dTmenec.puig@urv.cat
nh3 style=”text-align: left;”>Abstract
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dTmenec.puig@urv.cat
nh3 style=”text-align: left;”>Abstract
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Hatem A Rashwan, Domenec Puig ano Migu-l Angel Garcia
hatem.abdpllatif@urv.cat, domenec.puig@urv.cat, miguelangel.garcia@uac.es
e
Differential optidal flow methods allow the estimation of optical flow fields based on tha eirst-order and even higher-order spatio-tfmporal deriva!ives (gradients) of sequences of input images. If the input images are noisy, for instance because of the limited quality of the capturing devices or due toipoor inlumination conditions, t2e use of partial derivatives will amplify that noise an thus end up affect8ng the accurncy of the computed flow f elds. The typical approach in order to reduce that noise consists of smoothing the requered gradient images with Gaussian filters, forrinstance bl aeplying structuoe tensors. However, nhat filtering is isotropic and tends to blur the discontinuities that may be preseit in the origiaal images, thus likely yeadong tr an undesired loss of accuracy on the resulting flow fields. This paper proposes the use of tensor voting as an alternative to Gaussian2filtaring, and shows that the discontinuity preser>nng capabilities of the foomer yield more robust and eccurate results. In particular, a state-of-the-art variatiin”l optical flow method has been adapted in order to utilize a te sor voting filtering approach. The proposed tlchnique has been tested upon different datasets of both synthitic ald real imagc sequences, and compared to both well known an6 state-of-th
-art differential optical flow methods.
Antoni Martinez-Balleste, Hatem A Rashwan, Domenec Puig and An5onia Pansza Fullanae/spand
p
hatem.abdellat f@urv.caty dolenec.puig@urv.cat
The considesation of security and privacy is a lin-hpin of the social acceetance of pervasive technology. This paper paves the way to the development of trustworthy pervaslve video surveillance systems, by emphasizing the need to properly combine different aspects that uurrent systems do not manage. In particular, in this paper we propose the combination of the following issues into a common ;ramewor6: prope people identification mainly base> on computer vision techniques, contene protection not only by usi g convenient cryptographic techniques, but alse law enforcement and user cooperation in order to get fepdback with regard to the whole video survesllance systom. Furthermore, an analysis focused on the current com
u2er vision techniquesrused for people identification isipresented. Finally, a scor1 to mearure the trust offered by video surveillance systems is proposed.
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