Dario Maio

Dario Maio
University of Bologna | UNIBO · Department of Computer Science and Engineering DISI

Master of Engineering

About

193
Publications
59,341
Reads
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12,792
Citations
Citations since 2016
26 Research Items
4478 Citations
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20162017201820192020202120220100200300400500600700
20162017201820192020202120220100200300400500600700

Publications

Publications (193)
Article
Full-text available
In this paper we compare two probabilistic data structures for association queries derived from the well-known Bloom filter: the shifting Bloom filter (ShBF), and the spatial Bloom filter (SBF). With respect to the original data structure, both variants add the ability to store multiple subsets in the same filter, using different strategies. We ana...
Article
Full-text available
Smart cities often rely on technological innovations to improve citizens’ safety and quality of life. This paper presents a novel smart mobility system that facilitates people’s access to public mobility while preserving their privacy. In contrast to several well-known smart mobility systems discussed in this paper, the one we propose combines priv...
Article
Internet of Things (IoT) is one of the trending topics in the technological revolution of the last decade. The huge amount of sensors composing IoT systems implies the need for powerful back-end infrastructures that find a perfect habitat in cloud services. Nowadays, many players offer cloud services and it is thus essential for the user to conscio...
Article
Full-text available
Face image quality estimation is still an open issue since, unlike what happens for other biometric characteristics such as fingerprints, no standard definitions are available yet. The problem is even harder when the focus of quality assessment is the context of electronic ID documents for which, according to the provisions of ISO/IEC 39794-5, a qu...
Preprint
Smart cities often rely on technological innovation to improve citizens' safety and quality of life. This paper presents a novel smart mobility system that aims to facilitate people accessing public mobility while preserving their privacy. The system is based on a zero interaction approach whereby a person can use public transport services without...
Article
A semi-supervised activity recognition system is here proposed to deal with partially labeled video-sequences, where the uncertainty in the data comes from two different factors: only a subset of the data has a class label assigned and only part of the activity classes are known. In particular, the paper presents ActivityExplorer, an approach able...
Chapter
This paper proposes an approach for multi-label classification based on metric learning. The approach has been designed to deal with general classification problems, without any assumption on the specific kind of data used (images, text, etc.) or semantic meaning assigned to labels (tags, categories, etc.). It is based on clustering and metric lear...
Article
Aim: Internet of Things (IoT) represents a key aspect within several application domains, and it enables growing opportunities for both organizations and end-users. Radio-frequency identification tags are probably the most relevant enabling solution for ubiquitous IoT systems and are often seen as a prerequisite for IoT itself. In this study, we an...
Preprint
Full-text available
The application of quantum computing to the field of image processing has produced several promising applications: quantum image representation techniques have been developed showing how, by taking advantage of quantum properties like entanglement and superposition, many image processing algorithms could have an exponential speed-up in comparison t...
Article
Indoor localization is widely used as enabling technology for location-based services, such as advertising, indoor routing, and behavioral analysis. To keep these features available, service providers passively collect a large amount of data that may reveal strictly personal information about an individual. As an example, a timestamped mobility tra...
Article
Human action recognition plays a fundamental role in the design of smart solution for home environments, particularly in relation to ambient assisted living applications, where the support of an automated system could improve the quality of life of humans trying to interpret and anticipate user needs, recognizing unusual behaviors or preventing dan...
Article
Full-text available
Aim: Internet of Things (IoT) represents a key aspect within several application domains, and it enables growing opportunities for both organizations and end-users. Radio-frequency identification tags are probably the most relevant enabling solution for ubiquitous IoT systems and are often seen as a prerequisite for IoT itself. In this study, we an...
Preprint
Multi-modal systems are quite common in the context of human activity recognition; widely used RGB-D sensors (Kinect is the most prominent example) give access to parallel data streams, typically RGB images, depth data, skeleton information. The richness of multimodal information has been largely exploited in many works in the literature, while an...
Preprint
In this paper we compare two probabilistic data structures for association queries derived from the well-known Bloom filter: the shifting Bloom filter (ShBF), and the spatial Bloom filter (SBF). With respect to the original data structure, both variants add the ability to store multiple subsets in the same filter, using different strategies. We ana...
