2023
Conference article
Open Access
SegmentCodeList: unsupervised representation learning for human skeleton data retrieval
Sedmidubsky J., Carrara F., Amato G.
Recent progress in pose-estimation methods enables the extraction of sufficiently-precise 3D human skeleton data from ordinary videos, which offers great opportunities for a wide range of applications. However, such spatio-temporal data are typically extracted in the form of a continuous skeleton sequence without any information about semantic segmentation or annotation. To make the extracted data reusable for further processing, there is a need to access them based on their content. In this paper, we introduce a universal retrieval approach that compares any two skeleton sequences based on temporal order and similarities of their underlying segments. The similarity of segments is determined by their content-preserving low-dimensional code representation that is learned using the Variational AutoEncoder principle in an unsupervised way. The quality of the proposed representation is validated in retrieval and classification scenarios; our proposal outperforms the state-of-the-art approaches in effectiveness and reaches speed-ups up to 64x on common skeleton sequence datasets.Source: ECIR 2023 - 45th European Conference on Information Retrieval, pp. 110–124, Dublin, Ireland, 2-6/4/2023
DOI: 10.1007/978-3-031-28238-6_8
Project(s): AI4Media
Metrics:
Sedmidubsky J., Carrara F., Amato G.
Recent progress in pose-estimation methods enables the extraction of sufficiently-precise 3D human skeleton data from ordinary videos, which offers great opportunities for a wide range of applications. However, such spatio-temporal data are typically extracted in the form of a continuous skeleton sequence without any information about semantic segmentation or annotation. To make the extracted data reusable for further processing, there is a need to access them based on their content. In this paper, we introduce a universal retrieval approach that compares any two skeleton sequences based on temporal order and similarities of their underlying segments. The similarity of segments is determined by their content-preserving low-dimensional code representation that is learned using the Variational AutoEncoder principle in an unsupervised way. The quality of the proposed representation is validated in retrieval and classification scenarios; our proposal outperforms the state-of-the-art approaches in effectiveness and reaches speed-ups up to 64x on common skeleton sequence datasets.Source: ECIR 2023 - 45th European Conference on Information Retrieval, pp. 110–124, Dublin, Ireland, 2-6/4/2023
DOI: 10.1007/978-3-031-28238-6_8
Project(s): AI4Media
Metrics:
See at:
ISTI Repository 
| link.springer.com 
| CNR ExploRA
2023
Conference article
Open Access
Social and hUman ceNtered XR
Vairo C., Callieri M., Carrara F., Cignoni P., Di Benedetto M., Gennaro C., Giorgi D., Palma G., Vadicamo L., Amato G.
The Social and hUman ceNtered XR (SUN) project is focused on developing eXtended Reality (XR) solutions that integrate the physical and virtual world in a way that is convincing from a human and social perspective. In this paper, we outline the limitations that the SUN project aims to overcome, including the lack of scalable and cost-effective solutions for developing XR applications, limited solutions for mixing the virtual and physical environment, and barriers related to resource limitations of end-user devices. We also propose solutions to these limitations, including using artificial intelligence, computer vision, and sensor analysis to incrementally learn the visual and physical properties of real objects and generate convincing digital twins in the virtual environment. Additionally, the SUN project aims to provide wearable sensors and haptic interfaces to enhance natural interaction with the virtual environment and advanced solutions for user interaction. Finally, we describe three real-life scenarios in which we aim to demonstrate the proposed solutions.Source: Ital-IA 2023 - Workshop su AI per l'industria, Pisa, Italy, 29-31/05/2023
Vairo C., Callieri M., Carrara F., Cignoni P., Di Benedetto M., Gennaro C., Giorgi D., Palma G., Vadicamo L., Amato G.
The Social and hUman ceNtered XR (SUN) project is focused on developing eXtended Reality (XR) solutions that integrate the physical and virtual world in a way that is convincing from a human and social perspective. In this paper, we outline the limitations that the SUN project aims to overcome, including the lack of scalable and cost-effective solutions for developing XR applications, limited solutions for mixing the virtual and physical environment, and barriers related to resource limitations of end-user devices. We also propose solutions to these limitations, including using artificial intelligence, computer vision, and sensor analysis to incrementally learn the visual and physical properties of real objects and generate convincing digital twins in the virtual environment. Additionally, the SUN project aims to provide wearable sensors and haptic interfaces to enhance natural interaction with the virtual environment and advanced solutions for user interaction. Finally, we describe three real-life scenarios in which we aim to demonstrate the proposed solutions.Source: Ital-IA 2023 - Workshop su AI per l'industria, Pisa, Italy, 29-31/05/2023
See at:
ISTI Repository | CNR ExploRA
2023
Report
Restricted
SUN D1.1 - Management Website
Amato G., Bolettieri P., Gennaro C., Vadicamo L., Vairo C.
