Pupillary Distance Measurement Using 2D and 3D Depth Maps

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Solution Overview

Problem

Current methods for measuring pupillary distance (PD) are inaccurate, cumbersome, and resource-intensive, often requiring human intervention and can violate social distancing guidelines, leading to discomfort and inefficiencies in eyewear fitting and e-commerce processes.

Innovation Solution

A system and method using image processing algorithms to localize pupils in 2D images and 3D data, calculating PD with improved accuracy and convenience, allowing for contactless measurements that can be stored for virtual try-on and product recommendations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional PD measurement methods (ruler, corneal reflection pupillometer) are used, then PD measurement can be obtained, but measurement precision and reliability are poor due to human error and calibration issues

Engineering Contradiction:
ImprovePD measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces manual mechanical measurement methods (ruler alignment, corneal reflection pupillometer) with an automated image processing system that uses 2D images and 3D depth maps to calculate PD. This substitution eliminates human error in measurement and calculation, providing consistent and reliable results through algorithmic processing rather than manual intervention.

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

Solution Approach 2:

The patent creates a digital copy of the subject's facial features through image capture and 3D depth mapping. By working with digital representations rather than physical measurements, the system can accurately locate pupils and calculate PD without the errors inherent in physical ruler-based methods, improving both precision and reliability.

Inventive Principle:
Principle #26Copying

2Ease of operation

If corneal reflection pupillometer is used for PD measurement, then PD can be measured, but the method requires close proximity between subject and measurer, violating social distancing guidelines

Engineering Contradiction:
Improvecontactless measurement capabilityVSAvoidsocial distancing violation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent uses digital image copying technology to capture facial features from a distance. By creating and processing digital representations of the subject's face through 2D images and 3D depth maps, the system eliminates the need for close physical contact, enabling contactless PD measurement that complies with social distancing requirements.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical corneal reflection pupillometer with an optical-digital system using cameras and image processing algorithms. This substitution allows measurement to be performed remotely through image capture and computational analysis, eliminating the need for close proximity between measurer and subject.

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

3Productivity

If manual PD measurement with ruler is used, then PD can be obtained, but the method is cumbersome and time-consuming requiring subject positioning and manual alignment

Engineering Contradiction:
Improvemeasurement efficiencyVSAvoidmeasurement convenience
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent enables the measurement system to automatically perform all operations without manual intervention. The image processing algorithms autonomously locate pupils, calculate distances, and generate PD measurements, eliminating the need for operators to manually position rulers or align measurement tools, thereby dramatically improving efficiency and convenience.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement operations with automated computational processes. Image processing algorithms automatically identify facial features and calculate PD, substituting the cumbersome manual ruler-based method with an efficient digital system that requires minimal user input and delivers rapid results.

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

4Adaptability or versatility

If e-commerce customers submit photos for remote PD measurement, then PD can be obtained without store visit, but the method lacks accuracy due to variable photo quality and processing challenges

Engineering Contradiction:
Improvee-commerce integration capabilityVSAvoidremote measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent transitions from 2D photo analysis to 3D depth map processing for PD measurement. By incorporating third-dimensional depth information, the system overcomes the limitations of flat image processing, achieving accurate pupil localization and PD calculation even with photos taken in various e-commerce settings, thereby maintaining precision while enabling remote measurement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces manual photo processing methods with automated image and depth map processing algorithms. These computational methods systematically analyze facial features and calculate PD, eliminating the variability and errors associated with manual processing of e-commerce customer photos while maintaining adaptability to different submission formats.

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

Data Source

PatentUS12108988B2System and method for measuring pupillary distance and uses thereof
Publication Date: 2024.10.08 WARBY PARKER INC
  • US12108988B2 patent drawing
  • US12108988B2 patent drawing
  • US12108988B2 patent drawing

AI summary

A method of operating a pupillary distance system is disclosed. The method comprises the steps of capturing, with at least one camera of the pupillary distance system a 2D image and a corresponding 3D depth map of a face of a subject. A determination of pupil localization information is made using the 2D image and corresponding 3D depth map. The pupil location is further refined based on the pupil localization information. Pupil center coordinates are determined and the pupillary distance is calculated for a subject between centers of each pupil. Processes and uses thereof are also disclosed.