The problem of automatic key signature detection has been the focus of much research in recent ye... more The problem of automatic key signature detection has been the focus of much research in recent years. Previous methods of key estimation have focused on chromagrams and key profiling techniques. This paper presents a remarkably simple but effective method of estimating key signature from musical recordings. The algorithm introduces the 'keyogram', a concept resembling the chromagram, and is aimed for use on traditional Irish music. The keyogram is a measure of the likelihood of each possible major key signature based on a masked scoring system.
2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2006
Recently, shifted Non-negative Matrix Factorisation was developed as a means of separating harmon... more Recently, shifted Non-negative Matrix Factorisation was developed as a means of separating harmonic instruments from single channel mixtures. However, in many cases two or more channels are available, in which case it would be advantageous to have a multichannel version of the algorithm. To this end, a shifted Non-negative Tensor Factorisation algorithm is derived, which extends shifted Non-negative Matrix Factorisation to the multi-channel case. The use of this algorithm for multi-channel sound source separation of harmonic instruments is demonstrated. Further, it is shown that the algorithm can be used to perform Non-negative Tensor Deconvolution, a multi-channel version of Non-negative Matrix Deconvolution, to separate sound sources which have time evolving spectra from multi-channel signals.
IET Irish Signals and Systems Conference (ISSC 2009), 2009
Non-negative Tensor Factorisation based methods have found use in the context of musical sound so... more Non-negative Tensor Factorisation based methods have found use in the context of musical sound source separation. These techniques require the use of a suitable cost function to determine the optimal factorisation, and most work has focused on the use of the generalised Kullback-Liebler divergence, and more recently the Itakura-Saito divergence. These divergences can be regarded as limiting cases of the parameterised Beta divergence. This paper looks at the use of the Beta Divergence in the context of musical source separation with a view to determining an optimal value of Beta for this problem. This is considered for both magnitude and power spectrograms. In an effort to avoid potential local minima in the Beta divergence, the use of a "tempered" Beta Divergence is also explored.
IET Irish Signals and Systems Conference (ISSC 2006), 2006
Recently, Non-negative Matrix Factor 2D Deconvolution was developed as a means of separating harm... more Recently, Non-negative Matrix Factor 2D Deconvolution was developed as a means of separating harmonic instruments from single channel mixtures. This technique uses a model which is convolutive in both time and frequency, and so can capture instruments which have both time-varying spectra and timevarying fundamental frequencies simultaneously. However, in many cases two or more channels are available, in which case it would be advantageous to have a multi-channel version of the algorithm. To this end, a shifted 2D Non-negative Tensor Factorisation algorithm is derived, which extends Non-negative Matrix Factor 2D Deconvolution to the multi-channel case. The use of this algorithm for multi-channel sound source separation of pitched instruments is demonstrated.
IET Irish Signals and Systems Conference (ISSC 2008), 2008
The Adress algorithm has proved successful as a means of separating sound sources from stereo mix... more The Adress algorithm has proved successful as a means of separating sound sources from stereo mixtures. The algorithm has two main parameters, azimuth position and azimuth width, and these are typically set by the user for each source individually. For the separation of large amounts of audio material, such as in an audio archive, a method of automatically setting these parameters would be of use. This paper proposes a method of automatically obtaining the azimuth widths for the sources in a mixture by balancing the reconstruction error between the original spectrograms and the resynthesised spectrograms with the sparseness of the recovered sources, using an L-curve type approach.
2010 IEEE International Conference on Multimedia and Expo, 2010
The goal of the Interactive Music Archive Access System (IMAAS) project was to develop an interac... more The goal of the Interactive Music Archive Access System (IMAAS) project was to develop an interactive music archive access system which was capable of allowing an end-user to easily extract rhythmic, melodic and harmonic musical metadata descriptors from audio, and allow the user to interact with the archive contents in a manner not typically allowed in archive access systems. To this end, the IMAAS system incorporates a range of real-time interaction tools which allow the user to modify the retrieved audio in a number of ways including the ability to isolate individual instruments in stereo mixes, pitch and timescale modification, and beat-synchronous looping. This demo gives an overview of the capabilities of the IMAAS application.
Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of ... more Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.
The problem of automatic key signature detection has been the focus of much research in recent ye... more The problem of automatic key signature detection has been the focus of much research in recent years. Previous methods of key estimation have focused on chromagrams and key profiling techniques. This paper presents a remarkably simple but effective method of estimating key signature from musical recordings. The algorithm introduces the 'keyogram', a concept resembling the chromagram, and is aimed for use on traditional Irish music. The keyogram is a measure of the likelihood of each possible major key signature based on a masked scoring system.
An algorithm for Non-negative Tensor Factorisation is introduced which extends current matrix fac... more An algorithm for Non-negative Tensor Factorisation is introduced which extends current matrix factorisation techniques to deal with tensors. The effectiveness of the algorithm is then demonstrated through tests on synthetic data. The algorithm is then employed as a means of performing sound source separation on two channel mixtures, and the separation capabilities of the algorithm demonstrated on a two channel mixture containing saxophone, strings and bass guitar.
A shift-invariant non-negative tensor factorisation algorithm for musical source separation is pr... more A shift-invariant non-negative tensor factorisation algorithm for musical source separation is proposed which generalises previous work by allowing each source to have its own parameters rather a fixed set of parameters for all sources. This allows independent control of the number of allowable notes, number of harmonics and shifts in time for each source. This increased flexibility allows the incorporation of further information about the sources and results in improved separation and resynthesis of the separated sources.