Report describing the online web accessible repository for all project-related documentation, which serves as the primary means for project partners to manage and share documents of the project. https://wiki.sun-xr-project.euSource: ISTI Project Report, SUN, D1.1, 2023
Amato G., Bolettieri P., Gennaro C., Vadicamo L., Vairo C.
Report describing the online web accessible repository for all project-related documentation, which serves as the primary means for project partners to manage and share documents of the project. https://wiki.sun-xr-project.euSource: ISTI Project Report, SUN, D1.1, 2023
See at:
CNR ExploRA
2023
Conference article
Open Access
Unsupervised domain adaptation for video violence detection in the wild
Ciampi L., Santiago C., Costeira J. P., Falchi F. Gennaro C., Amato G.
Video violence detection is a subset of human action recognition aiming to detect violent behaviors in trimmed video clips. Current Computer Vision solutions based on Deep Learning approaches provide astonishing results. However, their success relies on large collections of labeled datasets for supervised learning to guarantee that they generalize well to diverse testing scenarios. Although plentiful annotated data may be available for some pre-specified domains, manual annotation is unfeasible for every ad-hoc target domain or task. As a result, in many real-world applications, there is a domain shift between the distributions of the train (source) and test (target) domains, causing a significant drop in performance at inference time. To tackle this problem, we propose an Unsupervised Domain Adaptation scheme for video violence detection based on single image classification that mitigates the domain gap between the two domains. We conduct experiments considering as the source labeled domain some datasets containing violent/non-violent clips in general contexts and, as the target domain, a collection of videos specific for detecting violent actions in public transport, showing that our proposed solution can improve the performance of the considered models.Source: IMPROVE 2023 - 3rd International Conference on Image Processing and Vision Engineering, pp. 37–46, Prague, Czech Republic, 21-23/04/2023
DOI: 10.5220/0011965300003497
Project(s): AI4Media
Metrics:
Ciampi L., Santiago C., Costeira J. P., Falchi F. Gennaro C., Amato G.
Video violence detection is a subset of human action recognition aiming to detect violent behaviors in trimmed video clips. Current Computer Vision solutions based on Deep Learning approaches provide astonishing results. However, their success relies on large collections of labeled datasets for supervised learning to guarantee that they generalize well to diverse testing scenarios. Although plentiful annotated data may be available for some pre-specified domains, manual annotation is unfeasible for every ad-hoc target domain or task. As a result, in many real-world applications, there is a domain shift between the distributions of the train (source) and test (target) domains, causing a significant drop in performance at inference time. To tackle this problem, we propose an Unsupervised Domain Adaptation scheme for video violence detection based on single image classification that mitigates the domain gap between the two domains. We conduct experiments considering as the source labeled domain some datasets containing violent/non-violent clips in general contexts and, as the target domain, a collection of videos specific for detecting violent actions in public transport, showing that our proposed solution can improve the performance of the considered models.Source: IMPROVE 2023 - 3rd International Conference on Image Processing and Vision Engineering, pp. 37–46, Prague, Czech Republic, 21-23/04/2023
DOI: 10.5220/0011965300003497
Project(s): AI4Media
Metrics:
See at:
ISTI Repository | CNR ExploRA | www.scitepress.org
2022
Journal article
Open Access
Comparing the performance of Hebbian against backpropagation learning using convolutional neural networks
Lagani G., Falchi F., Gennaro C., Amato G.
In this paper, we investigate Hebbian learning strategies applied to Convolutional Neural Network (CNN) training. We consider two unsupervised learning approaches, Hebbian Winner-Takes-All (HWTA), and Hebbian Principal Component Analysis (HPCA). The Hebbian learning rules are used to train the layers of a CNN in order to extract features that are then used for classification, without requiring backpropagation (backprop). Experimental comparisons are made with state-of-the-art unsupervised (but backprop-based) Variational Auto-Encoder (VAE) training. For completeness,we consider two supervised Hebbian learning variants (Supervised Hebbian Classifiers--SHC, and Contrastive Hebbian Learning--CHL), for training the final classification layer, which are compared to Stochastic Gradient Descent training. We also investigate hybrid learning methodologies, where some network layers are trained following the Hebbian approach, and others are trained by backprop. We tested our approaches on MNIST, CIFAR10, and CIFAR100 datasets. Our results suggest that Hebbian learning is generally suitable for training early feature extraction layers, or to retrain higher network layers in fewer training epochs than backprop. Moreover, our experiments show that Hebbian learning outperforms VAE training, with HPCA performing generally better than HWTA.Source: Neural computing & applications (Print) (2022). doi:10.1007/s00521-021-06701-4
DOI: 10.1007/s00521-021-06701-4
Project(s): AI4EU, AI4Media
Metrics:
Lagani G., Falchi F., Gennaro C., Amato G.
