Luis Mancera

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In recent years, Bayes least squares-Gaussian scale mixtures (BLS-GSM) has emerged as one of the most powerful methods for image restoration. Its strength relies on providing a simple and, yet, very effective local statistical description of oriented pyramid coefficient neighborhoods via a GSM vector. This can be viewed as a fine adaptation of the model to(More)
We present a simple and robust method for finding sparse representations in overcomplete transforms, based on minimization of the L0-norm. Our method is better than current solutions based on minimization of the L1-norm in terms of energy compaction. These results strongly question the equivalence of minimizing both norms in real conditions. We also show(More)
We propose a new formulation to the sparse approximation problem for the case of tight frames which allows to minimize the cost function using gradient descent. We obtain a generalized version of the iterative hard thresholding (IHT) algorithm, which provides locally optimal solutions. In addition, to avoid non-favorable minima we use an annealing technique(More)
In this paper, we propose a novel algorithm for image reconstruction from compressive measurements of wavelet coefficients. By incorporating independent Laplace priors on separate wavelet sub-bands, the inhomogeneity of wavelet coefficient distributions and therefore the structural sparsity within images are modeled effectively. We model the problem by(More)
We describe a method for removing quantization artifacts (de-quantizing) in the image domain, by enforcing a high degree of sparse-ness in its representation with an overcomplete oriented pyramid. For this purpose we devise a linear operator that returns the minimum L2-norm image preserving a set of significant coefficients, and estimate the original by(More)
We present a new image restoration method based on modelling the coefficients of an overcomplete wavelet response to natural images with a mixture of two Gaussian distributions, having non-zero and zero mean respectively, and reflecting the assumption that this response is close to be sparse. Including the observation model, the resulting procedure iterates(More)
We propose a novel Bayesian formulation for the reconstruction from compressed measurements. We demonstrate that high-sparsity enforcing priors based on l<sub>p</sub>-norms, with 0 &lt;; p &#x2264; 1, can be used within a Bayesian framework by majorization-minimization methods. By employing a fully Bayesian analysis of the compressed sensing system and a(More)
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) becomes the method of choice for the rapid identification of microorganisms (i.e. protein biotyping). Although bacterial identification is already quite advanced, biotyping of other microbes including yeasts and fungi are still under development. In this context, lipids (e.g. membrane(More)
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