Thinesh Thiyakesan Ponbagavathi

Thinesh Thiyakesan Ponbagavathi

PhD Candidate in Computer Science

Stuttgart, Germany

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About

My research focusses on parameter-efficient fine-tuning techniques to adapt vision foundation models for fine-grained video understanding, with a focus on group activity understanding, cross-view generalization, and human-robot interaction.

Currently, I am a PhD candidate in Computer Science at the University of Stuttgart, advised by Prof. Dr. Alina Roitberg, and a scholar at IMPRS-IS. I joined Amazon as an Applied Scientist Intern in Santa Clara, California. Previously, I worked at Robert Bosch GmbH as a working student and at Johnson Controls as a Lead Controls Engineer.

News

University of Stuttgart IMPRS-IS IntCDC University of Hildesheim Amazon

Publications

Not All Layers Are Equal teaser
NeurIPS 2026

Not All Layers Are Equal in Image-to-Video Transfer

Thinesh Thiyakesan Ponbagavathi, Constantin Seibold, Alina Roitberg

Frame2Freq teaser
CVPR 2026

Frame2Freq: Spectral Adapters for Fine-Grained Video Understanding

Thinesh Thiyakesan Ponbagavathi, Constantin Seibold, Alina Roitberg

@InProceedings{Ponbagavathi_2026_CVPR,
    author    = {Ponbagavathi, Thinesh Thiyakesan and Seibold, Constantin and Roitberg, Alina},
    title     = {Frame2Freq: Spectral Adapters for Fine-Grained Video Understanding},
    booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
    month     = {June},
    year      = {2026},
    pages     = {24073-24083}
}
Order Matters teaser
ICRA 2026

Order Matters: On Parameter-Efficient Image-to-Video Probing for Recognizing Nearly Symmetric Actions

Thinesh Thiyakesan Ponbagavathi, Alina Roitberg

@INPROCEEDINGS{ponbagavathi2025order,
  author={Ponbagavathi, Thinesh Thiyakesan and Roitberg, Alina},
  booktitle={2026 IEEE International Conference on Robotics and Automation (ICRA)}, 
  title={Order Matters: On Parameter-Efficient Image-to-Video Probing for Recognizing Nearly Symmetric Actions}, 
  year={2026},
  volume={},
  number={},
  pages={17675-17682},
  keywords={Modeling;Probes;Printing;Videos;Accuracy;Robots;Human-robot interaction;Conferences;Tuning;Foundation models},
  doi={10.1109/ICRA57385.2026.11695733}}
ProGraD teaser
SAUAFG Workshop · CVPR 2026

Structured Relational Reasoning for Group Activity Assessment

Thinesh Thiyakesan Ponbagavathi*, Chengzheng Yang*, Alina Roitberg (*equal contribution)

@InProceedings{Ponbagavathi_2026_CVPRW,
    author    = {Ponbagavathi, Thinesh Thiyakesan and Yang, Chengzheng and Roitberg, Alina},
    title     = {Structured Relational Reasoning for Group Activity Assessment},
    booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) Workshops},
    month     = {June},
    year      = {2026},
    pages     = {8931-8940}
}
PDNet teaser
VISAPP 2026 · Oral

PDNet: Exploring Pruning and Distillation for Real-Time Worker Activity Recognition in Industrial Assembly

Malek Baba, Thinesh Thiyakesan Ponbagavathi, Alina Roitberg

@conference{visapp26,
author={Malek Baba and Thinesh Thiyakesan Ponbagavathi and Alina Roitberg},
title={PDNet: Exploring Pruning and Distillation for Real-Time Worker Activity Recognition in Industrial Assembly},
booktitle={Proceedings of the 21st International Conference on Computer Vision Theory and Applications - Volume 3: VISAPP},
year={2026},
pages={624-630},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0014477200004084},
isbn={978-989-758-804-4},
}
T-MASK teaser
ITSC 2025 · Best Student Paper Finalist 🏆

T-MASK: Temporal Masking for Probing Foundation Models across Camera Views in Driver Monitoring

Thinesh Thiyakesan Ponbagavathi, Kunyu Peng, Alina Roitberg

@INPROCEEDINGS{T_MASK_Ponbagavathi,
  author={Ponbagavathi, Thinesh Thiyakesan and Peng, Kunyu and Roitberg, Alina},
  booktitle={2025 IEEE 28th International Conference on Intelligent Transportation Systems (ITSC)}, 
  title={T-Mask: Temporal Masking for Probing Foundation Models Across Camera Views in Driver Monitoring}, 
  year={2025},
  volume={},
  number={},
  pages={2927-2934},
  keywords={Training;Accuracy;Sensitivity;Foundation models;Activity recognition;Benchmark testing;Cameras;Robustness;Monitoring;Videos;Driver Activity Recognition;Cross-view Generalization;Vision Foundation Models},
  doi={10.1109/ITSC60802.2025.11423550}}

Education

2024 – Present

Ph.D. Computer Science

University of Stuttgart · IMPRS-IS

Advised by Prof. Dr. Alina Roitberg. Research on parameter-efficient adaptation of vision foundation models for fine-grained video understanding.

2021 – 2023

M.Sc. Electrical Engineering (Smart Systems)

University of Stuttgart

Thesis: 3D-Aware Urban Scene Generation, advised by Prof. Dr. Bin Yang.