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Ioannis Patras

28 accepted papers

2026

Beyond Linear Probes: Dynamic Safety Monitoring for Language Models

ICLR 2026poster

Monitoring large language models' (LLMs) activations is an effective way to detect harmful requests before they lead to unsafe outputs. However, traditional safety monitors often require the same amount of compute for every query. This creates a trade-off: expensive monitors waste resources on easy…

Cited by 0SourcecodeScholar
2026

Deconstructing the Failure of Ideal Noise Correction: A Three-Pillar Diagnosis

CVPR 2026

Statistically consistent methods based on the noise transition matrix (T) offer a theoretically grounded solution to Learning with Noisy Labels (LNL), with guarantees of convergence to the optimal clean-data classifier. In practice, however, these methods are often outperformed by empirical approach

Cited by 0SourceScholar
2026

Diffusion-Based Makeup Transfer with Facial Region-Aware Makeup Features

CVPR 2026

Current diffusion-based makeup transfer methods commonly use the makeup information encoded by off-the-shelf foundation models (e.g., CLIP) as condition to preserve the makeup style of reference image in the generation. Although effective, these works mainly have two limitations: (1) foundation mode

Cited by 0SourcecodeScholar
2025

$\boldsymbol{\lambda}$-Orthogonality Regularization for Compatible Representation Learning

NeurIPS 2025poster

Retrieval systems rely on representations learned by increasingly powerful models. However, due to the high training cost and inconsistencies in learned representations, there is significant interest in facilitating communication between representations and ensuring compatibility across independentl…

Cited by 0SourcecodeScholar
2025

AIM-Fair: Advancing Algorithmic Fairness via Selectively Fine-Tuning Biased Models with Contextual Synthetic Data

CVPR 2025poster

Recent advances in generative models have sparked research on improving model fairness with AI-generated data. However, existing methods often face limitations in the diversity and quality of synthetic data, leading to compromised fairness and overall model accuracy. Moreover, many approaches rely o…

2025

FairCoT: Enhancing Fairness in Text-to-Image Generation via Chain of Thought Reasoning with Multimodal Large Language Models

EMNLP 2025

In the domain of text-to-image generative models, biases inherent in training datasets often propagate into generated content, posing significant ethical challenges, particularly in socially sensitive contexts. We introduce FairCoT, a novel framework that enhances fairness in text-to-image models th

2025

Frequency-Guided Diffusion for Training-Free Text-Driven Image Translation

ICCV 2025poster

Current training-free text-driven image translation primarily uses diffusion features (convolution and attention) of pre-trained model as guidance to preserve the style/structure of source image in translated image. However, the coarse guidance at feature level struggles with style (e.g., visual pat…

Cited by 0SourcePDFScholar
2025

Get Confused Cautiously: Textual Sequence Memorization Erasure with Selective Entropy Maximization

COLING 2025main

Large Language Models (LLMs) have been found to memorize and recite some of the textual sequences from their training set verbatim, raising broad concerns about privacy and copyright issues. This Textual Sequence Memorization (TSM) phenomenon leads to a high demand to regulate LLM output to prevent…

2025

ReWind: Understanding Long Videos with Instructed Learnable Memory

CVPR 2025poster

Vision-Language Models (VLMs) are crucial for real-world applications that require understanding textual and visual information. However, existing VLMs face multiple challenges in processing long videos, including computational inefficiency, memory limitations, and difficulties maintaining coherent…

Cited by 0SourcePDFScholar
2025

Temporal Score Analysis for Understanding and Correcting Diffusion Artifacts

CVPR 2025poster

Visual artifacts remain a persistent challenge in diffusion models, even with training on massive datasets. Current solutions primarily rely on supervised detectors, yet lack understanding of why these artifacts occur in the first place. In our analysis, we identify three distinct phases in the diff…

Cited by 0SourcePDFScholar
2025

Towards Interpretability Without Sacrifice: Faithful Dense Layer Decomposition with Mixture of Decoders

NeurIPS 2025poster

Multilayer perceptrons (MLPs) are an integral part of large language models, yet their dense representations render them difficult to understand, edit, and steer. Recent methods learn interpretable approximations via neuron-level sparsity, yet fail to faithfully reconstruct the original mapping--sig…

Cited by 0SourcecodeScholar
2024

CemiFace: Center-based Semi-hard Synthetic Face Generation for Face Recognition

NeurIPS 2024poster

Privacy issue is a main concern in developing face recognition techniques. Although synthetic face images can partially mitigate potential legal risks while maintaining effective face recognition (FR) performance, FR models trained by face images synthesized by existing generative approaches frequen…