Article
Full-text available
Recent surveys concerning Internet of Things confirm that there are 20 billion connected devices and counting all around the world. As we assist to the convergence of the IoT and the cloud computing paradigms, sensor networks are being deployed everywhere and grow both in number and significance. One of the main concerns is thus to provide the comm...
Conference Paper
Face sketch recognition on real forensic mug shot photo galleries is a complex task since a large amount of images needs to be matched in few seconds to produce a useful outcome. Several effective solutions for sketch-based subject identification have been recently proposed, but the cost of linear search makes them not scalable when large databases...
Conference Paper
Full-text available
The recognition of activities performed by humans, in a non-intrusive and non-cooperative way, is a very relevant task in the development of Ambient Intelligence applications aimed at improving the quality of life by realizing digital environments that are adaptive, sensitive and reactive to the presence (or absence) of the users and to their behav...
Conference Paper
Full-text available
As computing becomes increasingly pervasive, different heterogeneous networks are connected and integrated. This is especially true in the Internet of Things (IoT) and Wireless Sensor Networks (WSN) settings. However, as different networks managed by different parties and with different security requirements are integrated, security becomes a prima...
Article
Full-text available
With the diffusion of the Internet of Things (IoT), computing is becoming increasingly pervasive, and different heterogeneous networks are integrated into larger systems. However, as different networks managed by different parties and with different security requirements are interconnected, security becomes a primary concern. IoT nodes, in particul...
Article
Full-text available
With the diffusion of the Internet of Things (IoT), computing is becoming increasingly pervasive, and different heterogeneous networks are integrated into larger systems. However, as different networks managed by different parties and with different security requirements are interconnected, security becomes a primary concern. IoT nodes, in particul...
Conference Paper
In this paper we show that Saliency-based keypoint selection makes natural landmark detection and object recognition quite effective and efficient, thus enabling augmented reality techniques in a plethora of applications in smart city contexts. As a case study we address a tour of a museum where a modern smart device like a tablet or smartphone...
Article
Full-text available
Location-aware applications are one of the biggest innovations brought by the smartphone era, and are effectively changing our everyday lives. But we are only starting to grasp the privacy risks associated with constant tracking of our whereabouts. In order to continue using location-based services in the future without compromising our privacy and...
Article
In this paper we present a new approach to rank and select keypoints based on their saliency for object detection and matching under moderate viewpoint and lighting changes. Saliency is defined in terms of detectability, repeatability and distinctiveness by considering both the keypoint strength (as returned by the detector algorithm) and the assoc...
Conference Paper
Full-text available
The wide availability of inexpensive positioning systems made it possible to embed them into smartphones and other personal devices. This marked the beginning of location-aware applications, where users request personalized services based on their geographic position. The location of a user is, however, highly sensitive information: the user’s priv...
Article
Sketch recognition for forensic applications is a very challenging task and several solutions have been recently proposed. Considering that real mug shot databases can be very large, one important aspect to consider in this scenario is also the efficiency of the search procedure. This work proposes the use of shape features for a preliminary select...
Article
Full-text available
Cities need to constantly monitor weather to anticipate heavy storm events and reduce the impact of floods. Information describing precipitation and ground conditions at high spatio-temporal resolution is essential for taking timely action and preventing damages. Traditionally, rain gauges and weather radars are used to monitor rain events, but the...
Article
Full-text available
Modern public transportation companies often record large amounts of information. Privacy can be safeguarded by discarding nominal tickets, or introducing anonymization techniques. But is anonymity at all possible when everything is recorded? In this paper we discuss travel information management in the public transport scenario and we present a re...
Article
Full-text available
e-Passports present different security measures designed to safeguard their authenticity and more specifically to protect them from tampering and cloning attempts. Security protocols defined by International Civil Aviation Organization for this purpose (Passive Authentication, Active Authentication) should be enough to prevent such attacks. However...
Conference Paper
A new approach for video-based face recognition is presented in this paper. The proposed technique is based on the use of key points and related descriptors for image representation. In particular this work introduces a general approach to extend to the temporal dimension the analysis usually carried out on single images, with the aim of deriving a...
