Iris Capture Image Sensor with Integrated Region of Interest Logic
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Solution Overview
Problem
Current iris recognition systems are expensive and lack integration, relying on external hardware for image capture and illumination synchronization, and are less accurate when using visible light instead of Near Infrared (NIR) imagery.
Innovation Solution
An integrated circuit with an image sensor, buffer, comparator, and logic for locating the iris based on brightest pixel sets, incorporating autofocus and automatic gain control to enhance image quality and segmentation, while using strobed NIR illumination for accurate iris detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If specialized external hardware is used for image capture and illumination synchronization, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent integrates the image sensor, buffer, comparator, and iris location logic into a single integrated circuit. The image sensor captures images, the buffer stores pixel values, the comparator identifies brightest pixels, and the logic determines iris location - all within one chip, eliminating external hardware components while maintaining detection accuracy
Solution Approach 2:
The integrated circuit performs multiple functions: image capture, data storage, brightness comparison, and iris location determination. This multi-functional design replaces what previously required separate specialized hardware components, reducing system complexity while preserving measurement precision
2Device complexity
If visible light is used instead of NIR illumination, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The system uses Near Infrared (NIR) illumination instead of visible light, changing the wavelength parameter of the light source. This parameter change enables accurate iris imaging while the integrated circuit design keeps the overall system complexity manageable through component integration
3Measurement precision
If the entire image is processed and transmitted, then measurement precision is improved, but loss of substance increases
Solution Approach 1:
The system extracts only the iris region from the entire image for processing and transmission. The integrated circuit identifies the iris location using brightest pixel comparison, then extracts and transmits only the relevant iris data, eliminating the need to process and transmit unnecessary background image data
Solution Approach 2:
The patent implements coarse segmentation of the iris region within the integrated circuit. By dividing the image processing task into location identification (using brightest pixels) and iris extraction, the system achieves accurate segmentation while minimizing data transmission requirements
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
The solution provides a cost-effective, highly integrated, and accurate iris recognition system that reduces system size and bandwidth by segmenting only the iris region, improving focus and contrast, and reducing external circuitry, making it suitable for mass-market consumer electronics.
Implementation Method 1
An image sensor to receive at least one image comprising a plurality of pixels from a camera
Implementation Method 2
The use of NIR permits the capture of iris features with very high contrast. NIR strobed illumination freezes the motion of the subject
Implementation Method 3
The high illumination intensities produce very bright specularities on an eye of the subject, which in turn may be used to locate an iris of the subject
Data Source
AI summary
An integrated circuit has an image sensor to receive at least one image comprising a plurality of pixels from a camera comprising a lens, a buffer communicatively connected to the image sensor for storing values associated with the plurality of pixels, and a comparator communicately connected to the buffer to locate and identify the iris of a subject, in which locating and identifying the iris of the subject is based on a location of each pixel in a brightest pixel set. A method for locating and identifying an iris in an image includes capturing at least one image of an illuminated subject, determining a brightness value for each of the plurality of pixels, determining a location corresponding to each pixel in a brightest pixel set, and identifying the iris in the at least one image based on the location of each pixel in the brightest pixel set.