Head-Worn Camera Window Calibration for Curved Lens Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Curved window-elements in head-worn devices cause image distortions, affecting the performance of AR/VR functions such as eye-tracking.
Innovation Solution
An online calibration process adjusts window extrinsics based on detected and expected fiducials to reduce distortions, using a fiducial-detection process that is invisible to the user and updates extrinsic parameters during device use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a curved window-element is used in the head-worn device, then the aesthetic appearance and structural integrity are improved, but image distortions occur affecting AR/VR function performance
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting window extrinsic parameters (position, orientation, shape) through online calibration. The system captures images of a fiducial through the curved window, compares detected fiducial position to expected position, and updates extrinsic parameters to compensate for distortions. This transforms the static curved window into a dynamically calibrated optical element that maintains imaging accuracy despite its curved geometry.
2Manufacturing precision
If offline calibration is performed during factory calibration, then initial window extrinsics are established, but the calibration cannot adapt to changes in window shape, orientation, or position during use
Solution Approach 1:
The patent implements dynamics by transitioning from static offline calibration to dynamic online calibration. The system continuously or periodically recalibrates window extrinsics during device operation by detecting fiducial markers through the curved window and adjusting parameters in real-time. This dynamic approach allows the calibration to adapt to changes in window geometry, temperature, or mechanical positioning that occur during actual use.
Solution Approach 2:
The patent applies feedback by using detected fiducial positions as feedback signals to adjust window extrinsic parameters. The system captures images containing a fiducial, compares the detected fiducial location against the expected location based on stored extrinsics, and uses the discrepancy to update the extrinsic parameters. This closed-loop feedback mechanism ensures continuous optimization of calibration accuracy.
3Manufacturing precision
If fiducial detection and online calibration are implemented, then image distortion is reduced improving AR/VR functions, but device complexity increases
Solution Approach 1:
The patent applies self-service by enabling the device to perform its own calibration automatically without external intervention. The system uses an on-device camera to capture fiducial markers, processes images to detect fiducial positions, and autonomously updates window extrinsic parameters. This self-calibrating capability eliminates the need for complex external calibration equipment or manual adjustment procedures.
Data Source
AI summary
A head-worn device may be configured with a curved window-element that can generate distortion in images captured by a camera of the head-worn device. Window extrinsics describing the shape, orientation, and/or position of the curved window-element may be used as a calibration to reduce the distortion. An online calibration process may be run at times during use so that the window extrinsics can be updated to accurately represent the curved window-element after changes in the shape, orientation, and/or position of the curved window-element occur.