2016 IEEE International Workshop on Acoustic Signal Enhancement (IWAENC), 2016
This manuscript presents a robust data-independent near-field beamformer using a linear microphon... more This manuscript presents a robust data-independent near-field beamformer using a linear microphone array. We consider a scenario with a desired sound source and an interferer; our goal in this manuscript is to provide a technique to extract the desired source signal while attenuating the interferer. We formulate the beamformer design problem as a convex optimization problem with additional constraints that aim at controlling the spatial response of the beamformer, with emphasis on the robustness of the approach to errors in the localization of the interferer sound source. We validate our approach through simulations.
In this paper we propose a method for reducing the impact of room reflections in sound field rend... more In this paper we propose a method for reducing the impact of room reflections in sound field rendering applications. Our method is based on the modeling of the acoustic paths (direct and reflected) from each of the loudspeakers of the rendering system, and a set of control points in the listening area. From such models we derive a propagation matrix and compute its least-squares inversion. Due to its relevant impact on the spatial impression, we focus on the early reflections part of the Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares problem is formulated in order to derive the compensation filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.
In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echo... more In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echoes on the perceived quality in soundfield rendering applications. These metrics are derived from psychoacoustic-based considerations, in particular the masking effect, well known in the literature of perceptual coding. The measurement is accomplished through a virtual microphone array that samples the soundfield on a circumference. The soundfield within the circle is estimated by means of the circular harmonic decomposition. ...
2013 IEEE 15th International Workshop on Multimedia Signal Processing (MMSP), 2013
ABSTRACT We compare two paradigms for image analysis in visual sensor networks (VSN). In the comp... more ABSTRACT We compare two paradigms for image analysis in visual sensor networks (VSN). In the compress-then-analyze (CTA) paradigm, images acquired from camera nodes are compressed and sent to a central controller for further analysis. Conversely, in the analyze-then-compress (ATC) approach, camera nodes perform visual feature extraction and transmit a compressed version of these features to a central controller. We focus on state-of-the-art binary features which are particularly suitable for resource-constrained VSNs, and we show that the “winning” paradigm depends primarily on the network conditions. Indeed, while the ATC approach might be the only possible way to perform analysis at low available bitrates, the CTA approach reaches the best results when the available bandwidth enables the transmission of high-quality images.
In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echo... more In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echoes on the perceived quality in soundfield rendering applications. These metrics are derived from psychoacoustic-based considerations, in particular the masking effect, well known in the literature of perceptual coding. The measurement is accomplished through a virtual microphone array that samples the soundfield on a circumference.
In this paper we propose a method for reducing the impact of
room reflections in sound field rend... more In this paper we propose a method for reducing the impact of room reflections in sound field rendering applications. Our method is based on the modeling of the acoustic paths (direct and reflected) from each of the loudspeakers of the rendering system, and a set of control points in the listening area. From such models we derive a propagation matrix and compute its least-squares inversion. Due to its relevant impact on the spatial impression, we focus on the early reflections part of the Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares problem is formulated in order to derive the compensation filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.
In this paper we propose a robust beamforming technique which takes into account uncertainties an... more In this paper we propose a robust beamforming technique which takes into account uncertainties and variations in the radiation pattern of the loudspeakers. The proposed technique is based on the solution of a robust least-square problem in which the propagation matrix is to some extent unknown. Both simulations and experimental results prove the validity of the proposed methodology in terms of directivity index and white noise gain.
In this paper we propose a methodology aimed at improving the resolution capabilities of plenacou... more In this paper we propose a methodology aimed at improving the resolution capabilities of plenacoustic imaging, which is based on deconvolution techniques mutuated from aerospace acoustic imaging. In order to reduce the computational burden, we also propose a modification of the minimization problem that exploits the highly structured information contained in the plenacoustic image. Experiments and simulations show the improvement of the accuracy gained by applying the deconvolution operator.
2016 IEEE International Workshop on Acoustic Signal Enhancement (IWAENC), 2016
This manuscript presents a robust data-independent near-field beamformer using a linear microphon... more This manuscript presents a robust data-independent near-field beamformer using a linear microphone array. We consider a scenario with a desired sound source and an interferer; our goal in this manuscript is to provide a technique to extract the desired source signal while attenuating the interferer. We formulate the beamformer design problem as a convex optimization problem with additional constraints that aim at controlling the spatial response of the beamformer, with emphasis on the robustness of the approach to errors in the localization of the interferer sound source. We validate our approach through simulations.
