@article {18457,
	title = {Plane-Wave Decomposition of Acoustical Scenes Via Spherical and Cylindrical Microphone Arrays},
	journal = {IEEE Transactions on Audio, Speech, and Language Processing},
	volume = {18},
	year = {2010},
	month = {2010/01//},
	pages = {2 - 16},
	abstract = {Spherical and cylindrical microphone arrays offer a number of attractive properties such as direction-independent acoustic behavior and ability to reconstruct the sound field in the vicinity of the array. Beamforming and scene analysis for such arrays is typically done using sound field representation in terms of orthogonal basis functions (spherical/cylindrical harmonics). In this paper, an alternative sound field representation in terms of plane waves is described, and a method for estimating it directly from measurements at microphones is proposed. It is shown that representing a field as a collection of plane waves arriving from various directions simplifies source localization, beamforming, and spatial audio playback. A comparison of the new method with the well-known spherical harmonics based beamforming algorithm is done, and it is shown that both algorithms can be expressed in the same framework but with weights computed differently. It is also shown that the proposed method can be extended to cylindrical arrays. A number of features important for the design and operation of spherical microphone arrays in real applications are revealed. Results indicate that it is possible to reconstruct the sound scene up to order p with p2 microphones spherical array.},
	keywords = {Acoustic fields, acoustic position measurement, acoustic signal processing, acoustic waves, acoustical scene analysis, array signal processing, circular arrays, cylindrical microphone arrays, direction-independent acoustic behavior, microphone arrays, orthogonal basis functions, plane-wave decomposition, Position measurement, signal reconstruction, sound field reconstruction, sound field representation, source localization, spatial audio playback, spherical harmonics based beamforming algorithm, spherical microphone arrays},
	isbn = {1558-7916},
	doi = {10.1109/TASL.2009.2022000},
	author = {Zotkin,Dmitry N and Duraiswami, Ramani and Gumerov, Nail A.}
}
@conference {18467,
	title = {Regularized HRTF fitting using spherical harmonics},
	booktitle = {IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, 2009. WASPAA {\textquoteright}09},
	year = {2009},
	month = {2009/10//},
	pages = {257 - 260},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {By the Helmholtz reciprocity principle, the head-related transfer function (HRTF) is equivalent to an acoustic field created by a transmitter placed at the ear location. Therefore, it can be represented as a spherical harmonics spectrum - a weighted sum of spherical harmonics. Such representations are useful in theoretical and computational analysis. Many different (often severely undersampled) grids are used for HRTF measurement, making the spectral reconstruction difficult. In this paper, two methods of obtaining the spectrum are presented and analyzed both on synthetic (ground-truth data available) and real HRTF measurements.},
	keywords = {Acoustic applications, acoustic field, Acoustic fields, acoustic intensity measurement, Acoustic measurements, acoustic signal processing, Acoustic testing, acoustic waves, array signal processing, audio acoustics, circular arrays, computational analysis, Ear, ear location, head-related transfer function, Helmholtz reciprocity principle, HRTF, HRTF fitting, Loudspeakers, Microphones, Position measurement, signal reconstruction, spatial audio, spectral reconstruction, spherical harmonics, Transfer functions},
	isbn = {978-1-4244-3678-1},
	doi = {10.1109/ASPAA.2009.5346521},
	author = {Zotkin,Dmitry N and Duraiswami, Ramani and Gumerov, Nail A.}
}
@conference {11985,
	title = {Multiple View Image Reconstruction: A Harmonic Approach},
	booktitle = {IEEE Conference on Computer Vision and Pattern Recognition, 2007. CVPR {\textquoteright}07},
	year = {2007},
	month = {2007/06/17/22},
	pages = {1 - 8},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {This paper presents a new constraint connecting the signals in multiple views of a surface. The constraint arises from a harmonic analysis of the geometry of the imaging process and it gives rise to a new technique for multiple view image reconstruction. Given several views of a surface from different positions, fundamentally different information is present in each image, owing to the fact that cameras measure the incoming light only after the application of a low-pass filter. Our analysis shows how the geometry of the imaging is connected to this filtering. This leads to a technique for constructing a single output image containing all the information present in the input images.},
