Real-Time Eyewear Sizing Using Face Depth and Landmarks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing augmented reality systems require calibration to determine the scale of a user's face, which is burdensome and inefficient, taking away from the user experience and consuming additional resources.

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 without calibration, and continuously updates this scale as the user moves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional image processing techniques are used to capture and process images of objects, then image processing capability is provided, but the processed images do not represent the true size of the object and require manual measurement tools

Engineering Contradiction:
Improvetrue size measurement accuracyVSAvoidmanual measurement requirement
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system automatically calculates real-world dimensions by integrating camera intrinsic parameters, extrinsic parameters, and image processing algorithms. The processor autonomously determines object size without requiring manual measurement tools or user intervention, making the system self-sufficient for measurement tasks.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement tools (rulers, calipers) with an optical-mechanical system comprising a camera, processor, and algorithm. The system uses camera parameters and image analysis to compute real-world dimensions, substituting physical measurement tools with a digital processing system.

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

2Measurement precision

If a camera is used to capture images for size measurement, then image capture capability is provided, but the images require post-processing to determine true object dimensions

Engineering Contradiction:
Improvereal-world dimension accuracyVSAvoidpost-processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary calibration to determine camera intrinsic parameters (focal length, principal point, distortion coefficients) and stores them for future use. By pre-processing and storing calibration data, the system eliminates the need for time-consuming post-processing calibration steps when measuring objects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from known object dimensions (when available) to refine measurement calculations. The processor compares measured dimensions with reference dimensions and adjusts calculations accordingly, improving accuracy while reducing the need for iterative post-processing.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If manual measurement tools are used alongside image processing, then measurement capability is provided, but the complexity of the system increases

Engineering Contradiction:
Improvedimension measurement accuracyVSAvoidsystem component count
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The camera system is designed to perform multiple functions: capturing images for visual analysis, calculating real-world dimensions, and providing measurement data. By making the camera system universal, the patent eliminates the need for separate manual measurement tools, reducing overall system complexity while maintaining measurement accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the measurement function with the image capture function. The same camera and processor used for image analysis are also used for dimension measurement, combining what were previously separate functions into a unified system, thereby reducing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4315281B1True size eyewear in real time
Publication Date: 2026.05.13 SNAP INC
  • EP4315281B1 patent drawingFigure 1
  • EP4315281B1 patent drawingFigure 2
  • EP4315281B1 patent drawingFigure 3

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.