53,151 research outputs found
Info-Greedy sequential adaptive compressed sensing
We present an information-theoretic framework for sequential adaptive
compressed sensing, Info-Greedy Sensing, where measurements are chosen to
maximize the extracted information conditioned on the previous measurements. We
show that the widely used bisection approach is Info-Greedy for a family of
-sparse signals by connecting compressed sensing and blackbox complexity of
sequential query algorithms, and present Info-Greedy algorithms for Gaussian
and Gaussian Mixture Model (GMM) signals, as well as ways to design sparse
Info-Greedy measurements. Numerical examples demonstrate the good performance
of the proposed algorithms using simulated and real data: Info-Greedy Sensing
shows significant improvement over random projection for signals with sparse
and low-rank covariance matrices, and adaptivity brings robustness when there
is a mismatch between the assumed and the true distributions.Comment: Preliminary results presented at Allerton Conference 2014. To appear
in IEEE Journal Selected Topics on Signal Processin
Model for Estimation of Bounds in Digital Coding of Seabed Images
This paper proposes the novel model for estimation of bounds in digital coding of images. Entropy coding of images is exploited to measure the useful information content of the data. The bit rate achieved by reversible compression using the rate-distortion theory approach takes into account the contribution of the observation noise and the intrinsic information of hypothetical noise-free image. Assuming the Laplacian probability density function of the quantizer input signal, SQNR gains are calculated for image predictive coding system with non-adaptive quantizer for white and correlated noise, respectively. The proposed model is evaluated on seabed images. However, model presented in this paper can be applied to any signal with Laplacian distribution
Quantum reading under a local energy constraint
Nonclassical states of light play a central role in many quantum information
protocols. Their quantum features have been exploited to improve the readout of
information from digital memories, modelled as arrays of microscopic beam
splitters [S. Pirandola, Phys. Rev. Lett. 106, 090504 (2011)]. In this model of
quantum reading, a nonclassical source of light with Einstein-Podolski-Rosen
correlations has been proven to retrieve more information than any classical
source. In particular, the quantum-classical comparison has been performed
under a global energy constraint, i.e., by fixing the mean total number of
photons irradiated over each memory cell. In this paper we provide an
alternative analysis which is based on a local energy constraint, meaning that
we fix the mean number of photons per signal mode irradiated over the memory
cell. Under this assumption, we investigate the critical number of signal modes
after which a nonclassical source of light is able to beat any classical source
irradiating the same number of signals.Comment: REVTeX. Published versio
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