequate because of per-shot changes in the configuration, long-term mechanical drift, extremely constrained manufacturing processes, and the requirement for real-world robustness. We present a hybrid strategy that combines a single-photo of a calibration grid in an offline step with online blind refinement, which satisfies all of these goals.