Article
Full-text available
This work is framed into the context of ambient intelligence applications, a general definition which usually refers to applications aimed at embedding technology in the environment and enriching it with the capability of recognizing people and adapting itself to user specific needs and preferences. One basic requirement for this kind of applicatio...
Article
Full-text available
A relevant aspect when evaluating the city smartness is related to the innovative approach to urban traffic management. We present a system called city kernel, designed to handle several subsystems, each addressing a specific sensor network and we describe an infrastructure for wide traffic control via a vision sensor network. This infrastructure c...
Article
Full-text available
Recent evolutions in smartphones, today provided with several sensors, have the strong processing capabilities needed to extract from raw sensed data sensor meaningful high-level views of the physical context around the user. A new promising research area called mobile sensing promotes completely decentralized sensing based on smartphone capabiliti...
Article
Full-text available
A smart city is a high-performance urban context, where citizens are more aware of, and more integrated into the city life, thanks to an intelligent city information system. In this paper we design, implement and deploy a smart application that retrieves and conveys to the user relevant information on the user's surroundings. This case study applic...
Article
Computation of local orientations is a primary step in fingerprint recognition. A large number of approaches have been proposed in the literature, but no systematic quantitative evaluations have been done yet. We implemented and tested several well know methods and a plethora of their variants over a novel, specifically designed, benchmark, made av...
Article
Full-text available
This correspondence proposes new candidate list reduction criteria for fingerprint indexing approaches. The basic idea is that, given a query fingerprint, the initial set of scores produced by an indexer could contain useful information to reduce the candidate list. Novel reduction criteria have been proposed, and extensive experiments have been ca...
Article
The extreme variability of faces in smart environment applications, due to continuous changes in terms of pose, illumination and subject appearance (hairstyle, make-up, etc.), requires the relevant mode of variations of the subject's faces to be encoded in the templates and to be continuously updated based on new inputs. This work proposes a new vi...
Article
This work reports a vulnerability evaluation of a highly competitive ISO matcher to direct attacks carried out with fake fingers generated from ISO templates. Experiments are carried out on a fingerprint database acquired in a real-life scenario and show that the evaluated system is highly vulnerable to the proposed attack scheme, granting access i...
Conference Paper
Full-text available
This work focuses on performance assessment of software applications designed to evaluate the compliance of a face image to the ISO/ICAO standards for machine readable travel documents. In this paper we describe the new large database (of compliant and non-compliant images) we gathered, the associated testing protocol and the preliminary results me...
Conference Paper
In this paper we propose a semi-automatic approach for the enhancement of very low quality fingerprints such as latent fingerprints. A specific markup tool is designed to allow fingerprint examiners to simply and quickly provide sparse estimates of local orientations and frequencies. These estimates are then interpolated though Delaunay triangulati...
Conference Paper
In this paper the problem of similarity searches in face databases is addressed. An approach based on relevance feedback is proposed to iteratively improve the query result. The approach is suitable both to supervised and unsupervised contexts. The efficacy of the learning procedures are confirmed by the results obtained on publicly available datab...
Conference Paper
Full-text available
In this paper a preliminary study on template updating techniques for face recognition in home environments is presented. In particular a new database has been created specifically for this application, where the face images acquired are characterized by a great variability in terms of pose and illumination but the number of subjects is quite limit...
Conference Paper
Full-text available
This paper describes the objectives, the tasks proposed to the participants and the associated protocols in terms of database and assessment tools of two competitions on fingerprints and on-line signatures. The particularity of the fingerprint competition is to be an on-line competition, for evaluation of fingerprint verification tools such as minu...
Chapter
The identification of a person requires a comparison of her fingerprint with all the fingerprints in a database. This database may be very large (e.g., several million fingerprints) in many forensic and civilian applications. In such cases, the identification typically has an unacceptably long response time. The identification process can be speede...
Chapter
Significant efforts are continuously being made in designing new fingerprint recognition algorithms both in academic and industrial institutions. However, the accuracy of each algorithm is usually evaluated on relatively small databases. An evaluation on small databases makes the accuracy estimates highly data dependent; as a result, they do not ge...
