6 research outputs found
Phase retrieval with a multivariate Von Mises prior: from a Bayesian formulation to a lifting solution
In this paper, we investigate a new method for phase recovery when prior
information on the missing phases is available. In particular, we propose to
take into account this information in a generic fashion by means of a
multivariate Von Mises dis- tribution. Building on a Bayesian formulation (a
Maximum A Posteriori estimation), we show that the problem can be expressed
using a Mahalanobis distance and be solved by a lifting optimization procedure.Comment: Preprint of the paper published in the proc. of ICASSP'1
Reference-less measurement of the transmission matrix of a highly scattering material using a DMD and phase retrieval techniques
This paper investigates experimental means of measuring the transmission
matrix (TM) of a highly scattering medium, with the simplest optical setup.
Spatial light modulation is performed by a digital micromirror device (DMD),
allowing high rates and high pixel counts but only binary amplitude modulation.
We used intensity measurement only, thus avoiding the need for a reference
beam. Therefore, the phase of the TM has to be estimated through signal
processing techniques of phase retrieval. Here, we compare four different phase
retrieval principles on noisy experimental data. We validate our estimations of
the TM on three criteria : quality of prediction, distribution of singular
values, and quality of focusing. Results indicate that Bayesian phase retrieval
algorithms with variational approaches provide a good tradeoff between the
computational complexity and the precision of the estimates
Spatial intra-prediction based on mixtures of sparse representations
Abstract-In this paper, we consider the problem of spatial prediction based on sparse representations. Several algorithms dealing with this problem can be found in the literature. We propose a novel method involving a mixture of sparse representations. We first place this approach into a probabilistic framework and then derive a practical procedure to solve it. Comparisons of the rate-distortion performance show the superiority of the proposed algorithm with regard to other stateof-the-art algorithms
Probabilistic dance performance alignment by fusion of multimodal features
International audienc
AN ADVANCED VIRTUAL DANCE PERFORMANCE EVALUATOR
International audienc