Face Model Construction for Ophthalmic Measurement Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for taking measurements for ophthalmic glasses rely on a clip, which is non-deformable and calibrated but difficult to dispense with due to the variability and deformability of human faces.
Innovation Solution
A method involving the location, adjustment, and construction of a face model using multiple acquisition devices to determine characteristic points, adjust them to a reference model, and construct a stable metrological reference model that accounts for facial deformations, allowing the face to serve as a reference without a clip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a clip is used as a reference for measuring facial dimensions, then measurement precision and reliability are improved, but device complexity and ease of operation deteriorate due to the additional hardware requirement
Solution Approach 1:
The invention extracts the reference function from the physical clip and relocates it to the face model itself. The face model contains embedded reference elements that serve as measurement references, eliminating the need for external clip hardware while maintaining measurement precision through the standardized reference points embedded in the digital model.
Solution Approach 2:
The invention creates a digital copy of the face (face model) that includes embedded reference elements. This digital copy serves as the measurement reference instead of requiring a physical clip, allowing measurements to be taken directly against the standardized reference points in the digital model.
2Measurement precision
If a clip is used as a reference for measuring facial dimensions, then measurement precision is improved, but ease of operation deteriorates due to the difficulty of dispensing with the clip
Solution Approach 1:
The reference function is extracted from the physical clip and embedded within the face model itself. This allows the measurement system to operate without requiring the user to handle or position a separate clip device, improving ease of operation while maintaining precision through the embedded reference points.
3Ease of operation
If the face itself is used as a reference without a clip, then ease of operation is improved, but measurement precision deteriorates due to facial deformations and variability
Solution Approach 1:
The invention creates multiple particular models of the face at different instants to capture facial deformations and movements. By dynamically adapting to facial changes through multiple snapshots and selecting or averaging appropriate models, the system maintains measurement precision despite the face being deformable and variable.
Solution Approach 2:
A standardized face model with embedded reference elements is created as a digital copy. This model serves as a consistent measurement reference that is not affected by actual facial deformations, allowing precise measurements to be taken against the standardized reference points in the digital model rather than the variable physical face.
4Measurement precision
If multiple particular models of the face are created to account for deformations, then measurement precision is improved, but device complexity deteriorates due to the complexity of the model construction process
Solution Approach 1:
The system dynamically creates multiple particular models at different acquisition instants to capture facial deformations. This dynamic approach allows the system to adapt to facial changes and select or average appropriate models, improving measurement precision while the automation of the process manages the complexity.
Data Source
Figure 1~3
Figure 2
AI summary
The invention relates to a method for constructing a model of the face of a person which comprises the following steps: locating (L), by means of an acquisition apparatus and at each time of a plurality of acquisition times, a single plurality of characteristic points of said face of the person such as to form a corresponding plurality of specific models of said face of the person each including the positions of said characteristic points of the face of the person at the time associated with the specific model in question; adjusting (A) by determining, for each specific model of said face of the person, a model adjusted relative to a reference model of said face of the person, the adjusted model being obtained in accordance with the specific model in question such that the distance between the adjusted model and the reference model is minimal according to a given metric; and constructing (C), from the adjusted models obtained during the adjustment step (A), said model of the face of the person. The invention also proposes methods and devices for posture analysis using such a constructed model.