In this paper, we investigate Hebbian learning strategies applied to Convolutional Neural Network (CNN) training. We consider two unsupervised learning approaches, Hebbian Winner-Takes-All (HWTA), and Hebbian Principal Component Analysis (HPCA). The Hebbian learning rules are used to train the layers of a CNN in order to extract features that are then used for classification, without requiring backpropagation (backprop). Experimental comparisons are made with state-of-the-art unsupervised (but backprop-based) Variational Auto-Encoder (VAE) training. For completeness,we consider two supervised Hebbian learning variants (Supervised Hebbian Classifiers--SHC, and Contrastive Hebbian Learning--CHL), for training the final classification layer, which are compared to Stochastic Gradient Descent training. We also investigate hybrid learning methodologies, where some network layers are trained following the Hebbian approach, and others are trained by backprop. We tested our approaches on MNIST, CIFAR10, and CIFAR100 datasets. Our results suggest that Hebbian learning is generally suitable for training early feature extraction layers, or to retrain higher network layers in fewer training epochs than backprop. Moreover, our experiments show that Hebbian learning outperforms VAE training, with HPCA performing generally better than HWTA.Source: Neural computing & applications (Print) (2022). doi:10.1007/s00521-021-06701-4
DOI: 10.1007/s00521-021-06701-4
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | link.springer.com | CNR ExploRA
2022
Conference article
Open Access
AIMH Lab for Trustworthy AI
Messina N., Carrara F., Coccomini D., Falchi F., Gennaro C., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Trustworthy AI. Artificial Intelligence is becoming more and more pervasive in our society, controlling recommendation systems in social platforms as well as safety-critical systems like autonomous vehicles. In order to be safe and trustworthy, these systems require to be easily interpretable and transparent. On the other hand, it is important to spot fake examples forged by malicious AI generative models to fool humans (through fake news or deep-fakes) or other AI systems (through adversarial examples). This is required to enforce an ethical use of these powerful new technologies. Driven by these concerns, this paper presents three crucial research directions contributing to the study and the development of techniques for reliable, resilient, and explainable deep learning methods. Namely, we report the laboratory activities on the detection of adversarial examples, the use of attentive models as a way towards explainable deep learning, and the detection of deepfakes in social platforms.Source: Ital-IA 2020 - Workshop su AI Responsabile ed Affidabile, Online conference, 10/02/2022
Messina N., Carrara F., Coccomini D., Falchi F., Gennaro C., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Trustworthy AI. Artificial Intelligence is becoming more and more pervasive in our society, controlling recommendation systems in social platforms as well as safety-critical systems like autonomous vehicles. In order to be safe and trustworthy, these systems require to be easily interpretable and transparent. On the other hand, it is important to spot fake examples forged by malicious AI generative models to fool humans (through fake news or deep-fakes) or other AI systems (through adversarial examples). This is required to enforce an ethical use of these powerful new technologies. Driven by these concerns, this paper presents three crucial research directions contributing to the study and the development of techniques for reliable, resilient, and explainable deep learning methods. Namely, we report the laboratory activities on the detection of adversarial examples, the use of attentive models as a way towards explainable deep learning, and the detection of deepfakes in social platforms.Source: Ital-IA 2020 - Workshop su AI Responsabile ed Affidabile, Online conference, 10/02/2022
See at:
ISTI Repository | CNR ExploRA | www.ital-ia2022.it
2022
Conference article
Open Access
AIMH Lab for Cybersecurity
Vairo C., Coccomini D. A., Falchi F., Gennaro C., Massoli F. V., Messina N., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Cy-bersecurity. We discuss about our active research fields, their applications and challenges. We focus on face recognition and detection of adversarial examples and deep fakes. We also present our activities on the detection of persuasion techniques combining image and text analysis.Source: Ital-IA 2022 - Workshop su AI per Cybersecurity, 10/02/2022
Vairo C., Coccomini D. A., Falchi F., Gennaro C., Massoli F. V., Messina N., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Cy-bersecurity. We discuss about our active research fields, their applications and challenges. We focus on face recognition and detection of adversarial examples and deep fakes. We also present our activities on the detection of persuasion techniques combining image and text analysis.Source: Ital-IA 2022 - Workshop su AI per Cybersecurity, 10/02/2022
See at:
ISTI Repository | CNR ExploRA | www.ital-ia2022.it
2022
Conference article
Open Access
AIMH Lab for Healthcare and Wellbeing
Di Benedetto M., Carrara F., Ciampi L., Falchi F., Gennaro C., Amato G.
In this work we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Healthcare and Wellbeing. By exploiting the advances of recent machine learning methods and the compute power of desktop and mobile platforms, we will show how artificial intelligence tools can be used to improve healthcare systems in various parts of disease treatment. In particular we will see how deep neural networks can assist doctors from diagnosis (e.g., cell counting, pupil and brain analysis) to communication to patients with Augmented Reality .Source: Ital-IA 2022 - Workshop AI per la Medicina e la Salute, Online conference, 10/02/2022
Di Benedetto M., Carrara F., Ciampi L., Falchi F., Gennaro C., Amato G.
