Ophthalmic Parameter Determination Using 3D Frame Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining optical parameters for ophthalmic devices, such as glasses, are prone to measurement errors due to poor positioning and are invasive, requiring manual intervention and specific target frames, which limits precision and applicability.
Innovation Solution
An automatic method using image acquisition systems with stereoscopic or depth cameras to detect characteristic points on the user's face and align a three-dimensional representation of the frame, allowing for precise determination of optical parameters like interpupillary distance and pantoscopic angle without the need for manual intervention or specific markers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If indirect measurement methods using targets are used, then optical parameters can be determined, but measurement errors occur due to poor positioning and parallax
Solution Approach 1:
The patent replaces the mechanical target-based measurement system with a digital image processing system. Instead of using physical targets and manual measurements, the system captures images of the frame worn by the user and automatically extracts optical parameters through image analysis, eliminating positioning errors and parallax effects
Solution Approach 2:
The patent creates a digital copy (image) of the frame as worn by the user and analyzes this copy to determine optical parameters. This allows measurement without physical contact or special positioning, as the image captures the actual wearing conditions including any natural deviations from perfect alignment
2Measurement precision
If target-based measurement systems are used, then optical parameters can be calculated, but the process becomes invasive and requires manual intervention
Solution Approach 1:
The system performs self-service by automatically capturing images and extracting optical parameters without requiring manual intervention. The image processing algorithm automatically identifies frame features, calculates measurements, and determines optical parameters, eliminating the need for operators to position targets or perform manual measurements
Solution Approach 2:
The patent extracts the essential measurement function from the complex target-based system. Instead of requiring physical targets and manual procedures, the system extracts optical parameters directly from regular images of the worn frame, simplifying the overall measurement process while maintaining accuracy
3Productivity
If 2D images are used for measurement, then parameters can be obtained, but inaccuracies occur due to projection of three-dimensional objects
Solution Approach 1:
The patent addresses the 3D to 2D projection problem by using multiple 2D images (stereoscopic or sequential images at different positions) to reconstruct 3D information. This allows accurate determination of optical parameters from the 3D geometry of the worn frame while maintaining the efficiency of 2D image capture and processing
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for automatically determining at least one parameter associated with an ophthalmic device selected by an individual, said device comprising a frame referred to as selected frame, said determination being carried out from an acquired image of the face of the individual wearing the selected frame or a frame of a second ophthalmic device. The method comprises steps of: - detecting at least one characteristic point of at least one eye of the individual the acquired image and estimating the three-dimensional position of the one or more characteristic point(s) detected; - detecting the frame worn and estimating the three-dimensional position of the frame worn by aligning a three-dimensional representation of the frame worn with the frame worn in the acquired image; and - determining the one or more parameters from the relative position of the eyes with respect to the three-dimensional representation of the selected frame.