Automated Vitreous Haze Grading Through Frequency-Domain Image Analysis

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Solution Overview

Problem

Existing automated systems for quantifying vitreous haze in fundoscopic images, such as the Passaglia quantitative vitreous haze algorithm (PQVHA), suffer from poor performance when compared to human expert graders, necessitating improved methods for accurate vitreous haze grading.

Innovation Solution

The Robust Quantitative Vitreous Haze Algorithm (RQVHA) involves isolating a color channel, applying normalization and window functions, smoothing, and using a high-pass filter to transform the image into a frequency domain for calculating a clarity score and haziness score, thereby enhancing grading accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If automated grading algorithms like PQVHA are used to quantify vitreous haze, then productivity is improved by automating the grading process, but measurement precision deteriorates due to poor performance compared to human expert graders

Engineering Contradiction:
Improveautomation of grading processVSAvoidgrading accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent transforms the image processing approach by converting from spatial domain to frequency domain analysis. This fundamental parameter change in the analytical method enables the automated algorithm to achieve expert-level grading accuracy while maintaining automation benefits. The frequency domain transformation allows for more robust haze quantification that is less sensitive to image quality variations and artifacts.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional spatial domain image processing methods with frequency domain analysis. This substitution of the processing mechanism enables the system to achieve both automation and expert-level accuracy by utilizing Fourier transformation and spectral analysis instead of conventional spatial filtering and intensity-based methods.

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

2Measurement precision

If traditional image processing methods are used, then device complexity is kept simple, but measurement precision deteriorates due to inability to achieve expert-level accuracy

Engineering Contradiction:
Improvegrading accuracyVSAvoidprocessing algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs frequency domain analysis and Fourier transformation to replace traditional spatial domain processing. This mechanistic substitution achieves expert-level grading accuracy through spectral analysis, while the systematic approach maintains manageable algorithmic complexity through well-established signal processing techniques.

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

3Measurement precision

If standard fundoscopic images are used directly for grading, then ease of operation is maintained by using existing images, but measurement precision deteriorates due to sensitivity to image artifacts and quality variations

Engineering Contradiction:
Improvegrading consistencyVSAvoidimage preprocessing requirement
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent applies frequency domain transformation and spectral analysis as preliminary processing steps that robustly handle image artifacts and quality variations. This preliminary action in the frequency domain prepares the data for accurate haze quantification without requiring extensive manual preprocessing or image selection, maintaining ease of operation while achieving consistent expert-level accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The frequency domain serves as an intermediary representation between the raw spatial domain image and the final haze quantification. This intermediate frequency domain analysis acts as a mediator that filters out artifacts and quality issues present in standard fundoscopic images, enabling precise grading from routinely captured images without additional preprocessing steps.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS20250225656A1Systems and methods for determining vitreous haze
Publication Date: 2025.07.10 REGENERON PHARMACEUTICALS INC
  • US20250225656A1 patent drawing
  • US20250225656A1 patent drawing
  • US20250225656A1 patent drawing

AI summary

An example embodiment of the present disclosure provides systems and methods for grading vitreous haze. A color fundoscopic photograph may be obtained. A color channel of the color fundoscopic photograph may be isolated. The color channel of the color fundoscopic photograph may be normalized. A window function may be applied to the normalized color channel to obtain a windowed color channel. A smoothing function may be applied to the windowed color channel to obtain a smoothed color channel. A high-pass filter may be applied to the smoothed color channel to obtain a filtered color channel. The filtered color channel may be transformed to a frequency domain from a spatial domain. A magnitude spectrum may be calculated. The magnitude spectrum may be integrated to determine a clarity score. A haziness score may be calculated based on the clarity score.