In this work we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Healthcare and Wellbeing. By exploiting the advances of recent machine learning methods and the compute power of desktop and mobile platforms, we will show how artificial intelligence tools can be used to improve healthcare systems in various parts of disease treatment. In particular we will see how deep neural networks can assist doctors from diagnosis (e.g., cell counting, pupil and brain analysis) to communication to patients with Augmented Reality .Source: Ital-IA 2022 - Workshop AI per la Medicina e la Salute, Online conference, 10/02/2022
See at:
ISTI Repository | CNR ExploRA | www.ital-ia2022.it
2022
Conference article
Open Access
AIMH Lab for the Industry
Carrara F., Ciampi L., Di Benedetto M., Falchi F., Gennaro C., Massoli F. V., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Industry. The massive digitalization affecting all the stages of product design, production, and control calls for data-driven algorithms helping in the coordination of humans, machines, and digital resources in Industry 4.0. In this context, we developed AI-based Computer-Vision technologies of general interest in the emergent digital paradigm of the fourth industrial revolution, fo-cusing on anomaly detection and object counting for computer-assisted testing and quality control. Moreover, in the automotive sector, we explore the use of virtual worlds to develop AI systems in otherwise practically unfeasible scenarios, showing an application for accident avoidance in self-driving car AI agents.Source: Ital-IA 2022 - Workshop su AI per l'Industria, Online conference, 10/02/2022
Carrara F., Ciampi L., Di Benedetto M., Falchi F., Gennaro C., Massoli F. V., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Industry. The massive digitalization affecting all the stages of product design, production, and control calls for data-driven algorithms helping in the coordination of humans, machines, and digital resources in Industry 4.0. In this context, we developed AI-based Computer-Vision technologies of general interest in the emergent digital paradigm of the fourth industrial revolution, fo-cusing on anomaly detection and object counting for computer-assisted testing and quality control. Moreover, in the automotive sector, we explore the use of virtual worlds to develop AI systems in otherwise practically unfeasible scenarios, showing an application for accident avoidance in self-driving car AI agents.Source: Ital-IA 2022 - Workshop su AI per l'Industria, Online conference, 10/02/2022
See at:
CNR ExploRA | www.ital-ia2022.it
2022
Conference article
Open Access
AIMH Lab: Smart Cameras for Public Administration
Ciampi L., Cafarelli D., Carrara F., Di Benedetto M., Falchi F., Gennaro C., Massoli F. V., Messina N., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Public Administration. In particular, we present some AI-based public services serving the citizens that help achieve common goals beneficial to the society, putting humans at the epicenter. Through the automatic analysis of images gathered from city cameras, we provide AI applications ranging from smart parking and smart mobility to human activity monitoring.Source: Ital-IA 2022 - Workshop su AI per la Pubblica Amministrazione, Online conference, 10/02/2022
Ciampi L., Cafarelli D., Carrara F., Di Benedetto M., Falchi F., Gennaro C., Massoli F. V., Messina N., Amato G.
In this short paper, we report the activities of the Artificial Intelligence for Media and Humanities (AIMH) laboratory of the ISTI-CNR related to Public Administration. In particular, we present some AI-based public services serving the citizens that help achieve common goals beneficial to the society, putting humans at the epicenter. Through the automatic analysis of images gathered from city cameras, we provide AI applications ranging from smart parking and smart mobility to human activity monitoring.Source: Ital-IA 2022 - Workshop su AI per la Pubblica Amministrazione, Online conference, 10/02/2022
See at:
ISTI Repository | CNR ExploRA | www.ital-ia2022.it
2022
Conference article
Open Access
Counting or localizing? Evaluating cell counting and detection in microscopy images
Ciampi L., Carrara F., Amato G., Gennaro C.
Image-based automatic cell counting is an essential yet challenging task, crucial for the diagnosing of many diseases. Current solutions rely on Convolutional Neural Networks and provide astonishing results. However, their performance is often measured only considering counting errors, which can lead to masked mistaken estimations; a low counting error can be obtained with a high but equal number of false positives and false negatives. Consequently, it is hard to determine which solution truly performs best. In this work, we investigate three general counting approaches that have been successfully adopted in the literature for counting several different categories of objects. Through an experimental evaluation over three public collections of microscopy images containing marked cells, we assess not only their counting performance compared to several state-of-the-art methods but also their ability to correctly localize the counted cells. We show that commonly adopted counting metrics do not always agree with the localization performance of the tested models, and thus we suggest integrating the proposed evaluation protocol when developing novel cell counting solutions.Source: VISIGRAPP 2022 - 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, pp. 887–897, Online conference, 6-8/2/2022
DOI: 10.5220/0010923000003124
Project(s): AI4Media
Metrics:
Ciampi L., Carrara F., Amato G., Gennaro C.
