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Computationally intensive methods

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Presentation on theme: "Computationally intensive methods"— Presentation transcript:

1 Computationally intensive methods
Ercan E. Kuruoglu CNR – Istituto di Scienza e Tecnologie dell’Informazione Pisa, Italy Muscle Joint WP5-WP7 Focus Meeting, Rocquencourt, December 2005

2 introduction MCMC Particle filtering What we can offer
Overview introduction MCMC Particle filtering What we can offer What we look for

3 Numerical Bayesian Techniques
Bayesian methods frequently involve integrals of Averaging Marginalisation Normalisation which are difficult to evaluate. Therefore numerical integration techniques are adopted.

4 Alternative Statistics
In most applications of statistical signal and image processing classical statistical measures, i.e. second order statistics is used Instead a wide variety of other statistics exists Higher order statistics Fractional lower order statistics Log statistics Extreme value statistics We would like to explore the potentials of log statistics and extreme values statistics in image, video and multimedia problems

5 Markov Chain Monte Carlo
Samples from a pdf with clever Markov Chain moves Economic in terms of samples needed for describing a pdf Analytical difficulties are surpassed

6 Particle Filtering In various real life applications, the signal is non-stationary, and MCMC being a batch processing technique falls short of following non-stationarity Wiener filter Kalman filter linear observations (h) Gaussian observation noise (n) linear state process (f) Gaussian process noise (v)

7 Applications we have worked on
Source separation Speckle filtering in synthetic aperture radar images

8 Astrophysical source separation

9 Original sources : CMB Galactic Syncrotron Galactic Dust
Observed maps: 30 Ghz Ghz Ghz

10 SAR speckle filtering

11 Preliminary results with a special case of Particle filter
Optical image SAR image 5 looks Gamma Filter Particle Filter Gençağa et. al.

12 What we would like to share with partners
Expertise in MCMC and Particle filtering Expertise in extreme value statistics, alpha-stable models (impulsive and nonsymmetric data models Particle filtering code For model selection problems: Reversible Jump MCMC code


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