2024

Efficient Unsupervised Visual Representation Learning with Explicit Cluster Balancing

ECCV 2024poster

"Self-supervised learning has recently emerged as the preeminent pretraining paradigm across and between modalities, with remarkable results. In the image domain specifically, group (or cluster) discrimination has been one of the most successful methods. However, such frameworks need to guard agains…

2024

LAFS: Landmark-based Facial Self-supervised Learning for Face Recognition

CVPR 2024poster

In this work we focus on learning facial representations that can be adapted to train effective face recognition models particularly in the absence of labels. Firstly compared with existing labelled face datasets a vastly larger magnitude of unlabeled faces exists in the real world. We explore the l…

2024

Multilinear Mixture of Experts: Scalable Expert Specialization through Factorization

NeurIPS 2024poster

The Mixture of Experts (MoE) paradigm provides a powerful way to decompose dense layers into smaller, modular computations often more amenable to human interpretation, debugging, and editability. However, a major challenge lies in the computational cost of scaling the number of experts high enough t…

2023

A Simple Baseline for Knowledge-Based Visual Question Answering

EMNLP 2023short main

This paper is on the problem of Knowledge-Based Visual Question Answering (KB-VQA). Recent works have emphasized the significance of incorporating both explicit (through external databases) and implicit (through LLMs) knowledge to answer questions requiring external knowledge effectively. A common l…

Cited by 0SourcecodeScholar
2023

Attribute-Preserving Face Dataset Anonymization via Latent Code Optimization

CVPR 2023highlight

This work addresses the problem of anonymizing the identity of faces in a dataset of images, such that the privacy of those depicted is not violated, while at the same time the dataset is useful for downstream task such as for training machine learning models. To the best of our knowledge, we are th…

2023

DivClust: Controlling Diversity in Deep Clustering

CVPR 2023poster

Clustering has been a major research topic in the field of machine learning, one to which Deep Learning has recently been applied with significant success. However, an aspect of clustering that is not addressed by existing deep clustering methods, is that of efficiently producing multiple, diverse p…

2023

HyperReenact: One-Shot Reenactment via Jointly Learning to Refine and Retarget Faces

ICCV 2023poster

In this paper, we present our method for neural face reenactment, called HyperReenact, that aims to generate realistic talking head images of a source identity, driven by a target facial pose. Existing state-of-the-art face reenactment methods train controllable generative models that learn to synth…

Cited by 43PDFcodeScholar
2023

PandA: Unsupervised Learning of Parts and Appearances in the Feature Maps of GANs

ICLR 2023poster

Recent advances in the understanding of Generative Adversarial Networks (GANs) have led to remarkable progress in visual editing and synthesis tasks, capitalizing on the rich semantics that are embedded in the latent spaces of pre-trained GANs. However, existing methods are often tailored to specifi…

2023

Parts of Speech–Grounded Subspaces in Vision-Language Models

NeurIPS 2023poster

Latent image representations arising from vision-language models have proved immensely useful for a variety of downstream tasks. However, their utility is limited by their entanglement with respect to different visual attributes. For instance, recent work has shown that CLIP image representations ar…

2021

WarpedGANSpace: Finding Non-Linear RBF Paths in GAN Latent Space

ICCV 2021poster

This work addresses the problem of discovering, in an unsupervised manner, interpretable paths in the latent space of pretrained GANs, so as to provide an intuitive and easy way of controlling the underlying generative factors. In doing so, it addresses some of the limitations of the state-of-the-ar…

Cited by 66PDFcodeScholar
2019

Can Automatic Facial Expression Analysis Be Used for Treatment Outcome Estimation in Schizophrenia?

ICASSP 2019accepted

Negative symptoms of schizophrenia include expressive deficits that are marked by a reduction in patients' behaviour. Analysing automatically non-verbal behaviour and exploiting the results for estimating symptom severity has drawn attention recently. However, those approaches are not accurate enoug…

Cited by 0SourceScholar
2019

ViSiL: Fine-Grained Spatio-Temporal Video Similarity Learning

ICCV 2019oral

In this paper we introduce ViSiL, a Video Similarity Learning architecture that considers fine-grained Spatio-Temporal relations between pairs of videos -- such relations are typically lost in previous video retrieval approaches that embed the whole frame or even the whole video into a vector descri…

Cited by 100PDFcodeScholar