In this paper we propose a method for reducing the impact of room reflections in sound field rend... more In this paper we propose a method for reducing the impact of room reflections in sound field rendering applications. Our method is based on the modeling of the acoustic paths (direct and reflected) from each of the loudspeakers of the rendering system, and a set of control points in the listening area. From such models we derive a propagation matrix and compute its least-squares inversion. Due to its relevant impact on the spatial impression, we focus on the early reflections part of the Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares problem is formulated in order to derive the compensation filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.
In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echo... more In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echoes on the perceived quality in soundfield rendering applications. These metrics are derived from psychoacoustic-based considerations, in particular the masking effect, well known in the literature of perceptual coding. The measurement is accomplished through a virtual microphone array that samples the soundfield on a circumference. The soundfield within the circle is estimated by means of the circular harmonic decomposition. ...
2013 IEEE 15th International Workshop on Multimedia Signal Processing (MMSP), 2013
ABSTRACT We compare two paradigms for image analysis in visual sensor networks (VSN). In the comp... more ABSTRACT We compare two paradigms for image analysis in visual sensor networks (VSN). In the compress-then-analyze (CTA) paradigm, images acquired from camera nodes are compressed and sent to a central controller for further analysis. Conversely, in the analyze-then-compress (ATC) approach, camera nodes perform visual feature extraction and transmit a compressed version of these features to a central controller. We focus on state-of-the-art binary features which are particularly suitable for resource-constrained VSNs, and we show that the “winning” paradigm depends primarily on the network conditions. Indeed, while the ATC approach might be the only possible way to perform analysis at low available bitrates, the CTA approach reaches the best results when the available bandwidth enables the transmission of high-quality images.
In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echo... more In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echoes on the perceived quality in soundfield rendering applications. These metrics are derived from psychoacoustic-based considerations, in particular the masking effect, well known in the literature of perceptual coding. The measurement is accomplished through a virtual microphone array that samples the soundfield on a circumference.
In this paper we propose a method for reducing the impact of
room reflections in sound field rend... more In this paper we propose a method for reducing the impact of room reflections in sound field rendering applications. Our method is based on the modeling of the acoustic paths (direct and reflected) from each of the loudspeakers of the rendering system, and a set of control points in the listening area. From such models we derive a propagation matrix and compute its least-squares inversion. Due to its relevant impact on the spatial impression, we focus on the early reflections part of the Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares problem is formulated in order to derive the compensation filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.
In this paper we propose a robust beamforming technique which takes into account uncertainties an... more In this paper we propose a robust beamforming technique which takes into account uncertainties and variations in the radiation pattern of the loudspeakers. The proposed technique is based on the solution of a robust least-square problem in which the propagation matrix is to some extent unknown. Both simulations and experimental results prove the validity of the proposed methodology in terms of directivity index and white noise gain.
In this paper we propose a methodology aimed at improving the resolution capabilities of plenacou... more In this paper we propose a methodology aimed at improving the resolution capabilities of plenacoustic imaging, which is based on deconvolution techniques mutuated from aerospace acoustic imaging. In order to reduce the computational burden, we also propose a modification of the minimization problem that exploits the highly structured information contained in the plenacoustic image. Experiments and simulations show the improvement of the accuracy gained by applying the deconvolution operator.
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Papers by Lucio Bianchi
room reflections in sound field rendering applications. Our
method is based on the modeling of the acoustic paths (direct
and reflected) from each of the loudspeakers of the rendering
system, and a set of control points in the listening area. From
such models we derive a propagation matrix and compute its
least-squares inversion. Due to its relevant impact on the spatial
impression, we focus on the early reflections part of the
Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares
problem is formulated in order to derive the compensation
filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.
room reflections in sound field rendering applications. Our
method is based on the modeling of the acoustic paths (direct
and reflected) from each of the loudspeakers of the rendering
system, and a set of control points in the listening area. From
such models we derive a propagation matrix and compute its
least-squares inversion. Due to its relevant impact on the spatial
impression, we focus on the early reflections part of the
Room Impulse Response, which is conveniently estimated using the fast beam tracing modeling engine. A least squares
problem is formulated in order to derive the compensation
filter. We also demonstrate the robustness of the proposed solution against errors in geometric measurement of the hosting environment.