Image-based automatic cell counting is an essential yet challenging task, crucial for the diagnosing of many diseases. Current solutions rely on Convolutional Neural Networks and provide astonishing results. However, their performance is often measured only considering counting errors, which can lead to masked mistaken estimations; a low counting error can be obtained with a high but equal number of false positives and false negatives. Consequently, it is hard to determine which solution truly performs best. In this work, we investigate three general counting approaches that have been successfully adopted in the literature for counting several different categories of objects. Through an experimental evaluation over three public collections of microscopy images containing marked cells, we assess not only their counting performance compared to several state-of-the-art methods but also their ability to correctly localize the counted cells. We show that commonly adopted counting metrics do not always agree with the localization performance of the tested models, and thus we suggest integrating the proposed evaluation protocol when developing novel cell counting solutions.Source: VISIGRAPP 2022 - 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, pp. 887–897, Online conference, 6-8/2/2022
DOI: 10.5220/0010923000003124
Project(s): AI4Media
Metrics:
See at:
ISTI Repository | CNR ExploRA | www.scitepress.org
2022
Contribution to book
Open Access
Training convolutional neural networks with competitive hebbian learning approaches
Lagani G., Falchi F., Gennaro C., Amato G.
We explore competitive Hebbian learning strategies to train feature detectors in Convolutional Neural Networks (CNNs), without supervision. We consider variants of the Winner-Takes-All (WTA) strategy explored in previous works, i.e. k-WTA, e-soft-WTA and p-soft-WTA, performing experiments on different object recognition datasets. Results suggest that the Hebbian approaches are effective to train early feature extraction layers, or to re-train higher layers of a pre-trained network, with soft competition generally performing better than other Hebbian approaches explored in this work. Our findings encourage a path of cooperation between neuroscience and computer science towards a deeper investigation of biologically inspired learning principles.Source: Machine Learning, Optimization, and Data Science, edited by Nicosia G., Ojha V., La Malfa E., La Malfa G., Jansen G., Pardalos P.M., Giuffrida G., Umeton R., pp. 25–40, 2022
DOI: 10.1007/978-3-030-95467-3_2
Project(s): AI4EU, AI4Media
Metrics:
Lagani G., Falchi F., Gennaro C., Amato G.
We explore competitive Hebbian learning strategies to train feature detectors in Convolutional Neural Networks (CNNs), without supervision. We consider variants of the Winner-Takes-All (WTA) strategy explored in previous works, i.e. k-WTA, e-soft-WTA and p-soft-WTA, performing experiments on different object recognition datasets. Results suggest that the Hebbian approaches are effective to train early feature extraction layers, or to re-train higher layers of a pre-trained network, with soft competition generally performing better than other Hebbian approaches explored in this work. Our findings encourage a path of cooperation between neuroscience and computer science towards a deeper investigation of biologically inspired learning principles.Source: Machine Learning, Optimization, and Data Science, edited by Nicosia G., Ojha V., La Malfa E., La Malfa G., Jansen G., Pardalos P.M., Giuffrida G., Umeton R., pp. 25–40, 2022
DOI: 10.1007/978-3-030-95467-3_2
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | ZENODO | link.springer.com | CNR ExploRA
2022
Contribution to book
Open Access
Evaluating hebbian learning in a semi-supervised setting
Lagani G., Falchi F., Gennaro C., Amato G.
We propose a semi-supervised learning strategy for deep Convolutional Neural Networks (CNNs) in which an unsupervised pre-training stage, performed using biologically inspired Hebbian learning algorithms, is followed by supervised end-to-end backprop fine-tuning. We explored two Hebbian learning rules for the unsupervised pre-training stage: soft-Winner-Takes-All (soft-WTA) and nonlinear Hebbian Principal Component Analysis (HPCA). Our approach was applied in sample efficiency scenarios, where the amount of available labeled training samples is very limited, and unsupervised pre-training is therefore beneficial. We performed experiments on CIFAR10, CIFAR100, and Tiny ImageNet datasets. Our results show that Hebbian outperforms Variational Auto-Encoder (VAE) pre-training in almost all the cases, with HPCA generally performing better than soft-WTA.Source: Machine Learning, Optimization, and Data Science, edited by Nicosia G.; Ojha V.; La Malfa E.; La Malfa G.; Jansen G.; Pardalos P.M.; Giuffrida G.; Umeton R., pp. 365–379, 2022
DOI: 10.1007/978-3-030-95470-3_28
Project(s): AI4EU, AI4Media
Metrics:
Lagani G., Falchi F., Gennaro C., Amato G.
