Giorgos Tolias

associate professor - CTU in Prague / Fac. of Electrical Engineering / Dep. of Cybernetics
computer vision researcher - Visual Recognition Group

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I am an associate professor at CTU in Prague and a researcher leading a team at the Visual Recognition Group (VRG). I received my PhD in December 2013 from NTUA, Greece, under the supervision of Yannis Avrithis and Stefanos Kollias. From 2014 to 2015, I was a postdoctoral researcher at Inria Rennes, France, working with Hervé Jégou. In 2015, I moved to Prague for a postdoc at CTU with Ondřej Chum.

My team is currently funded by a 5 years “Junior Star” starting grant from the Czech science foundation and by two MSCA post-doctoral fellowships. My research focuses on computer vision, particularly on visual representation learning and crafting, as well as large-scale object retrieval and recognition, among other topics. I also care about the responsible use of AI and remain opposed to potential military and surveillance applications. Despite my work with digital images, my heart still belongs to analog photography and the darkroom, where I continue to enjoy working with film.

news

Sep 01, 2025 I will be attending ICCV 2025. See you in Hawaii!

team

post-doc Bill Psomas
phd student Nikos Efthymiadis co-advised with Ondrej Chum
phd student Pavel Suma
phd student Vladan Stojnic
phd student Tilemachos Aravanis


awards

outstanding reviewer award at CVPR '25, '21, '20, '18, '17, ICCV '17, BMVC '17


organization

2025 instance-level recognition and generation workshop ICCV'25
2021 image similarity challenge competition NeurIPS'21
2020 - 2024 instance-level recognition workshop ECCV'20 ICCV'21 ECCV'22 ECCV'24
2018 - 2019 large-scale landmark recognition workshop CVPR'18 CVPR'19
2016 - 2018 computer vision and sports summer school (VS3) 2016 2017 2018


tutorials

2021 - 2023 large-scale visual localization CVPR '23 ICCV '21
2017 - 2019 large-scale visual place recognition and image-based localization ICCV '19 ICCV '21


community services

area chair CVPR'26 ICCV'25 ECCV'24 ECCV'22
associate editor IJCV (2022-today)
reviewer (regularly) CVPR ICCV ECCV WACV
reviewer (occasionally) NeurIPS BMVC
reviewer (past) ACM MM


teaching

2025 - today deep learning (23% share, bc/msc)
2021 - today computer vision methods (23% share, msc)
2017 - today reading group in pattern recognition and computer vision (50% share, doctoral/msc)


selected publications

complete publication list
  1. NeurIPS
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    Instance-Level Composed Image Retrieval
    Bill Psomas, George Retsinas, Nikos Efthymiadis, and 5 more authors
    In NeurIPS, 2025
  2. ICCV
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    Processing and acquisition traces in visual encoders: What does CLIP know about your camera?
    Ryan Ramos, Vladan Stojnić, Giorgos Kordopatis-Zilos, and 3 more authors
    In ICCV, 2025
  3. CVPR
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    ILIAS: Instance-Level Image retrieval At Scale
    Giorgos Kordopatis-Zilos, Vladan Stojnić, Anna Manko, and 7 more authors
    In CVPR, 2025
  4. CVPR
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    LPOSS: Label Propagation Over Patches and Pixels for Open-vocabulary Semantic Segmentation
    Vladan Stojnic, Yannis Kalantidis, Jiri Matas, and 1 more author
    In CVPR, 2025
  5. CVPR
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    LOCORE: Image Re-ranking with Long-Context Sequence Modeling
    Zilin Xiao, Pavel Suma, Ayush Sachdeva, and 4 more authors
    In CVPR, 2025
  6. WACV
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    Composed Image Retrieval for Training-Free Domain Conversion
    Nikos Efthymiadis, Bill Psomas, Zakaria Laskar, and 4 more authors
    In WACV, 2025
  7. WACV
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    Crafting Distribution Shifts for Validation and Training in Single Source Domain Generalization
    Nikos Efthymiadis, Giorgos Tolias, and Ondrej Chum
    In WACV, 2025
  8. ECCV
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    AMES: Asymmetric and Memory-Efficient Similarity Estimation for Instance-level Retrieval
    Pavel Suma, Giorgos Kordopatis-Zilos, Ahmet Iscen, and 1 more author
    In ECCV, 2024
  9. CVPR
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    Label Propagation for Zero-shot Classification with Vision-Language Models
    Vladan Stojnic, Yannis Kalantidis, and Giorgos Tolias
    In CVPR, 2024
  10. IJCV
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    HSCNet++: Hierarchical Scene Coordinate Classification and Regression for Visual Localization with Transformer
    Shuzhe Wang, Zakaria Laskar, Iaroslav Melekhov, and 4 more authors
    IJCV, 2024
  11. NeurIPS
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    Test-time Training for Matching-based Video Object Segmentation
    Juliette Bertrand, Giorgos Kordopatis-Zilos, Yannis Kalantidis, and 1 more author
    In NeurIPS, 2023
  12. CVPRW
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    Self-Supervised Video Similarity Learning
    Giorgos Kordopatis-Zilos, Giorgos Tolias, Christos Tzelepis, and 3 more authors
    In CVPR workshop - L3D-IVU, 2023