Facial Feature Tracking Refinement via Motion Vector Smoothing

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Solution Overview

Problem

Existing augmented reality systems face errors in tracking facial features, leading to a suboptimal user experience due to inaccuracies in feature point displacement.

Innovation Solution

A computing device determines the location of a feature point in successive frames, generates a motion vector, and refines the location using a refinement module, then generates a smoothed location based on the refined and actual locations in subsequent frames, employing a cascaded regression-based facial landmark detection method.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional facial feature tracking methods are used in augmented reality systems, then the system complexity remains low, but the tracking accuracy and reliability deteriorate due to errors in determining feature point displacement

Engineering Contradiction:
Improvetracking accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The tracking system is divided into multiple independent modules: a detection module that identifies feature points in each frame, a motion vector generation module that calculates displacement, and a refinement module that smooths the trajectory. This segmentation allows each module to specialize in one function, improving overall tracking accuracy while keeping individual modules computationally efficient

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system generates motion vectors based on detected feature points before final positioning is determined. By preliminary calculating the displacement vectors and then refining them through smoothing operations, the system prepares accurate position data in advance, improving tracking precision without requiring overly complex real-time processing

Inventive Principle:
Principle #10Preliminary action

2Reliability

If simple feature point detection is used, then the processing speed remains high, but the reliability of feature point location deteriorates due to inaccuracies in displacement determination

Engineering Contradiction:
Improvefeature point location accuracyVSAvoidprocessing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The refinement module uses feedback from multiple consecutive frames to adjust and smooth the feature point trajectory. By continuously comparing detected positions with previously refined positions and adjusting accordingly, the system improves location reliability while maintaining efficient processing through iterative refinement rather than complex single-frame analysis

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the parameter representation of feature points from raw detected coordinates to refined coordinates that incorporate motion vector information. By transforming the position data through multiple processing stages (detection → motion vector calculation → refinement), the system improves reliability without requiring excessively complex operations at any single stage

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10685213B2Systems and methods for tracking facial features
Publication Date: 2020.06.16 PERFECT CORP
  • US10685213B2 patent drawing
  • US10685213B2 patent drawing
  • US10685213B2 patent drawing

AI summary

A computing device determines, in a first frame, a first location of a feature point and also determines in a second frame, a second location of the feature point. The computing device generates a motion vector for the feature point in the first frame and relocates the first location in the first frame to a first refined location based on the motion vector. The computing device generates a smoothed location of the feature point in the second frame based on the refined location and the second location of the feature point in the second frame.