Non-Parametric HRTF Personalization via 3D Head Scan Harmonic Matching

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Solution Overview

Problem

Existing HRTF personalization systems face challenges in efficiently generating personalized audio experiences due to anthropometric variability among human subjects, requiring time-consuming and expensive measurements under anechoic conditions, and struggling with precise ITD modeling for accurate spatial rendering.

Innovation Solution

The system employs non-parametric processing of 3D head scans to identify the most similar head shape from a database, applying a 3D transform to generate personalized HRTFs using harmonic expansions, such as spherical Fourier-Bessel and harmonic oscillator transforms, for effective HRTF personalization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional HRTF measurement methods are used, then measurement precision is improved, but measurement time and cost increase significantly

Engineering Contradiction:
ImproveHRTF measurement precisionVSAvoidMeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates a database of training subjects with pre-measured HRTFs and uses 3D head scans to copy geometric features. Instead of measuring every user directly, the system finds the closest matching training subject whose HRTF data can be transferred to the new user, thus avoiding time-consuming measurements while maintaining precision.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces 3D head scan geometry as an intermediary between the user and the HRTF measurement process. The head scan serves as a mediator to identify matching training subjects, allowing the system to indirectly obtain personalized HRTFs without direct acoustic measurement of each user.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional HRTF personalization methods are used, then personalization accuracy is improved, but device complexity increases

Engineering Contradiction:
ImprovePersonalization accuracyVSAvoidSystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex acoustic measurement equipment and manual measurement processes with computational methods. The system uses 3D scanning, geometric transformation, and database matching algorithms to achieve personalization, substituting physical measurement complexity with computational simplicity.

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

Solution Approach 2:

The patent performs preliminary actions by pre-measuring and storing HRTF data for multiple training subjects in a database before actual use. This advance preparation allows the system to quickly match and retrieve appropriate HRTFs for new users without requiring complex real-time measurements.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If non-parametric processing of head geometry is used, then processing efficiency is improved, but measurement precision may be compromised

Engineering Contradiction:
ImproveProcessing efficiencyVSAvoidHead geometry measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent transforms 3D head scan data into harmonic expansions (spherical harmonic coefficients) as a new parameter representation. This transformation maintains the essential geometric information while enabling efficient comparison and matching operations, achieving both speed and accuracy through the changed parameter space.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent moves from the spatial domain (3D head scan geometry) to the frequency domain (harmonic expansion coefficients). This dimensional transformation allows for efficient computational operations while preserving the critical geometric features needed for accurate HRTF personalization.

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

Data Source

PatentUS10278002B2Systems and methods for non-parametric processing of head geometry for HRTF personalization
Publication Date: 2019.04.30 MICROSOFT TECHNOLOGY LICENSING LLC
  • US10278002B2 patent drawing
  • US10278002B2 patent drawing
  • US10278002B2 patent drawing

AI summary

Systems and methods for HRTF personalization are provided. More specifically, the systems and methods provide HRTF personalization utilizing non-parametric processing of three-dimensional head scans. Accordingly, the systems and methods for HRTF personalization generate a personalized set of HRTFs for a user without having to extract specific geometric and/or anthropometric features from a three dimensional head scan of a user and/or from the three dimensional head scans of training subjects in a database.