229 research outputs found
Quality principles for cultural Web sites: a Handbook
No full textprinted and on-line versions, co-author with Eelco Bruinsma, Christophe Dessaux, Ciaran Clissman, Jean-Pierre Dalbéra, David Dawson, Isabelle Dujacquier, Axel Ermert, Pierluigi Feliciati, Fedora Filippi, Muriel Foulonneau,
Antonella Fresa, Monika Hagedorn-Saupe, Annette Kelly, Brian Kelly, Daniel Malbert, Andrea Mulrenin, Stefan Rhode-Enslin, Marius Snyders, Gert Van Tittelboom, Frank von Hage
User-specific effects in Fingerprint Presentation Attacks Detection: Insights for future research
No full textA fingerprint presentation attacks detector (FPAD) is designed to obtain a certain performance regardless of the targeted user population. However, two recent works on facial traits showed that a PAD system can exploit very useful information from the targeted user population. In this paper, we explored the existence of that kind of information in fingerprints when textural features are adopted. We show by experiments that such features embed not only intrinsic differences of the given fingerprint replica with respect to a generic live fingerprint, but also contains characteristics present in other fingers of the same user, and characteristics extracted directly from spoofs of the targeted fingerprint itself. These interesting evidences could lead to novel developments in the design of future FPADs
A classification-selection approach for self updating of face verification systems under stringent storage and computational requirements
No full textNowadays face recognition systems have many application fields. Unfortunately, lighting variations and ageing effects are still open issues. Moreover, face changes over time due to ageing. A further problem is due to occlusions, for example the glass presence. Re-enrolling user’s face is time-consuming and does not solve above problems. Therefore, unsupervised template update has been proposed, and named self update. Basically, this algorithm adapts/modifies templates or face models by collecting samples during system operations. The most effective variant of self update is based on the collection of multiple templates. However, this approach has been evaluated and tested in conditions under which the possible number of collectable templates is uncostrained. Actually, available resources are limited in memory and computational power, thus it is likely that it is not possible to have more than a pre-set number of templates. In this paper, we propose a classification-selection approach, based on the combination of self update and C-means algorithms, which keeps constant the number of templates and improve the ratio between intra-class variations and inter-class variations for each user. Experimental results show the effectiveness of this method with respect to standard self update
On the interoperability of capture devices in fingerprint presentation attacks detection
No full textA presentation attack consists in submitting to the fingerprint capture device an artificial replica of the finger of the targeted client. If the sensor is not equipped with an appropriate algorithm aimed to detect the fingerprint spoof, the system processes the obtained image as a one belonging to a real fingerprint. In order to face this problem, several presentation attacks detection (PAD) algorithms have been proposed so far. Current methods heavily rely on features extracted from a large data set of fake and real fingerprint images, and an appropriate classifier trained with such data to distinguish between live (real) and fake (spoof) fingerprint images. Building such data set requires a significant effort for fabricating samples of fake fingerprints, with the most effective materials used to circumvent the sensor. Interesting and promising results have been obtained, but they also suggest that the PAD is tailored on the particular sensor. Small and significant differences also occur when a novel version of the same sensor is released, and this may affect the PAD. Therefore, making a PAD interoperable is among the main current issues when considering fingerprints as the first level of protection and security of logical or physical resources. This paper is a first attempt to assess at which extent the sensor interoperability can be an issue for fingerprint PADs and to eventually propose a solution to this limitation. In particular, textural features will be under focus and a feature space transformation method based on the least square is proposed
Incremental Support Vector Machine for self-updating Fingerprint Presentation Attack Detection systems
No full textIn this years Fingerprint Presentation Attack Detection (FPAD) had an increasing interest and the performances became acceptable, especially thanks to the LivDet protocols into the International Fingerprint Liveness Detection competition. A security issue arose from LivDet2015: the FPAD systems are not invariant towards the materials for fabricating spoofs. In other words, some previous works pointed out the vulnerability of these systems when an attackers uses unexpected materials. In this paper, we proposed a solution that exploit the self-update abilities of the classifier to adapt itself to never-seen-before attacks over the time. Experimental results on four LivDet data sets showed that the proposed method allowed to manage this vulnerability
On combining edge detection methods for improving BSIF based facial recognition performances
No full textLighting variation is a major challenge for an automatic face recognition system. In order to overcome this problem, many methods have been proposed. Most of them try to extract features invariant to illumination changes or to reduce illumination changes in a pre-processing step and to extract features for recognition. In this paper, we present a procedure similar to the latter where the two steps are complementary. In the pre-processing step we deal with the illumination changes and in the features extraction step we use the BSIF (Binarized Statistical Image Features), a recently proposed textural algorithm. In our opinion, a method capable of reducing the lighting variations is ideal for an algorithm like the BSIF. The performance of our system has been tested on the FRGC dataset and the presented results show the validity of our approach
Erosion de la nature, stratification de l'humain. Tournant ontologique et écologie sémiotique
No full textThe article “Érosion de la nature, stratification de l’humain: Tournant ontologique et écologie sémiotique” by Pierluigi Basso Fossali explores the interplay between ecological thought and semiotics, emphasizing the ontological challenges posed by the relationship between nature and culture. The author critiques the oversimplification of nature as a static regulatory principle, advocating instead for a dynamic semiotic ecology that acknowledges the interdependence of cultures, environments, and symbolic systems. The text highlights the necessity of rethinking environmental discourse through a multi-layered perspective that transcends traditional dichotomies, such as nature versus culture, while embracing the epistemological contributions of diverse civilizations. By integrating the notions of resistance, translation, and intersubjectivity, the article argues for a pluralistic understanding of ecological frameworks as both cultural constructs and practical paradigms for addressing global environmental challenges
Playing with autism. Encountering Simona Concaro by her music. Vol. 1.1
No full textPlaying with Autism contains twenty-four original pieces for piano, recorded and carefully transcribed in current music notation by Pierluigi Politi and Hanna Shybayeva. Simona Concaro, the author, is a young woman suffering of low-functioning autism. She lives in Cascina Rossago, a farm-community, designed to meet the needs of people with autism, in Oltrepo pavese (Italy).
Since she was three, Simona Concaro has created original compositions on piano, instrument she learned by herself, refusing any kind of musical education. In everyday life, Simona does not use verbal language and has low autonomy. Her music, on the contrary, contains interesting features – melodic, rhythmic and harmonic –, even in the presence of some iterative elements, typical of the autistic spectrum
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