no code implementations • SLTAT (LREC) 2022 • Katerina Papadimitriou, Gerasimos Potamianos, Galini Sapountzaki, Theodore Goulas, Eleni Efthimiou, Stavroula-Evita Fotinea, Petros Maragos
There has been increasing interest lately in developing education tools for sign language (SL) learning that enable self-assessment and objective evaluation of learners’ SL productions, assisting both students and their instructors.
1 code implementation • ICML 2020 • Georgios Smyrnis, Petros Maragos
The field of tropical algebra is closely linked with the domain of neural networks with piecewise linear activations, since their output can be described via tropical polynomials in the max-plus semiring.
no code implementations • 19 Mar 2025 • Stelios Zarifis, Ioannis Kordonis, Petros Maragos
We propose Diffusion-Informed Model Predictive Control (D-I MPC), a generic framework for uncertainty-aware prediction and decision-making in partially observable stochastic systems by integrating diffusion-based time series forecasting models in Model Predictive Control algorithms.
no code implementations • 4 Mar 2025 • Chrysa Pratikaki, Panagiotis Filntisis, Athanasios Katsamanis, Anastasios Roussos, Petros Maragos
Sign Languages are the primary form of communication for Deaf communities across the world.
1 code implementation • 26 Nov 2024 • Davyd Svyezhentsev, George Retsinas, Petros Maragos
We extend this trend to the video domain applying it to the task of action recognition.
no code implementations • 5 Sep 2024 • Konstantinos Fotopoulos, Petros Maragos, Panagiotis Misiakos
To the best of our knowledge, it is the first method that achieves this using tropical geometry.
1 code implementation • 17 Apr 2024 • George Retsinas, Niki Efthymiou, Petros Maragos
We have validated the effectiveness of the proposed implicit-based approach for a synthetic test set, as well as provided qualitative results for a small set of real acquired point clouds with depth sensors.
1 code implementation • CVPR 2024 • George Retsinas, Panagiotis P. Filntisis, Radek Danecek, Victoria F. Abrevaya, Anastasios Roussos, Timo Bolkart, Petros Maragos
Instead, SMIRK replaces the differentiable rendering with a neural rendering module that, given the rendered predicted mesh geometry, and sparsely sampled pixels of the input image, generates a face image.
1 code implementation • 11 Dec 2023 • Georgios Milis, Panagiotis P. Filntisis, Anastasios Roussos, Petros Maragos
Our method, which we call NEUral Text to ARticulate Talk (NEUTART), is a talking face generator that uses a joint audiovisual feature space, as well as speech-informed 3D facial reconstructions and a lip-reading loss for visual supervision.
2 code implementations • 24 Oct 2023 • Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
In this paper, we study whether music source separation can be used as a pre-training strategy for music representation learning, targeted at music classification tasks.
1 code implementation • 3 Oct 2023 • Athanasios Glentis Georgoulakis, George Retsinas, Petros Maragos
Neural Network pruning is an increasingly popular way for producing compact and efficient models, suitable for resource-limited environments, while preserving high performance.
no code implementations • 25 Sep 2023 • Ioannis Kordonis, Emmanouil Theodosis, George Retsinas, Petros Maragos
Matrix Factorization (MF) has found numerous applications in Machine Learning and Data Mining, including collaborative filtering recommendation systems, dimensionality reduction, data visualization, and community detection.
1 code implementation • 6 Aug 2023 • Ioannis Pikoulis, Panagiotis P. Filntisis, Petros Maragos
In this paper, we investigate the emotion manipulation capabilities of diffusion models with "in-the-wild" images, a rather unexplored application area relative to the vast and rapidly growing literature for image-to-image translation tasks.
no code implementations • 27 Jun 2023 • Ioannis Kordonis, Petros Maragos
Furthermore, we develop a relationship of tropical polynomial division with the computation of the convex hull of unions of convex polyhedra and use it to derive an exact algorithm for tropical polynomial division.
no code implementations • 19 May 2023 • Ioanna Diamanti, Antigoni Tsiami, Petros Koutras, Petros Maragos
We introduce ViDaS, a two-stream, fully convolutional Video, Depth-Aware Saliency network to address the problem of attention modeling ``in-the-wild", via saliency prediction in videos.
1 code implementation • 25 Mar 2023 • Stamatis Alexandropoulos, Christos Sakaridis, Petros Maragos
Motivated by this prior, we design a novel two-head network, named Offset Vector Network (OVeNet), which generates both standard semantic predictions and a dense 2D offset vector field indicating the offset from each pixel to the respective seed pixel, which is used to compute an alternative, seed-based semantic prediction.
