no code implementations • 1 May 2024 • Konstantinos Apostolidis, Jakob Abesser, Luca Cuccovillo, Vasileios Mezaris
This paper presents a baseline approach and an experimental protocol for a specific content verification problem: detecting discrepancies between the audio and video modalities in multimedia content.
no code implementations • 29 Apr 2024 • Konstantinos Tsigos, Evlampios Apostolidis, Spyridon Baxevanakis, Symeon Papadopoulos, Vasileios Mezaris
The findings of our quantitative and qualitative evaluations document the advanced performance of the LIME explanation method against the other compared ones, and indicate this method as the most appropriate for explaining the decisions of the utilized deepfake detector.
no code implementations • 7 Mar 2024 • Mariano V. Ntrougkas, Nikolaos Gkalelis, Vasileios Mezaris
While some techniques for generating explanations have been proposed, primarily for Convolutional Neural Networks, adapting such techniques to the new paradigm of Vision Transformers is non-trivial.
no code implementations • 5 Dec 2023 • Evlampios Apostolidis, Konstantinos Apostolidis, Vasileios Mezaris
This paper presents a web-based tool that facilitates the production of tailored summaries for online sharing on social media.
1 code implementation • 5 Dec 2023 • Ioannis Kontostathis, Evlampios Apostolidis, Vasileios Mezaris
In this work, we present an integrated system for spatiotemporal summarization of 360-degrees videos.
1 code implementation • 4 Dec 2023 • Konstantinos Triaridis, Vasileios Mezaris
Recent image manipulation localization and detection techniques usually leverage forensic artifacts and traces that are produced by a noise-sensitive filter, such as SRM and Bayar convolution.
Ranked #1 on Image Manipulation Detection on DSO-1
1 code implementation • 28 Nov 2023 • Konstantinos Gkrispanis, Nikolaos Gkalelis, Vasileios Mezaris
Face detectors are becoming a crucial component of many applications, including surveillance, that often have to run on edge devices with limited processing power and memory.
no code implementations • 24 Aug 2023 • Dimitrios Daskalakis, Nikolaos Gkalelis, Vasileios Mezaris
In this paper, we introduce Masked Feature Modelling (MFM), a novel approach for the unsupervised pre-training of a Graph Attention Network (GAT) block.
1 code implementation • 18 Jan 2023 • Nikolaos Gkalelis, Dimitrios Daskalakis, Vasileios Mezaris
In this paper, Gated-ViGAT, an efficient approach for video event recognition, utilizing bottom-up (object) information, a new frame sampling policy and a gating mechanism is proposed.
1 code implementation • 18 Jan 2023 • Mariano Ntrougkas, Nikolaos Gkalelis, Vasileios Mezaris
TAME can easily be applied to any convolutional neural network (CNN) by streamlining the optimization of the attention mechanism's training method and the selection of target model's feature maps.
1 code implementation • 21 Nov 2022 • Damianos Galanopoulos, Vasileios Mezaris
In this paper we tackle the cross-modal video retrieval problem and, more specifically, we focus on text-to-video retrieval.
1 code implementation • 22 Sep 2022 • Ioanna Gkartzonika, Nikolaos Gkalelis, Vasileios Mezaris
In this paper two new learning-based eXplainable AI (XAI) methods for deep convolutional neural network (DCNN) image classifiers, called L-CAM-Fm and L-CAM-Img, are proposed.
1 code implementation • 20 Jul 2022 • Nikolaos Gkalelis, Dimitrios Daskalakis, Vasileios Mezaris
In this paper a pure-attention bottom-up approach, called ViGAT, that utilizes an object detector together with a Vision Transformer (ViT) backbone network to derive object and frame features, and a head network to process these features for the task of event recognition and explanation in video, is proposed.
1 code implementation • ACM ICMR 2022 • Evlampios Apostolidis, Georgios Balaouras, Vasileios Mezaris, Ioannis Patras
Instead of simply modeling the frames' dependencies based on global attention, our method integrates a concentrated attention mechanism that is able to focus on non-overlapping blocks in the main diagonal of the attention matrix, and to enrich the existing information by extracting and exploiting knowledge about the uniqueness and diversity of the associated frames of the video.
Ranked #1 on Unsupervised Video Summarization on TvSum
1 code implementation • IEEE International Symposium on Multimedia (ISM) 2021 • Evlampios Apostolidis, Georgios Balaouras, Vasileios Mezaris, Ioannis Patras
This paper presents a new method for supervised video summarization.
Ranked #1 on Video Summarization on SumMe
no code implementations • 15 Jan 2021 • Evlampios Apostolidis, Eleni Adamantidou, Alexandros I. Metsai, Vasileios Mezaris, Ioannis Patras
Video summarization technologies aim to create a concise and complete synopsis by selecting the most informative parts of the video content.
1 code implementation • IEEE Transactions on Circuits and Systems for Video Technology 2020 • Evlampios Apostolidis, Eleni Adamantidou, Alexandros I. Metsai, Vasileios Mezaris, Ioannis Patras
This paper presents a new method for unsupervised video summarization.
Ranked #3 on Unsupervised Video Summarization on TvSum
Generative Adversarial Network Unsupervised Video Summarization
1 code implementation • MultiMedia Modeling (MMM) 2019 • Evlampios Apostolidis, Eleni Adamantidou, Alexandros I. Metsai, Vasileios Mezaris, Ioannis Patras
Experimental evaluation on two datasets (SumMe and TVSum) documents the contribution of the attention auto-encoder to faster and more stable training of the model, resulting in a significant performance improvement with respect to the original model and demonstrating the competitiveness of the proposed SUM-GAN-AAE against the state of the art.
Ranked #6 on Unsupervised Video Summarization on SumMe
1 code implementation • AI4TV 2019 • Evlampios Apostolidis, Alexandros I. Metsai, Eleni Adamantidou, Vasileios Mezaris, Ioannis Patras
In this paper we present our work on improving the efficiency of adversarial training for unsupervised video summarization.
Ranked #5 on Unsupervised Video Summarization on TvSum
no code implementations • 25 Nov 2015 • Christos Tzelepis, Damianos Galanopoulos, Vasileios Mezaris, Ioannis Patras
In this work we deal with the problem of high-level event detection in video.
no code implementations • 27 Apr 2015 • Nikolaos Gkalelis, Vasileios Mezaris
In this paper, using a novel matrix factorization and simultaneous reduction to diagonal form approach (or in short simultaneous reduction approach), Accelerated Kernel Discriminant Analysis (AKDA) and Accelerated Kernel Subclass Discriminant Analysis (AKSDA) are proposed.
1 code implementation • 15 Apr 2015 • Christos Tzelepis, Vasileios Mezaris, Ioannis Patras
In this paper, we propose a maximum margin classifier that deals with uncertainty in data input.