Eye Tracking Slippage Compensation Using Glint Reference Points
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Solution Overview
Problem
Two-dimensional video-based eye tracking systems in head-mounted displays face challenges in compensating for slippage due to the weight of the device or user movement, lacking a known solution for maintaining accurate gaze tracking.
Innovation Solution
A method that uses glint reference points derived from infrared light reflections to detect and compensate for slippage, without requiring a three-dimensional model of the eye, by establishing a first set of glint reference points during calibration and monitoring for changes during usage, allowing for accurate gaze tracking even when the head-mounted display shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three-dimensional models of the eye are used for slippage compensation, then slippage compensation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the essential glint reference points from the complex three-dimensional eye model, using merely two points (first and second glint reference points) derived from glint patterns. This extraction approach achieves slippage compensation without requiring the full complexity of 3D eye modeling, thereby maintaining accuracy while reducing system complexity.
Solution Approach 2:
The patent creates a simplified two-dimensional copy of the glint pattern on the display surface, mapping the glint reference points from the eye image coordinates to the display panel coordinates through calibration. This 2D copying approach replicates the essential information needed for slippage detection without requiring three-dimensional reconstruction.
2Device complexity
If calibration mapping is established without slippage compensation, then system simplicity is maintained, but gaze tracking accuracy deteriorates under slippage conditions
Solution Approach 1:
The patent implements a feedback mechanism where the glint reference points are continuously monitored during operation. By comparing the current positions of the glint reference points with their calibrated positions, the system detects slippage and dynamically adjusts the gaze point calculation to compensate for the detected displacement, thereby maintaining accuracy despite head movement or device shifting.
Solution Approach 2:
The patent performs preliminary calibration to establish the mapping between eye image coordinates and display panel coordinates, storing the initial glint reference point positions. This preliminary action creates a reference framework that enables subsequent real-time slippage detection and compensation without requiring recalibration, maintaining both simplicity and accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables effective slippage compensation in two-dimensional video-based eye tracking systems, ensuring accurate gaze tracking and enhancing virtual and augmented reality applications by maintaining precise alignment between the display and the user's gaze.
Implementation Method 1
determining a first set of one or more glint reference points derived from one or more glints that were imaged during a calibration
Data Source
AI summary
Methods for using a head mounted display (HMD) can detect slippage of the HMD through the use of a comparison between, for example, a calibrated glint reference point and a glint reference point calculated during monitoring of glints during usage of the HMD.