We propose a semi-supervised learning strategy for deep Convolutional Neural Networks (CNNs) in which an unsupervised pre-training stage, performed using biologically inspired Hebbian learning algorithms, is followed by supervised end-to-end backprop fine-tuning. We explored two Hebbian learning rules for the unsupervised pre-training stage: soft-Winner-Takes-All (soft-WTA) and nonlinear Hebbian Principal Component Analysis (HPCA). Our approach was applied in sample efficiency scenarios, where the amount of available labeled training samples is very limited, and unsupervised pre-training is therefore beneficial. We performed experiments on CIFAR10, CIFAR100, and Tiny ImageNet datasets. Our results show that Hebbian outperforms Variational Auto-Encoder (VAE) pre-training in almost all the cases, with HPCA generally performing better than soft-WTA.Source: Machine Learning, Optimization, and Data Science, edited by Nicosia G.; Ojha V.; La Malfa E.; La Malfa G.; Jansen G.; Pardalos P.M.; Giuffrida G.; Umeton R., pp. 365–379, 2022
DOI: 10.1007/978-3-030-95470-3_28
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | ZENODO | link.springer.com | CNR ExploRA
2022
Journal article
Open Access
An embedded toolset for human activity monitoring in critical environments
Di Benedetto M., Carrara F., Ciampi L., Falchi F., Gennaro C., Amato G.
In many working and recreational activities, there are scenarios where both individual and collective safety have to be constantly checked and properly signaled, as occurring in dangerous workplaces or during pandemic events like the recent COVID-19 disease. From wearing personal protective equipment to filling physical spaces with an adequate number of people, it is clear that a possibly automatic solution would help to check compliance with the established rules. Based on an off-the-shelf compact and low-cost hardware, we present a deployed real use-case embedded system capable of perceiving people's behavior and aggregations and supervising the appliance of a set of rules relying on a configurable plug-in framework. Working on indoor and outdoor environments, we show that our implementation of counting people aggregations, measuring their reciprocal physical distances, and checking the proper usage of protective equipment is an effective yet open framework for monitoring human activities in critical conditions.Source: Expert systems with applications 199 (2022). doi:10.1016/j.eswa.2022.117125
DOI: 10.1016/j.eswa.2022.117125
Project(s): AI4EU, AI4Media
Metrics:
Di Benedetto M., Carrara F., Ciampi L., Falchi F., Gennaro C., Amato G.
In many working and recreational activities, there are scenarios where both individual and collective safety have to be constantly checked and properly signaled, as occurring in dangerous workplaces or during pandemic events like the recent COVID-19 disease. From wearing personal protective equipment to filling physical spaces with an adequate number of people, it is clear that a possibly automatic solution would help to check compliance with the established rules. Based on an off-the-shelf compact and low-cost hardware, we present a deployed real use-case embedded system capable of perceiving people's behavior and aggregations and supervising the appliance of a set of rules relying on a configurable plug-in framework. Working on indoor and outdoor environments, we show that our implementation of counting people aggregations, measuring their reciprocal physical distances, and checking the proper usage of protective equipment is an effective yet open framework for monitoring human activities in critical conditions.Source: Expert systems with applications 199 (2022). doi:10.1016/j.eswa.2022.117125
DOI: 10.1016/j.eswa.2022.117125
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | CNR ExploRA
2022
Doctoral thesis
Open Access
Relational Learning in computer vision
Messina N.
The increasing interest in social networks, smart cities, and Industry 4.0 is encouraging the development of techniques for processing, understanding, and organizing vast amounts of data. Recent important advances in Artificial Intelligence brought to life a subfield of Machine Learning called Deep Learning, which can automatically learn common patterns from raw data directly, without relying on manual feature selection. This framework overturned many computer science fields, like Computer Vision and Natural Language Processing, obtaining astonishing results. Nevertheless, many challenges are still open. Although deep neural networks obtained impressive results on many tasks, they cannot perform non-local processing by explicitly relating potentially interconnected visual or textual entities. This relational aspect is fundamental for capturing high-level semantic interconnections in multimedia data or understanding the relationships between spatially distant objects in an image. This thesis tackles the relational understanding problem in Deep Neural Networks, considering three different yet related tasks: Relational Content-based Image Retrieval (R-CBIR), Visual-Textual Retrieval, and the Same-Different tasks. We use state-of-the-art deep learning methods for relational learning, such as the Relation Networks and the Transformer Networks for relating the different entities in an image or in a text.
Messina N.
The increasing interest in social networks, smart cities, and Industry 4.0 is encouraging the development of techniques for processing, understanding, and organizing vast amounts of data. Recent important advances in Artificial Intelligence brought to life a subfield of Machine Learning called Deep Learning, which can automatically learn common patterns from raw data directly, without relying on manual feature selection. This framework overturned many computer science fields, like Computer Vision and Natural Language Processing, obtaining astonishing results. Nevertheless, many challenges are still open. Although deep neural networks obtained impressive results on many tasks, they cannot perform non-local processing by explicitly relating potentially interconnected visual or textual entities. This relational aspect is fundamental for capturing high-level semantic interconnections in multimedia data or understanding the relationships between spatially distant objects in an image. This thesis tackles the relational understanding problem in Deep Neural Networks, considering three different yet related tasks: Relational Content-based Image Retrieval (R-CBIR), Visual-Textual Retrieval, and the Same-Different tasks. We use state-of-the-art deep learning methods for relational learning, such as the Relation Networks and the Transformer Networks for relating the different entities in an image or in a text.
