Eye Gaze Tracking Using Neural Network and Kalman Filter

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Solution Overview

Problem

Existing eye gaze tracking methods suffer from limited accuracy in real-world conditions, particularly without dedicated hardware and under varying eye appearance, illumination, head pose, and image quality, which restricts their usability and practicality in mainstream computing devices.

Innovation Solution

A computer-implemented method using an artificial neural network to construct a gaze vector from selected regions of interest, combined with a Kalman filter for precise point of gaze location on a screen, enhancing accuracy without relying on expensive hardware or user-dependent calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If dedicated hardware components (IR cameras, wearable hardware) are used for eye gaze tracking, then measurement precision is improved (accuracy of 0.5°), but device complexity and cost increase

Engineering Contradiction:
Improvegaze tracking accuracyVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces dedicated hardware components (IR cameras, wearable devices) with a standard camera and software-based processing. The system uses a regular camera combined with an artificial neural network to detect eye landmarks and estimate gaze direction, eliminating the need for specialized mechanical or optical hardware while achieving competitive accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a software model (neural network) that learns to replicate the functionality of expensive hardware-based gaze tracking systems. By training the neural network on datasets from various eye tracking devices, the system copies the measurement capabilities of dedicated hardware using only standard camera inputs and computational algorithms

Inventive Principle:
Principle #26Copying

2Measurement precision

If user-dependent calibration procedures are implemented, then measurement precision is improved, but loss of time increases (calibration is time consuming)

Engineering Contradiction:
Improvegaze tracking accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic calibration without requiring user participation or time investment. The neural network is pre-trained on diverse datasets and automatically adapts to individual users through the calibration-free processing pipeline, eliminating the need for manual calibration procedures while maintaining accurate gaze estimation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration data and model parameters are prepared in advance during the offline training phase. The neural network is pre-trained on extensive datasets containing various eye appearances, illuminations, and head poses, so that when the system is deployed, no additional calibration time is required from the user

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If standard cameras are used instead of dedicated hardware, then device complexity is reduced, but measurement precision deteriorates under varying conditions (eye appearance, illumination, head pose, image quality)

Engineering Contradiction:
Improvehardware simplicityVSAvoidgaze tracking accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The neural network is trained to be invariant to changes in various parameters including illumination conditions, head pose angles, eye appearance variations, and image quality levels. By learning from diverse training data spanning these parameter variations, the system maintains stable and accurate gaze estimation across different operating conditions using only a standard camera

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses a universal neural network model that can handle multiple variations in input conditions (different illuminations, poses, eye appearances) through a single unified processing pipeline. This multi-functional approach allows the same hardware and software to perform accurate gaze tracking across diverse scenarios without requiring specialized components

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3893090B1Method for eye gaze tracking
Publication Date: 2022.06.01 IRISBOND CROWDBONDING SL
  • EP3893090B1 patent drawingFigure 1
  • EP3893090B1 patent drawingFigure 2
  • EP3893090B1 patent drawingFigure 3a~3b

AI summary

The invention refers to a computer-implemented method for locating a point of gaze onto a screen (151). The method comprises the step (210) of initiating the acquiring of an image (300) and the steps (220, 230) of initiating the locating of a first face landmark location (301) and a second face landmark location (302) in the image (300). The method further comprises the step (240) of initiating the selecting of a region of interest (310) in the image (300), said selection being performed by using the aforementioned landmark locations (301,302). The method comprises the step (250) of initiating the constructing of a gaze vector, wherein the construction of the gaze vector is performed by means of an artificial neural network using the first region of interest (310) as input. Moreover, the method comprises the step (260) of initiating the locating the point of gaze onto the screen (151), wherein the locating of the point of gaze is performed by means of the gaze vector.