Matching pursuit (MP) video coding has been demonstrated to attain a better coding performance than DCT-based video coding in terms of PSNR and perceptual quality at very low bit rates. However, because of its massive...
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Matching pursuit (MP) video coding has been demonstrated to attain a better coding performance than DCT-based video coding in terms of PSNR and perceptual quality at very low bit rates. However, because of its massive computational complexity, the MP algorithm is usually only approximated. By approximating a residual in a subspace, we propose a multiple blocks search and update algorithm in MP video coding to achieve a faster and better MP approximation. In this paper, we evaluate the performance and compare it to the traditional one-block search algorithms. The experimental results show that our proposed algorithm can significantly improve the coding performance and encoding time.
The orthogonal matching pursuit (OMP) algorithm is an adaptive nonlinear algorithm for signal decomposition using an overcomplete dictionary. A tree-search based orthogonal matching pursuit (TB-OMP) has been proposed ...
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The orthogonal matching pursuit (OMP) algorithm is an adaptive nonlinear algorithm for signal decomposition using an overcomplete dictionary. A tree-search based orthogonal matching pursuit (TB-OMP) has been proposed (Cotter et al. (2001)). Although the TB-OMP algorithm improves the approximation performance, its computation time requirement increases exponentially making the algorithm impractical for certain applications. In this paper, we propose the flexible tree-search based orthogonal matching pursuit (FTB-OMP). The algorithm provides design parameters that give flexibility to establish a tradeoff between approximation performance and experimental time complexity. Sparse signal representations are frequently required in problems related to signal processing and communication areas. The proposed FTB-OMP algorithm is a promising solution for such problems.
In this paper we have presented the MP algorithm as an alternative method for Gaussian beam decomposition. The results of the numerical example indicate that this type of WFT frame expansion produces a substantial imp...
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In this paper we have presented the MP algorithm as an alternative method for Gaussian beam decomposition. The results of the numerical example indicate that this type of WFT frame expansion produces a substantial improvement in the quality of the reconstructed field in terms of both the number of expansion coefficients and the relative error. However one major drawback of the MP algorithm is its computational complexity. Compared to the dual frame, the MP algorithm always appears to be time consuming.
In the framework of audio signal analysis, it is desired to obtain sparse representations that are able to reflect the harmonic structures, e.g., issued from musical instruments. In this paper, we compare two approach...
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In the framework of audio signal analysis, it is desired to obtain sparse representations that are able to reflect the harmonic structures, e.g., issued from musical instruments. In this paper, we compare two approaches which introduce some explicit models of harmonic features into the matching pursuit analysis framework. The first approach is the harmonic matching pursuit (HMP), where the harmonic structures are modeled by sets of harmonically related Gabor atoms which are directly optimized in the analysis loop. The second approach, called meta-molecular matching pursuit (M3P), is based on the a posteriori agglomeration of elementary features coming from a short time Fourier transform. We discuss the pros and cons of each method through experiments involving different audio signals, and conclude on possible approaches for combining the two methods.
This paper describes a simple, straightforward algorithm for flying in formation of multiple unmanned air vehicles (UAV's). In particular, we are interested in a formation with no communication between the vehicle...
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This paper describes a simple, straightforward algorithm for flying in formation of multiple unmanned air vehicles (UAV's). In particular, we are interested in a formation with no communication between the vehicles. It is assumed that relative kinematics parameters are available to each UAV from an on-board passive sensor followed by estimation processes and a controller which may use visual information. The paper introduces a guidance algorithm, which is based on the theory of pursuit curves in conjunction with a velocity controller.
Matching pursuit has found many applications recently especially in very low bit rate video coding. In this paper we show how the complexity of matching pursuit can be reduced from O(N) to O(log(2N)) using tree struct...
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Matching pursuit has found many applications recently especially in very low bit rate video coding. In this paper we show how the complexity of matching pursuit can be reduced from O(N) to O(log(2N)) using tree structured dictionaries. Moreover, we show how tree structured dictionaries provide an efficient coding strategy that is more resilient to error than random coding. Our simulation results showed an improvement of about 3 dB in PSNR can be achieved using the code provided by the tree structured dictionary.
This paper describes a general design method for signal dependent frames, or over-complete dictionaries. The design method is developed for block-oriented frames, overlapping frames, and constrained frames, which can ...
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This paper describes a general design method for signal dependent frames, or over-complete dictionaries. The design method is developed for block-oriented frames, overlapping frames, and constrained frames, which can be regarded as extensions of, respectively, block-oriented transforms, filter banks, and general filter banks like wavelets. The frames are optimized for sparse representation of a signal class. Using the designed frames and a matching pursuit algorithm it is shown that superior, compared to other methods, sparse representations are achieved for an electrocardiogram signal. It is also demonstrated that compression based on these sparse representations gives excellent performance at low bit rates.
In this paper, we propose a novel system architecture that employs the flexible tree search based orthogonal matching pursuit (FTB-OMP) algorithm for direction of arrival estimation. It is shown by simulation results ...
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In this paper, we propose a novel system architecture that employs the flexible tree search based orthogonal matching pursuit (FTB-OMP) algorithm for direction of arrival estimation. It is shown by simulation results that the FTB-OMP algorithm has high estimation performance and resolution capability when compared to the MUSIC and OMP algorithms. The proposed system does not require a priori knowledge on the number of directions to be resolved and uses very small amount of snapshots for convergence. It is also superior to the ESPRIT algorithm since ESPRIT cannot resolve angles that are separated more than a threshold.
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