1 code implementation • 20 Feb 2023 • Nikolaos Kegkeroglou, Panagiotis P. Filntisis, Petros Maragos
In this paper, we conduct insightful studies about the effect of face occlusion on emotion recognition performance, and showcase the superiority of full body input over the plain masked face.
1 code implementation • 14 Feb 2023 • Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
Contrastive learning constitutes an emerging branch of self-supervised learning that leverages large amounts of unlabeled data, by learning a latent space, where pairs of different views of the same sample are associated.
no code implementations • 23 Oct 2022 • Andreas Georgis, Panagiotis Mermigkas, Petros Maragos
Traditional monocular Visual Simultaneous Localization and Mapping (vSLAM) systems can be divided into three categories: those that use features, those that rely on the image itself, and hybrid models.
1 code implementation • 28 Sep 2022 • Petros Tzathas, Petros Maragos, Anastasios Roussos
In recent years, implicit surface representations through neural networks that encode the signed distance have gained popularity and have achieved state-of-the-art results in various tasks (e. g. shape representation, shape reconstruction, and learning shape priors).
no code implementations • 3 Sep 2022 • Christina O. Tze, Panagiotis P. Filntisis, Athanasia-Lida Dimou, Anastasios Roussos, Petros Maragos
In this paper, we introduce a neural rendering pipeline for transferring the facial expressions, head pose, and body movements of one person in a source video to another in a target video.
1 code implementation • 22 Jul 2022 • Panagiotis P. Filntisis, George Retsinas, Foivos Paraperas-Papantoniou, Athanasios Katsamanis, Anastasios Roussos, Petros Maragos
The recent state of the art on monocular 3D face reconstruction from image data has made some impressive advancements, thanks to the advent of Deep Learning.
1 code implementation • 20 Feb 2022 • Kleanthis Avramidis, Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
The study of Music Cognition and neural responses to music has been invaluable in understanding human emotions.
1 code implementation • CVPR 2022 • Foivos Paraperas Papantoniou, Panagiotis P. Filntisis, Petros Maragos, Anastasios Roussos
In this paper, we introduce a novel deep learning method for photo-realistic manipulation of the emotional state of actors in "in-the-wild" videos.
no code implementations • 29 Sep 2021 • George Retsinas, Giorgos Sfikas, Panagiotis Filntisis, Petros Maragos
Selecting an appropriate learning rate for efficiently training deep neural networks is a difficult process that can be affected by numerous parameters, such as the dataset, the model architecture or even the batch size.
no code implementations • ICLR 2022 • Panagiotis Misiakos, Georgios Smyrnis, George Retsinas, Petros Maragos
Based on this result, we propose geometrical neural network compression methods that employ the K-means algorithm.
1 code implementation • 7 Jul 2021 • Panagiotis Antoniadis, Ioannis Pikoulis, Panagiotis P. Filntisis, Petros Maragos
In this work we tackle the task of video-based audio-visual emotion recognition, within the premises of the 2nd Workshop and Competition on Affective Behavior Analysis in-the-wild (ABAW2).
no code implementations • 26 Jun 2021 • Vasiliki I. Vasileiou, Nikolaos Kardaris, Petros Maragos
Nowadays, the interaction between humans and robots is constantly expanding, requiring more and more human motion recognition applications to operate in real time.
1 code implementation • 7 Jun 2021 • Panagiotis Antoniadis, Panagiotis P. Filntisis, Petros Maragos
To evaluate the performance of our method under real-world conditions we perform extensive experiments on the AffectNet and Aff-Wild2 datasets.
Ranked #12 on
Facial Expression Recognition (FER)
on AffectNet
(Accuracy (7 emotion) metric)
Facial Expression Recognition
Facial Expression Recognition (FER)
+1
1 code implementation • 16 May 2021 • Ioannis Pikoulis, Panagiotis P. Filntisis, Petros Maragos
In this work we tackle the task of video-based visual emotion recognition in the wild.
Ranked #3 on
Emotion Recognition in Context
on BoLD
no code implementations • 7 Mar 2021 • Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
The advent of deep learning has led to the prevalence of deep neural network architectures for monaural music source separation, with end-to-end approaches that operate directly on the waveform level increasingly receiving research attention.
no code implementations • 13 Feb 2021 • Kleanthis Avramidis, Agelos Kratimenos, Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
Sound Event Detection and Audio Classification tasks are traditionally addressed through time-frequency representations of audio signals such as spectrograms.