See at:
etd.adm.unipi.it | ISTI Repository | CNR ExploRA
2022
Doctoral thesis
Open Access
Deep Learning techniques for visual counting
Ciampi L.
In this thesis, I investigated and enhanced Deep Learning (DL)-based techniques for the visual counting task, which automatically estimates the number of objects, such as people or vehicles, present in images and videos. Specifically, I tackled the problem related to the lack of data needed for training current DL-based solutions by exploiting synthetic data gathered from video games, employing Domain Adaptation strategies between different data distributions, and taking advantage of the redundant information characterizing datasets labeled by multiple annotators. Furthermore, I addressed the engineering challenges coming out of the adoption of DL-based techniques in environments with limited power resources, mainly due to the high computational budget the AI-based algorithms require.
Ciampi L.
In this thesis, I investigated and enhanced Deep Learning (DL)-based techniques for the visual counting task, which automatically estimates the number of objects, such as people or vehicles, present in images and videos. Specifically, I tackled the problem related to the lack of data needed for training current DL-based solutions by exploiting synthetic data gathered from video games, employing Domain Adaptation strategies between different data distributions, and taking advantage of the redundant information characterizing datasets labeled by multiple annotators. Furthermore, I addressed the engineering challenges coming out of the adoption of DL-based techniques in environments with limited power resources, mainly due to the high computational budget the AI-based algorithms require.
See at:
etd.adm.unipi.it | ISTI Repository | CNR ExploRA
2022
Dataset
Open Access
Night and day instance segmented park (NDISPark) dataset: a collection of images taken by day and by night for vehicle detection, segmentation and counting in parking areas
Ciampi L., Santiago C., Costeira J. P., Gennaro C., Amato G.
NDIS Park is a collection of images of parking lots for vehicle detection, segmentation, and counting. Each image is manually labeled with pixel-wise masks and bounding boxes localizing vehicle instances. The dataset includes 259 images depicting several parking areas describing most of the problematic situations that we can find in a real scenario: seven different cameras capture the images under various weather conditions and viewing angles. Another challenging aspect is the presence of partial occlusion patterns in many scenes such as obstacles (trees, lampposts, other cars) and shadowed cars. The main peculiarity is that images are taken during the day and the night, showing utterly different lighting conditions.Project(s): AI4EU, AI4Media
Ciampi L., Santiago C., Costeira J. P., Gennaro C., Amato G.
NDIS Park is a collection of images of parking lots for vehicle detection, segmentation, and counting. Each image is manually labeled with pixel-wise masks and bounding boxes localizing vehicle instances. The dataset includes 259 images depicting several parking areas describing most of the problematic situations that we can find in a real scenario: seven different cameras capture the images under various weather conditions and viewing angles. Another challenging aspect is the presence of partial occlusion patterns in many scenes such as obstacles (trees, lampposts, other cars) and shadowed cars. The main peculiarity is that images are taken during the day and the night, showing utterly different lighting conditions.Project(s): AI4EU
, AI4Media
See at:
ISTI Repository | CNR ExploRA | zenodo.org
2022
Journal article
Open Access
Learning to count biological structures with raters' uncertainty
Ciampi L., Carrara F., Totaro V., Mazziotti R., Lupori L., Santiago C., Amato G., Pizzorusso T., Gennaro C.
Exploiting well-labeled training sets has led deep learning models to astonishing results for counting biological structures in microscopy images. However, dealing with weak multi-rater annotations, i.e., when multiple human raters disagree due to non-trivial patterns, remains a relatively unexplored problem. More reliable labels can be obtained by aggregating and averaging the decisions given by several raters to the same data. Still, the scale of the counting task and the limited budget for labeling prohibit this. As a result, making the most with small quantities of multi-rater data is crucial. To this end, we propose a two-stage counting strategy in a weakly labeled data scenario. First, we detect and count the biological structures; then, in the second step, we refine the predictions, increasing the correlation between the scores assigned to the samples and the raters' agreement on the annotations. We assess our methodology on a novel dataset comprising fluorescence microscopy images of mice brains containing extracellular matrix aggregates named perineuronal nets. We demonstrate that we significantly enhance counting performance, improving confidence calibration by taking advantage of the redundant information characterizing the small sets of available multi-rater data.Source: Medical image analysis (Print) 80 (2022). doi:10.1016/j.media.2022.102500
DOI: 10.1016/j.media.2022.102500
Project(s): AI4Media
Metrics:
Ciampi L., Carrara F., Totaro V., Mazziotti R., Lupori L., Santiago C., Amato G., Pizzorusso T., Gennaro C.
