אירועים
אירועים והרצאות בפקולטה למדעי המחשב ע"ש הנרי ומרילין טאוב
אלברט אכטנברג (הנדסת חשמל, טכניון)
יום שלישי, 29.03.2011, 11:30
חדר 1061, בניין מאייר, הפקולטה להנדסת חשמל
We address the open problem of blindly separating single-path position
varying image mixtures, without having prior information about the
sources. We assume that the mixing system's spatial distortion and
attenuation change with position. A staged method for estimating the
mixing models is used in turn to recover source signals from such
mixtures. Our method is based on a Staged Sprase Component Analysis
(SSCA) of the mixtures. Our method consists of three stages: aligning
the signals to estimate the spatial distortion component of the mixing
system; classifying the sparse signal samples to their estimated sources
and estimating the spatial attenuation component of the mixing system;
and finally inverting the mixing system to recover the sources. Small
error in the spatial distortion component leads to a significant
degradation in separation quality. However, in practice, uncertainty is
associated with the model estimation stage, due to: noisy samples; bad
spatial spread of samples; mixed samples in the sparse representation
and more. We propose a solution by adding a step of model refinement
that is based on simple image quality measures that would allow us to
improve separation results. We test some standard methods and propose a
new aproach based on Phase Congruency measure.
M.Sc. thesis under the supervision of Prof. Zeevi