Infrared Reflection Removal for Eye Tracking Accuracy
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Solution Overview
Problem
Camera-based eye tracking technologies face challenges in low illumination environments due to reduced image quality, and infrared cameras struggle with accuracy when reflections occur on glasses, such as those worn by users.
Innovation Solution
A method and apparatus that utilize an infrared light source during an 'on' interval and deactivate it during an 'off' interval to generate input and reference images, respectively, and subtract pixel values to create a difference map, identifying and removing reflection regions to enhance eye tracking accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If infrared camera is used in low illumination environment, then image quality is improved, but eye tracking accuracy deteriorates due to reflection on glasses
Solution Approach 1:
The infrared light source is activated periodically in alternating intervals (first interval on, second interval off) to illuminate the subject. This periodic activation allows the system to capture images with infrared illumination while also capturing reference images without illumination, enabling reflection removal through subtraction while maintaining adequate illumination for image capture in low light conditions.
Solution Approach 2:
The reflection caused by infrared light on glasses, which initially degrades eye tracking accuracy, is converted into a detectable signal. By capturing images with and without infrared illumination and subtracting them, the system identifies reflection regions through the difference map and removes them, thereby eliminating the harmful effect of reflections on measurement precision.
2Illumination intensity
If infrared light source is continuously activated, then image quality in low illumination is improved, but energy consumption increases
Solution Approach 1:
Instead of continuous activation, the infrared light source is activated periodically in alternating intervals. During the first interval, the light source is on to capture images with infrared illumination. During the second interval, the light source is off to capture reference images without illumination. This periodic action maintains adequate illumination for image capture while significantly reducing energy consumption compared to continuous activation.
Solution Approach 2:
The system maintains continuous image capture operation by alternating between two states (with and without infrared illumination) rather than interrupting the capture process. This ensures that useful action (image acquisition for eye tracking) continues without interruption while energy consumption is reduced through periodic illumination.
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 allows for accurate eye tracking in low illumination environments by minimizing the impact of reflections, thereby improving the success rate and accuracy of eye tracking systems, including those used in vehicles and other applications.
Implementation Method 1
an infrared light source (520), and a processor (1320). The image acquirer (510) is configured to acquire an input image of an object, based on activation of the infrared light source (520)
Implementation Method 2
generating the input image, based on a first plurality of rays that is received from the object, during the on interval
Data Source
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AI summary
A method and apparatus for detecting a reflection are provided. The method includes acquiring an input image of an object, based on an activation of an infrared light source, acquiring a reference image of the object, based on a deactivation of the infrared light source, and extracting a reflection region from the input image, based on the input image and the reference image.