Exploiting well-labeled training sets has led deep learning models to astonishing results for counting biological structures in microscopy images. However, dealing with weak multi-rater annotations, i.e., when multiple human raters disagree due to non-trivial patterns, remains a relatively unexplored problem. More reliable labels can be obtained by aggregating and averaging the decisions given by several raters to the same data. Still, the scale of the counting task and the limited budget for labeling prohibit this. As a result, making the most with small quantities of multi-rater data is crucial. To this end, we propose a two-stage counting strategy in a weakly labeled data scenario. First, we detect and count the biological structures; then, in the second step, we refine the predictions, increasing the correlation between the scores assigned to the samples and the raters' agreement on the annotations. We assess our methodology on a novel dataset comprising fluorescence microscopy images of mice brains containing extracellular matrix aggregates named perineuronal nets. We demonstrate that we significantly enhance counting performance, improving confidence calibration by taking advantage of the redundant information characterizing the small sets of available multi-rater data.Source: Medical image analysis (Print) 80 (2022). doi:10.1016/j.media.2022.102500
DOI: 10.1016/j.media.2022.102500
Project(s): AI4Media
Metrics:
See at:
ISTI Repository | CNR ExploRA | www.sciencedirect.com
2022
Journal article
Open Access
Multi-camera vehicle counting using edge-AI
Ciampi L., Gennaro C., Carrara F., Falchi F., Vairo C., Amato G.
This paper presents a novel solution to automatically count vehicles in a parking lot using images captured by smart cameras. Unlike most of the literature on this task, which focuses on the analysis of single images, this paper proposes the use of multiple visual sources to monitor a wider parking area from different perspectives. The proposed multi-camera system is capable of automatically estimating the number of cars present in the entire parking lot directly on board the edge devices. It comprises an on-device deep learning-based detector that locates and counts the vehicles from the captured images and a decentralized geometric-based approach that can analyze the inter-camera shared areas and merge the data acquired by all the devices. We conducted the experimental evaluation on an extended version of the CNRPark-EXT dataset, a collection of images taken from the parking lot on the campus of the National Research Council (CNR) in Pisa, Italy. We show that our system is robust and takes advantage of the redundant information deriving from the different cameras, improving the overall performance without requiring any extra geometrical information of the monitored scene.Source: Expert systems with applications (2022). doi:10.1016/j.eswa.2022.117929
DOI: 10.1016/j.eswa.2022.117929
Project(s): AI4EU, AI4Media
Metrics:
Ciampi L., Gennaro C., Carrara F., Falchi F., Vairo C., Amato G.
This paper presents a novel solution to automatically count vehicles in a parking lot using images captured by smart cameras. Unlike most of the literature on this task, which focuses on the analysis of single images, this paper proposes the use of multiple visual sources to monitor a wider parking area from different perspectives. The proposed multi-camera system is capable of automatically estimating the number of cars present in the entire parking lot directly on board the edge devices. It comprises an on-device deep learning-based detector that locates and counts the vehicles from the captured images and a decentralized geometric-based approach that can analyze the inter-camera shared areas and merge the data acquired by all the devices. We conducted the experimental evaluation on an extended version of the CNRPark-EXT dataset, a collection of images taken from the parking lot on the campus of the National Research Council (CNR) in Pisa, Italy. We show that our system is robust and takes advantage of the redundant information deriving from the different cameras, improving the overall performance without requiring any extra geometrical information of the monitored scene.Source: Expert systems with applications (2022). doi:10.1016/j.eswa.2022.117929
DOI: 10.1016/j.eswa.2022.117929
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | CNR ExploRA | www.sciencedirect.com
2022
Conference article
Open Access
VISIONE at Video Browser Showdown 2022
Amato G., Bolettieri P., Carrara F., Falchi F., Gennaro C., Messina N., Vadicamo L., Vairo C.
VISIONE is a content-based retrieval system that supports various search functionalities (text search, object/color-based search, semantic and visual similarity search, temporal search). It uses a full-text search engine as a search backend. In the latest version of our system, we modified the user interface, and we made some changes to the techniques used to analyze and search for videos.Source: MMM 2022 - 28th International Conference on Multimedia Modeling, pp. 543–548, Phu Quoc, Vietnam, 06-10/06/2022
DOI: 10.1007/978-3-030-98355-0_52
Project(s): AI4EU, AI4Media
Metrics:
Amato G., Bolettieri P., Carrara F., Falchi F., Gennaro C., Messina N., Vadicamo L., Vairo C.
VISIONE is a content-based retrieval system that supports various search functionalities (text search, object/color-based search, semantic and visual similarity search, temporal search). It uses a full-text search engine as a search backend. In the latest version of our system, we modified the user interface, and we made some changes to the techniques used to analyze and search for videos.Source: MMM 2022 - 28th International Conference on Multimedia Modeling, pp. 543–548, Phu Quoc, Vietnam, 06-10/06/2022
DOI: 10.1007/978-3-030-98355-0_52
Project(s): AI4EU
, AI4Media Metrics:
See at:
ISTI Repository | doi.org | link.springer.com | CNR ExploRA