Gaze Tracking Using Virtual Corneal Reflection Vector
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Solution Overview
Problem
Existing gaze tracking devices face challenges in tracking user gaze when the corneal reflection light is obscured due to eyeball motion, leading to impossibility of gaze tracking.
Innovation Solution
A gaze tracking device and method that generate a pupil center virtual reflection (PCVR) vector using a virtual corneal reflection light, allowing gaze tracking even when the actual corneal reflection light is not detected, by maintaining the virtual corneal reflection light at a consistent position and excluding the position of the actual corneal reflection light in image processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the device uses actual corneal reflection light for gaze tracking, then the gaze tracking is accurate when the corneal reflection light is visible, but the gaze tracking becomes impossible when the corneal reflection light disappears due to eyeball rotation
Solution Approach 1:
The patent creates a virtual corneal reflection light that replicates the optical properties and position characteristics of the actual corneal reflection light. This virtual light is generated through image processing algorithms that calculate where the corneal reflection should appear based on the eyeball image and camera geometry, allowing gaze tracking to continue even when the actual reflection is not visible
Solution Approach 2:
The system performs preliminary calculations to determine the expected position of the corneal reflection light based on the eyeball image before attempting to detect it. By pre-computing the virtual corneal reflection light position using the camera's optical axis and the eyeball's apparent position, the system prepares a fallback solution in advance that can be immediately applied when the actual reflection disappears
2Ease of operation
If the device installs camera and light near the eyeball for wearable gaze tracking, then user convenience is improved, but the corneal reflection light disappears depending on eyeball motion
Solution Approach 1:
The patent generates a virtual corneal reflection light that mimics the behavior and position of the actual corneal reflection light. This virtual replica is calculated based on the geometric relationship between the camera, light source, and eyeball, allowing the system to maintain gaze tracking functionality even when the physical corneal reflection becomes invisible due to the close mounting configuration
Solution Approach 2:
The virtual corneal reflection light acts as an intermediary between the actual physical light and the gaze tracking algorithm. Instead of directly detecting the physical corneal reflection which may disappear, the system uses this virtual intermediary representation that can be continuously computed and maintained even when the physical phenomenon is not observable
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
Enables accurate gaze tracking in situations where the actual corneal reflection light is absent, such as when the user is wearing glasses or the device is in motion, by predicting the gazing point based on the PCVR vector and mapping function.
Implementation Method 1
A wearable gaze tracker is a gaze tracking device that improves user convenience by being attached to the body like smart glasses with an embedded display device or a head mounted display (HMD). A gaze tracker may obtain a user's image by using light with a predetermined wavelength and a camera
Data Source
AI summary
Disclosed herein a device tracking gaze and method therefor. The device includes: an image acquisition unit configured to obtain an eyeball image; a pupil detection unit configured to detect a center of pupil by using the eyeball image; a virtual corneal reflection light position generator configured to process the eyeball image so that a virtual corneal reflection light is located at a predetermined point in the eyeball image; and a PCVR vector generator configured to generate a pupil center virtual reflection vector (PCVR vector) based on a position of the pupil center and a position of the virtual corneal reflection light.