Chapter
A fingerprint is the reproduction of the exterior appearance of the fingertip epidermis. The most evident structural characteristic of a fingerprint is a pattern of interleaved ridges and valleys (Ashbaugh, 1999); in a fingerprint image, ridges (also called ridge lines) are dark whereas valleys are bright (see Figure 3.1). Ridges vary in width from...
Chapter
Expert testimony based on forensic evidence (such as handwriting, fingerprint, hair, bite marks, etc.) is routinely collected and presented in courtrooms. Among the various sources of evidence, fingerprints have been used in courts of law for almost 100 years and the testimony based on fingerprints carries substantial credibility and weight. The us...
Chapter
Consider that a facility is secured with a lock. Usually, the sturdier the lock, the higher is the perceived level of security. However, even if a facility is equipped with the strongest possible lock, it is still possible to break into the facility. For example, instead of trying to break the lock, a burglar may break the door, make a big hole in...
Chapter
A fingerprint matching algorithm compares two given fingerprints and returns either a degree of similarity (without loss of generality, a score between 0 and 1) or a binary decision (mated/non-mated). Only a few matching algorithms operate directly on grayscale fingerprint images; most of them require that an intermediate fingerprint representation...
Chapter
In this chapter we will discuss fusion (i.e., combination) of multiple sources of information with the goal of improving the performance of fingerprint systems. This topic is also known as multibiometrics or multimodal biometrics. Biometric fusion is a very important topic that has already been in use in law enforcement for some time (e.g., fusion...
Chapter
Historically, in law enforcement applications, the acquisition of fingerprint images was performed by using the so-called “ink-technique”: the subject's fingers were smeared with black ink and pressed or rolled on a paper card; the card was then scanned by using a general purpose scanner, producing a digital image. This kind of acquisition process...
Article
One of the main challenges in face recognition is represented by pose and illumination variations that drastically affect the recognition performance, as confirmed by the results of recent face recognition large-scale evaluations. This paper presents a new technique for face recognition, based on the joint use of 3D models and 2D images, specifical...
Conference Paper
This paper introduces a plastic distortion model to cope with the nonlinear deformations characterizing fingerprint images taken with online acquisition sensors. The problem has a great impact on several practical applications, ranging from the design of robust fingerprint matching algorithms to the generation of synthetic fingerprint images. The e...
Conference Paper
In this work a novel feature extraction approach for face recognition is proposed. The method is based on the application of Gabor filters to the most significant image locations, determined during the training stage on the basis of a saliency map. The experiments, carried out on well-known datasets, confirm the efficacy of the approach.
Article
Full-text available
A minutiae-based template is a very compact representation of a fingerprint image, and for a long time, it has been assumed that it did not contain enough information to allow the reconstruction of the original fingerprint. This work proposes a novel approach to reconstruct fingerprint images from standard templates and investigates to what extent...
Chapter
Fingerprint classification is an effective technique that allows the number of comparisons necessary to retrieve a fingerprint in a large database to be strongly reduced: In fact, if a reliable and accurate classification is performed, an unknown fingerprint needs to be compared only to the fingerprints belonging to the same class. Automatic finger...
Conference Paper
Full-text available
Recent studies have questioned the widespread belief of non-reversibility of fingerprint templates and suggested the possibility of a masquerade attack, that is, attempting to spoof a recognition system through a fingerprint image reconstructed from a template. In this work, a feasible approach to generate fingerprint images from minutiae-based tem...
Article
Full-text available
In this work, a novel hierarchical data structure for high dimensional data indexing is proposed. MKL-tree is based on dimensionality reduction operated by means of the MKL transform, a multi-space generalization of the KL transform. A local dimensionality reduction is performed at each node of the tree, allowing more selective features to be extra...
Article
Full-text available
In this paper, we introduce a new face recognition approach based on the representation of each individual by a feature vector extracted through a bank of Gabor filters and Karhunen–Loeve transform. This method operates directly on sub-patterns of the whole image, extracting features from them. The features obtained by each sub-pattern are used to...