DOI QR코드

DOI QR Code

Interpolation method of head-related transfer function based on the least squares method and an acoustic modeling with a small number of measurement points

최소자승법과 음향학적 모델링 기반의 적은 개수의 측정점에 대한 머리전달함수 보간 기법

  • Lee, Seokjin (Department of Electronic Engineering, Kyoggi University)
  • 이석진 (경기대학교 전자공학과)
  • Received : 2017.08.01
  • Accepted : 2017.09.28
  • Published : 2017.09.30

Abstract

In this paper, an interpolation method of HRTF (Head-Related Transfer Function) is proposed for small-sized measurement data set, especially. The proposed algorithm is based on acoustic modeling of HRTFs, and the algorithm tries to interpolate the HRTFs via estimation the model coefficients. However, the estimation of the model coefficients is hard if there is lack of measurement points, so the algorithm solves the problem by a data augmentation using the VBAP (Vector Based Amplitude Panning). Therefore, the proposed algorithm consists of two steps, which are data augmentation step based on VBAP and model coefficients estimation step by least squares method. The proposed algorithm was evaluated by a simulation with a measured data from CIPIC (Center for Image Processing and Integrated Computing) HRTF database, and the simulation results show that the proposed algorithm reduces mean-squared error by 1.5 dB ~ 4 dB than the conventional algorithms.

본 논문에서는 머리전달함수 보간 알고리즘을 제안하며, 특히 작은 크기의 측정 데이터를 다루는 경우를 고려한다. 제안하는 알고리즘은 머리전달함수의 음향학적 모델링에 기초하며, 모델링 계수를 추정함으로써 머리전달함수를 보간한다. 이 때 측정 위치의 개수가 부족할 경우 모델링 계수를 추정하는 것은 매우 어려우며, 따라서 본 알고리즘은 벡터-기반 크기 패닝 기법을 이용하여 데이터를 확장함으로써 이러한 문제를 해결하려고 한다. 본 알고리즘은 벡터-기반 크기 패닝 기법 기반의 데이터 확장 단계와, 최소자승법 기반의 모델링 계수 추정 단계의 두 단계로 이루어져 있다. 제안하는 알고리즘의 성능을 확인하기 위하여 CIPIC(Center for Image Processing and Integrated Computing) 머리전달함수 데이터베이스의 측정 데이터 중 일부를 이용한 시뮬레이션을 진행하였으며, 시뮬레이션 결과 약 1.5 dB ~ 4 dB의 최소 자승 오차가 감소됨을 확인할 수 있었다.

Keywords

References

  1. ITU-R Recommendation BS.775-3, Multichannel Stereophonic Sound System with and without Accompanying Picture, 2012.
  2. J. Herre, J. Hilbert, A. Kuntz, and J. Plogsties, "MPEG-H audio - the new standard for universal spatial/3D audio coding," J. Audio. Eng. Soc. 62, 821-830 (2015). https://doi.org/10.17743/jaes.2014.0049
  3. ITU-R Recommendation BS.2051, Advanced Sound System for Programme Production, 2014.
  4. R. Duraiswaini, D. N. Zotkin, and N. A. Gumerov, "Interpolation and range extrapolation of HRTFs," Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing 2004 (ICASSP'04), 45-48 (2004).
  5. D. N. Zotkin, R. Duraiswaini, and N. A. Gumerov, "Regularized HRTF fitting using spherical harmonics," IEEE Workshop on Applications of Signal Processing to Audio and Acoustics 2009 (WASPAA'09), 257-260 (2009).
  6. H. Gamper, "Selection and interpolation of head-related transfer functions for rendering moving virtual sound sources," Proc. of the 16th Int. Conference on Digital Audio Effects, DAFx-16, (2013).
  7. K. S. Lee and S. P. Lee, "HRTF Interpolation Using a Spherical Head Model," (in Korean), J. Acoust. Soc. Kr. 333-341 (2008).
  8. V. Pulkki, "Virtual sound source positioning using vector base amplitude panning," J. Audio. Eng. Soc. 45, 456-466 (1997).
  9. H. Kuttruff, Acoustics: An Introduction (Taylor & Francis, New York, 2007), pp. 69-74.
  10. V. R. Algazi, R. O. Duda, D. M. Thompson, and C. Avendano, "The Cipic HRTF database," IEEE Workshop on the Applications of Signal Processing to Audio and Acoustics 2001 (WASPAA'01), 99-102 (2001).