1 code implementation • ICCV 2021 • Markos Diomataris, Nikolaos Gkanatsios, Vassilis Pitsikalis, Petros Maragos
Scene Graph Generators (SGGs) are models that, given an image, build a directed graph where each edge represents a predicted subject predicate object triplet.
no code implementations • 28 Dec 2020 • Vasiliki Tassopoulou, George Retsinas, Petros Maragos
In our work, we utilize a Multi-task Learning scheme, training the model to perform decompositions of the target sequence with target units of different granularity, from fine to coarse.
no code implementations • 24 Nov 2020 • Agelos Kratimenos, Georgios Pavlakos, Petros Maragos
Independent Sign Language Recognition is a complex visual recognition problem that combines several challenging tasks of Computer Vision due to the necessity to exploit and fuse information from hand gestures, body features and facial expressions.
no code implementations • 15 Nov 2020 • Nikolaos Dimitriadis, Petros Maragos
In this paper we study an emerging class of neural networks based on the morphological operators of dilation and erosion.
no code implementations • 6 Nov 2020 • Nikos Tsilivis, Anastasios Tsiamis, Petros Maragos
In this work, we study the problem of finding approximate, with minimum support set, solutions to matrix max-plus equations, which we call sparse approximate solutions.
no code implementations • 30 Oct 2020 • Kleanthis Avramidis, Athanasia Zlatintsi, Christos Garoufis, Petros Maragos
Emotion Recognition from EEG signals has long been researched as it can assist numerous medical and rehabilitative applications.
1 code implementation • 30 Oct 2020 • Panagiotis Paraskevas Filntisis, Niki Efthymiou, Gerasimos Potamianos, Petros Maragos
We present our winning submission to the First International Workshop on Bodily Expressed Emotion Understanding (BEEU) challenge.
no code implementations • 28 Aug 2020 • Niki Efthymiou, Panagiotis P. Filntisis, Petros Koutras, Antigoni Tsiami, Jack Hadfield, Gerasimos Potamianos, Petros Maragos
In this paper we present an integrated robotic system capable of participating in and performing a wide range of educational and entertainment tasks, in collaboration with one or more children.
no code implementations • 17 Aug 2020 • George Retsinas, Giorgos Sfikas, Petros Maragos
The related joint loss leads to a boost in recognition performance, while the Seq2Seq branch is used to create efficient word representations.
1 code implementation • 9 Jun 2020 • Georgia Chalvatzaki, Nikolaos Gkanatsios, Petros Maragos, Jan Peters
Inherent morphological characteristics in objects may offer a wide range of plausible grasping orientations that obfuscates the visual learning of robotic grasping.
1 code implementation • 4 Jun 2020 • George Retsinas, Athena Elafrou, Georgios Goumas, Petros Maragos
Pruning neural networks has regained interest in recent years as a means to compress state-of-the-art deep neural networks and enable their deployment on resource-constrained devices.
1 code implementation • 21 Apr 2020 • Isidoros Marougkas, Petros Koutras, Nikos Kardaris, Georgios Retsinas, Georgia Chalvatzaki, Petros Maragos
We present a novel multi-attentional convolutional architecture to tackle the problem of real-time RGB-D 6D object pose tracking of single, known objects.
1 code implementation • CVPR 2020 • Antigoni Tsiami, Petros Koutras, Petros Maragos
We introduce STAViS, a spatio-temporal audiovisual saliency network that combines spatio-temporal visual and auditory information in order to efficiently address the problem of saliency estimation in videos.
no code implementations • 9 Dec 2019 • Petros Maragos, Emmanouil Theodosis
Tropical Geometry and Mathematical Morphology share the same max-plus and min-plus semiring arithmetic and matrix algebra.
no code implementations • 29 Nov 2019 • Georgios Smyrnis, Petros Maragos
In this work, we examine the process of Tropical Polynomial Division, a geometric method which seeks to emulate the division of regular polynomials, when applied to those of the max-plus semiring.
