Fundus Image Correction via Lookup Table
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fundus image detection apparatuses suffer from pincushion distortion when capturing images of the curved fundus of the eye, which complicates diagnosis and is often addressed with costly aspherical lenses, making them unsuitable for low-cost handheld devices.
Innovation Solution
A fundus image detection apparatus comprising an image capturing unit with spherical lenses and an image processing unit using a lookup table to correct pincushion distortion, eliminating the need for expensive aspherical lenses by capturing and correcting distortion patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If aspherical lenses are used to correct pincushion distortion, then image quality is improved, but device cost increases significantly
Solution Approach 1:
The patent replaces the mechanical optical correction system (aspherical lenses) with a digital image processing system. The image processing unit captures the distortion pattern using spherical lenses and applies computational algorithms to correct pincushion distortion in the captured fundus images, thereby achieving high-quality images without expensive aspherical lenses.
Solution Approach 2:
The patent creates a digital model of the distortion pattern by capturing it with the spherical lens system. This distortion pattern copy is then used by the image processing unit to generate correction algorithms that can be applied to all subsequent fundus images, eliminating the need for expensive physical aspherical lenses while maintaining image quality.
2Measurement precision
If aspherical lenses are used to correct pincushion distortion, then diagnostic accuracy is improved, but device complexity increases
Solution Approach 1:
The patent substitutes complex aspherical lens assemblies with a simpler spherical lens system combined with digital image processing. The image processing unit captures distortion patterns and applies computational corrections, reducing mechanical complexity while maintaining or improving diagnostic accuracy through software-based distortion correction.
Solution Approach 2:
The patent changes the approach from physical optical parameter modification (aspherical lens geometry) to digital parameter processing. The system captures images with spherical lenses, then uses image processing algorithms to adjust pixel positions and correct distortion, thereby achieving high diagnostic accuracy with simpler optical components.
3Ease of manufacture
If spherical lenses are used instead of aspherical lenses, then device cost is reduced, but pincushion distortion increases
Solution Approach 1:
The patent replaces mechanical distortion correction (aspherical lenses) with a digital correction system. The image processing unit captures the distortion pattern produced by spherical lenses and applies computational algorithms to correct pincushion distortion, thereby achieving low-cost manufacturing without sacrificing image quality.
Solution Approach 2:
The patent creates a digital representation of the distortion pattern generated by spherical lenses. This distortion model is then used by the image processing unit to generate correction maps that compensate for pincushion distortion in all captured fundus images, enabling the use of inexpensive spherical lenses while maintaining image quality.
Data Source
AI summary
A fundus image detection apparatus capable of detecting a fundus image of an eye of an animal is provided. The fundus image detection apparatus includes an image capturing unit and an image processing unit electrically connected with the image capturing unit. The image processing unit has a lookup table. The image processing unit corrects the fundus image of the eye of the animal according to the lookup table to diminish pincushion distortion. Moreover, a method for obtaining a fundus image of an eye of an animal is also provided.