	keywords = {CAMERAS, filtering theory, Geometry, Harmonic analysis, Image reconstruction, imaging process geometry, Information filtering, Joining processes, Low pass filters, low-pass filter, low-pass filters, multiple view image reconstruction, Position measurement, Power harmonic filters, surface reconstruction},
	isbn = {1-4244-1180-7},
	doi = {10.1109/CVPR.2007.383285},
	author = {Domke, J. and Aloimonos, J.}
}
@conference {18480,
	title = {Frequency Independent Flexible Spherical Beamforming Via Rbf Fitting},
	booktitle = {2006 IEEE International Conference on Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings},
	volume = {5},
	year = {2006},
	month = {2006/05//},
	pages = {V-V - V-V},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {We describe a new method for sound analysis using a spherical microphone array without the use of quadrature over the sphere. Quadrature based solutions are very sensitive to the placement of microphones on the sphere, needing measurements to be made at exactly the quadrature positions. We propose to use fitting with band-limited radial basis functions (RBFs) rather than quadrature. Our approach results in frequency independent beamformer weights for flexibly placed microphone locations. Results are demonstrated using both synthetic and real spherical array data},
	keywords = {acoustic signal processing, array signal processing, band-limited radial basis functions, Computer science, Educational institutions, Eigenvalues and eigenfunctions, Equations, Frequency, frequency independent beamformer weights, frequency independent flexible spherical beamforming, microphone arrays, Nails, Position measurement, RBF fitting, Robustness, sound analysis, spherical array data, spherical microphone array},
	isbn = {1-4244-0469-X},
	doi = {10.1109/ICASSP.2006.1661208},
	author = {Yerukhimovich,A. and Duraiswami, Ramani and Gumerov, Nail A. and Zotkin,Dmitry N}
}
@article {18460,
	title = {Accelerated speech source localization via a hierarchical search of steered response power},
	journal = {IEEE Transactions on Speech and Audio Processing},
	volume = {12},
	year = {2004},
	month = {2004/09//},
	pages = {499 - 508},
	abstract = {Accurate and fast localization of multiple speech sound sources is a problem that is of significant interest in applications such as conferencing systems. Recently, approaches that are based on search for local peaks of the steered response power are becoming popular, despite their known computational expense. Based on the observation that the wavelengths of the sound from a speech source are comparable to the dimensions of the space being searched and that the source is broadband, we have developed an efficient search algorithm. Significant speedups are achieved by using coarse-to-fine strategies in both space and frequency. We present applications of the search algorithm to speed up simple delay-and-sum beamforming and steered response power phase-transform weighted (SRP-PHAT) source localization algorithms. A systematic series of comparisons with previous algorithms are made that show that the technique is much faster, robust, and accurate. The performance of the algorithm can be further improved by using constraints from computer vision.},
	keywords = {accelerated speech source localization, Acceleration, array signal processing, conferencing system, Delay, delay-and-sum beamforming, direction-of-arrival estimation, Frequency, hierarchical search algorithm, Inverse problems, multimedia applications, Multimedia communication, multiple speech sound source, Position measurement, Robustness, search problems, Sensor arrays, Signal processing algorithms, speech, speech enhancement, Speech processing, steered response power, steered response power phase-transform weighted source localization algorithm, transducer arrays, User interfaces},
	isbn = {1063-6676},
	doi = {10.1109/TSA.2004.832990},
	author = {Zotkin,Dmitry N and Duraiswami, Ramani}
}
@conference {18470,
	title = {Virtual audio system customization using visual matching of ear parameters},
	booktitle = {16th International Conference on Pattern Recognition, 2002. Proceedings},
	volume = {3},
	year = {2002},
	month = {2002///},