1 code implementation • 28 Nov 2019 • Agelos Kratimenos, Kleanthis Avramidis, Christos Garoufis, Athanasia Zlatintsi, Petros Maragos
Instrument classification is one of the fields in Music Information Retrieval (MIR) that has attracted a lot of research interest.
no code implementations • 28 Jun 2019 • Nikos Melanitis, Petros Maragos
We introduce a linear method to self-calibrate and find the metric reconstruction of a camera pair.
no code implementations • 28 May 2019 • George Retsinas, Athena Elafrou, Georgios Goumas, Petros Maragos
In this paper, we introduce Channel-wise recurrent convolutional neural networks (RecNets), a family of novel, compact neural network architectures for computer vision tasks inspired by recurrent neural networks (RNNs).
1 code implementation • 15 Feb 2019 • Nikolaos Gkanatsios, Vassilis Pitsikalis, Petros Koutras, Athanasia Zlatintsi, Petros Maragos
Detecting visual relationships, i. e. <Subject, Predicate, Object> triplets, is a challenging Scene Understanding task approached in the past via linguistic priors or spatial information in a single feature branch.
1 code implementation • 7 Jan 2019 • Panagiotis P. Filntisis, Niki Efthymiou, Petros Koutras, Gerasimos Potamianos, Petros Maragos
In this paper we address the problem of multi-cue affect recognition in challenging scenarios such as child-robot interaction.
no code implementations • 8 Dec 2018 • Stefanos Pertigkiozoglou, Petros Maragos
This paper focuses on the detection of adversarial examples, which are created for convolutional neural networks that perform image classification.
no code implementations • 3 Dec 2018 • Petros Koutras, Petros Maragos
In this work we propose a multi-task spatio-temporal network, called SUSiNet, that can jointly tackle the spatio-temporal problems of saliency estimation, action recognition and video summarization.
Ranked #66 on
Action Recognition
on HMDB-51
(using extra training data)
no code implementations • 1 Dec 2018 • Georgia Chalvatzaki, Petros Koutras, Jack Hadfield, Xanthi S. Papageorgiou, Costas S. Tzafestas, Petros Maragos
In this work, we present a novel framework for on-line human gait stability prediction of the elderly users of an intelligent robotic rollator using Long Short Term Memory (LSTM) networks, fusing multimodal RGB-D and Laser Range Finder (LRF) data from non-wearable sensors.
no code implementations • 1 Dec 2018 • Jack Hadfield, Georgia Chalvatzaki, Petros Koutras, Mehdi Khamassi, Costas S. Tzafestas, Petros Maragos
In this work we tackle the problem of child engagement estimation while children freely interact with a robot in their room.
no code implementations • 1 Nov 2018 • Emmanouil Theodosis, Petros Maragos
Weighted Finite State Transducers (WFSTs) are versatile data structures that can model a great number of problems, ranging from Automatic Speech Recognition to DNA sequencing.
Automatic Speech Recognition
Automatic Speech Recognition (ASR)
+1
no code implementations • 1 Nov 2018 • Emmanouil Theodosis, Petros Maragos
In particular, the proposed algorithm tries to localise the attacker by adapting the leniency parameter based on estimates about the state of the solution space.
no code implementations • 22 May 2018 • Vasileios Charisopoulos, Petros Maragos
We present a new, unifying approach following some recent developments on the complexity of neural networks with piecewise linear activations.
1 code implementation • CVPR 2018 • Giorgos Bouritsas, Petros Koutras, Athanasia Zlatintsi, Petros Maragos
Despite the availability of a huge amount of video data accompanied by descriptive texts, it is not always easy to exploit the information contained in natural language in order to automatically recognize video concepts.
no code implementations • 12 Oct 2017 • Nikolaos Kolotouros, Petros Maragos
In this paper we present a new framework for the solution of active contour models on graphs.
no code implementations • 24 Oct 2016 • Christos Sakaridis, Kimon Drakopoulos, Petros Maragos
Active contour models based on partial differential equations have proved successful in image segmentation, yet the study of their geometric formulation on arbitrary geometric graphs is still at an early stage.
no code implementations • LREC 2014 • Luca Cristoforetti, Mirco Ravanelli, Maurizio Omologo, Aless Sosi, ro, Alberto Abad, Martin Hagmueller, Petros Maragos
This paper describes a multi-microphone multi-language acoustic corpus being developed under the EC project Distant-speech Interaction for Robust Home Applications (DIRHA).
no code implementations • 29 Jun 2009 • Nikolaos Vasiloglou, Petros Maragos
In this paper we compute the Fourier spectrum of the Fractal Interpolation Functions FIFs as introduced by Michael Barnsley.
Information Theory Information Theory