The problem of automatic key signature detection has been the focus of much research in recent ye... more The problem of automatic key signature detection has been the focus of much research in recent years. Previous methods of key estimation have focused on chromagrams and key profiling techniques. This paper presents a remarkably simple but effective method of estimating key signature from musical recordings. The algorithm introduces the 'keyogram', a concept resembling the chromagram, and is aimed for use on traditional Irish music. The keyogram is a measure of the likelihood of each possible major key signature based on a masked scoring system.
2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2006
Recently, shifted Non-negative Matrix Factorisation was developed as a means of separating harmon... more Recently, shifted Non-negative Matrix Factorisation was developed as a means of separating harmonic instruments from single channel mixtures. However, in many cases two or more channels are available, in which case it would be advantageous to have a multichannel version of the algorithm. To this end, a shifted Non-negative Tensor Factorisation algorithm is derived, which extends shifted Non-negative Matrix Factorisation to the multi-channel case. The use of this algorithm for multi-channel sound source separation of harmonic instruments is demonstrated. Further, it is shown that the algorithm can be used to perform Non-negative Tensor Deconvolution, a multi-channel version of Non-negative Matrix Deconvolution, to separate sound sources which have time evolving spectra from multi-channel signals.
IET Irish Signals and Systems Conference (ISSC 2009), 2009
Non-negative Tensor Factorisation based methods have found use in the context of musical sound so... more Non-negative Tensor Factorisation based methods have found use in the context of musical sound source separation. These techniques require the use of a suitable cost function to determine the optimal factorisation, and most work has focused on the use of the generalised Kullback-Liebler divergence, and more recently the Itakura-Saito divergence. These divergences can be regarded as limiting cases of the parameterised Beta divergence. This paper looks at the use of the Beta Divergence in the context of musical source separation with a view to determining an optimal value of Beta for this problem. This is considered for both magnitude and power spectrograms. In an effort to avoid potential local minima in the Beta divergence, the use of a "tempered" Beta Divergence is also explored.
IET Irish Signals and Systems Conference (ISSC 2006), 2006
Recently, Non-negative Matrix Factor 2D Deconvolution was developed as a means of separating harm... more Recently, Non-negative Matrix Factor 2D Deconvolution was developed as a means of separating harmonic instruments from single channel mixtures. This technique uses a model which is convolutive in both time and frequency, and so can capture instruments which have both time-varying spectra and timevarying fundamental frequencies simultaneously. However, in many cases two or more channels are available, in which case it would be advantageous to have a multi-channel version of the algorithm. To this end, a shifted 2D Non-negative Tensor Factorisation algorithm is derived, which extends Non-negative Matrix Factor 2D Deconvolution to the multi-channel case. The use of this algorithm for multi-channel sound source separation of pitched instruments is demonstrated.
IET Irish Signals and Systems Conference (ISSC 2008), 2008
The Adress algorithm has proved successful as a means of separating sound sources from stereo mix... more The Adress algorithm has proved successful as a means of separating sound sources from stereo mixtures. The algorithm has two main parameters, azimuth position and azimuth width, and these are typically set by the user for each source individually. For the separation of large amounts of audio material, such as in an audio archive, a method of automatically setting these parameters would be of use. This paper proposes a method of automatically obtaining the azimuth widths for the sources in a mixture by balancing the reconstruction error between the original spectrograms and the resynthesised spectrograms with the sparseness of the recovered sources, using an L-curve type approach.
2010 IEEE International Conference on Multimedia and Expo, 2010
The goal of the Interactive Music Archive Access System (IMAAS) project was to develop an interac... more The goal of the Interactive Music Archive Access System (IMAAS) project was to develop an interactive music archive access system which was capable of allowing an end-user to easily extract rhythmic, melodic and harmonic musical metadata descriptors from audio, and allow the user to interact with the archive contents in a manner not typically allowed in archive access systems. To this end, the IMAAS system incorporates a range of real-time interaction tools which allow the user to modify the retrieved audio in a number of ways including the ability to isolate individual instruments in stereo mixes, pitch and timescale modification, and beat-synchronous looping. This demo gives an overview of the capabilities of the IMAAS application.
Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of ... more Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.
The problem of automatic key signature detection has been the focus of much research in recent ye... more The problem of automatic key signature detection has been the focus of much research in recent years. Previous methods of key estimation have focused on chromagrams and key profiling techniques. This paper presents a remarkably simple but effective method of estimating key signature from musical recordings. The algorithm introduces the 'keyogram', a concept resembling the chromagram, and is aimed for use on traditional Irish music. The keyogram is a measure of the likelihood of each possible major key signature based on a masked scoring system.
An algorithm for Non-negative Tensor Factorisation is introduced which extends current matrix fac... more An algorithm for Non-negative Tensor Factorisation is introduced which extends current matrix factorisation techniques to deal with tensors. The effectiveness of the algorithm is then demonstrated through tests on synthetic data. The algorithm is then employed as a means of performing sound source separation on two channel mixtures, and the separation capabilities of the algorithm demonstrated on a two channel mixture containing saxophone, strings and bass guitar.
A shift-invariant non-negative tensor factorisation algorithm for musical source separation is pr... more A shift-invariant non-negative tensor factorisation algorithm for musical source separation is proposed which generalises previous work by allowing each source to have its own parameters rather a fixed set of parameters for all sources. This allows independent control of the number of allowable notes, number of harmonics and shifts in time for each source. This increased flexibility allows the incorporation of further information about the sources and results in improved separation and resynthesis of the separated sources.
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Papers by Matt Cranitch