	pages = {1003- 1006 vol.3 - 1003- 1006 vol.3},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Applications in the creation of virtual auditory spaces (VAS) and sonification require individualized head related transfer functions (HRTFs) for perceptual fidelity. HRTFs exhibit significant variation from person to person due to differences between their pinnae, and their body sizes. We propose and preliminarily implement a simple HRTF customization based on the use of a published database of HRTFs (Algazi et al., 2001) that also contains geometrical measurements of subject pinnae. We measure some of these features via simple image processing, and select the HRTF that has features most closely corresponding to the individual{\textquoteright}s features. This selection procedure is implemented along with the virtual auditory system described in (Zotkin et al., 2002), and listener tests conducted comparing the customized HRTF and a fixed HRTF. Despite the simplicity of the method, tests reveal average improvement in localization accuracy of about 25 percent, though performance improvement varies with source location and individuals.},
	keywords = {acoustic signal processing, Audio systems, Auditory system, Computer vision, database, Ear, ear parameter matching, geometrical measurements, Head, head related transfer functions, HRTF customization, Image databases, IMAGE PROCESSING, medical image processing, performance improvement, Position measurement, sonification, Spatial databases, System testing, Transfer functions, virtual audio system customization, virtual auditory spaces, virtual auditory system, visual matching},
	isbn = {0-7695-1695-X},
	doi = {10.1109/ICPR.2002.1048207},
	author = {Zotkin,Dmitry N and Duraiswami, Ramani and Davis, Larry S. and Mohan,A. and Raykar,V.}
}
@conference {18466,
	title = {Active speech source localization by a dual coarse-to-fine search},
	booktitle = {2001 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2001. Proceedings. (ICASSP {\textquoteright}01)},
	volume = {5},
	year = {2001},
	month = {2001///},
	pages = {3309-3312 vol.5 - 3309-3312 vol.5},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Accurate and fast localization of multiple speech sound sources is a significant problem in videoconferencing systems. Based on the observation that the wavelengths of the sound from a speech source are comparable to the dimensions of the space being searched, and that the source is broadband, we develop an efficient search strategy that finds the source(s) in a given space. The search is made efficient by using coarse-to-fine strategies in both space and frequency. The algorithm is shown to be robust compared to typical delay-based estimators and fast enough for real-time implementation. Its performance can be further improved by using constraints from computer vision},
	keywords = {active speech source localization, array signal processing, Computer interfaces, Delay effects, delay estimation, delay-based estimators, dual coarse-to-fine search, Frequency, Inverse problems, Laboratories, multiple speech sound sources, Position measurement, real-time implementation, Sensor arrays, Signal processing algorithms, space, speech, Speech processing, Teleconferencing, videoconferencing systems},
	isbn = {0-7803-7041-4},
	doi = {10.1109/ICASSP.2001.940366},
	author = {Duraiswami, Ramani and Zotkin,Dmitry N and Davis, Larry S.}
}
@conference {18463,
	title = {An audio-video front-end for multimedia applications},
	booktitle = {2000 IEEE International Conference on Systems, Man, and Cybernetics},
	volume = {2},
	year = {2000},
	month = {2000///},
	pages = {786-791 vol.2 - 786-791 vol.2},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Applications such as video gaming, virtual reality, multimodal user interfaces and videoconferencing, require systems that can locate and track persons in a room through a combination of visual and audio cues, enhance the sound that they produce, and perform identification. We describe the development of a particular multimodal sensor fusion system that is portable, runs in real time and achieves these objectives. The system employs novel algorithms for acoustical source location, video-based person tracking and overall system control, which are also described},
	keywords = {Acoustic noise, acoustical source location, Application software, audio cues, audio-video front-end, CAMERAS, Computer vision, Microphones, multimedia applications, multimedia systems, multimodal sensor fusion system, multimodal user interfaces, Position measurement, REAL TIME, Real time systems, real-time systems, sensor fusion, sound, Speech recognition, User interfaces, video cameras, video gaming, video-based person tracking, Videoconference, videoconferencing, Virtual reality, visual cues, Working environment noise},
	isbn = {0-7803-6583-6},
	doi = {10.1109/ICSMC.2000.885945},
	author = {Zotkin,Dmitry N and Duraiswami, Ramani and Davis, Larry S. and Haritaoglu,I.}
}
