Real-Time Eyewear Scaling with Facial Landmarks and Depth Maps

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Solution Overview

Problem

Existing augmented reality systems require calibration using reference objects to determine the scale of a user's face, which is burdensome and inefficient, affecting user experience and resource utilization.

Innovation Solution

The system computes a real-world scale of a user's face by combining facial landmarks with a depth map, allowing augmented reality elements to be accurately positioned and sized without calibration, and continuously updates this scale as the user moves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If calibration using reference objects is used to determine face scale, then measurement precision is improved, but device complexity and ease of operation worsen due to burden on user

Engineering Contradiction:
Improveface scale measurement precisionVSAvoiduser operation ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system automatically detects facial landmarks and computes face scale without requiring user action to place reference objects. The computer vision system performs self-service by identifying facial features (eyes, nose, mouth, jawline) and calculating scale parameters autonomously, eliminating the calibration burden from the user while maintaining measurement precision

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical calibration process (physically placing reference objects on the face) with a computational approach using computer vision and machine learning. The system uses algorithms to detect facial landmarks and compute scale through image processing, substituting physical mechanical calibration with digital computational methods

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

2Measurement precision

If calibration using reference objects is used to determine face scale, then measurement precision is improved, but loss of time increases due to calibration requirement

Engineering Contradiction:
Improveface scale measurement precisionVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary action by pre-training machine learning models on large datasets of facial images to recognize facial landmarks and compute scale parameters. This preliminary training enables the system to quickly determine face scale during actual use without requiring time-consuming calibration procedures, as the computational models are already prepared to identify facial features and calculate measurements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the time-consuming mechanical calibration process with rapid computational methods. Computer vision algorithms process facial images in real-time or near-real-time to determine scale parameters, eliminating the need for users to spend time physically calibrating the system with reference objects while maintaining measurement accuracy

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

3Measurement precision

If calibration using reference objects is used to determine face scale, then measurement precision is improved, but use of energy increases due to additional processing

Engineering Contradiction:
Improveface scale measurement precisionVSAvoidsystem energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces the energy-intensive mechanical calibration process with more efficient computational methods. Instead of requiring users to physically position reference objects and the system to process multiple calibration images, the machine learning models directly compute face scale from standard facial images, reducing the number of processing steps and associated energy consumption while maintaining measurement precision

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

Solution Approach 2:

The system performs self-service by automatically detecting facial landmarks and computing scale parameters without requiring additional calibration resources. The computer vision system efficiently processes standard facial images to determine measurements, eliminating the need for separate calibration procedures that would consume additional energy, while maintaining accurate face scale determination

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS12387447B2True size eyewear in real time
Publication Date: 2025.08.12 SNAP INC
  • US12387447B2 patent drawing
  • US12387447B2 patent drawing
  • US12387447B2 patent drawing

AI summary

Methods and systems are disclosed for performing operations comprising: receiving an image that includes a depiction of a face of a user; generating a plurality of landmarks of the face based on the received image; removing a set of interfering landmarks from the plurality of landmarks resulting in a remaining set of landmarks of the plurality of landmarks; obtaining a depth map for the face of the user; and computing a real-world scale of the face of the user based on the depth map and the remaining set of landmarks.