Krishna Kanth Nakka

I graduated with a PhD in Computer Science in August 2022 from the Computer Vision Lab at EPFL. I was supervised by Dr. Mathieu Salzmann and Prof. Pascal Fua in the areas of computer vision and deep learning.

Following the completion of my Ph.D., I worked as a postdoctoral scientist at the Visual Intelligence for Transportation Lab (VITA) at EPFL under the supervision of Prof. Alexandre Alahi until April 2023.

Before joining EPFL in 2017, I spent two years at Samsung Research Bangalore working on mobile camera algorithms. Prior to that, I graduated from the Department of Electrical Engineering at IIT Kharagpur in 2015 with a Dual degree (Masters and Bachelors).

During my undergraduate years, I interned at the University of Alberta, the University of Queensland, and Philips Research.

I'm currently working in the Privacy Team, Trustworthy Technology Lab at Huawei Munich Research Center focusing on the privacy of Large Language Models and Auto ML techniques for Differentially Private Federated Learning algorithms.

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Research

My overarching goal is to develop machine learning models that are both robust and privacy-aware, in the domains of safety and security-critical applications. In my current research, I concentrate on enhancing privacy aspects within Large Language Models (LLMs) and within the context of Federated Learning. Additionally, I explore AutoML techniques to optimize hyperparameters in the Federated Learning setting.

During my doctoral studies, my primary focus was on comprehending the limitations of deep neural networks concerning out-of-distribution and adversarial scenarios, with the aim of improving robustness against adversarial domain shifts. My research encompassed areas such as interpretable models, transfer-based black-box attacks, attack detection, adversarial defenses, anomaly detection, and the evaluation of disentangled representations. While at VITA, my research delved into various projects related to human-pose estimation, tracking, and re-identification, with a particular application in the field of team sports analytics.

I am enthusiastic about collaborating with motivated students and researchers who share an interest in Adversarial Machine Learning. If my research background aligns with your interests, please feel free to reach out to me via email.

teaser A unified framework for keypoint-based multi-person pose detection, tracking and re-identification for team sport analysis
Krishna Kanth Nakka

Innosuisse VITA-Dartfish, Sep 2022 - April 2023


The objective of this project is to enhance sports player tracking through a unified framework. This involves detecting and tracking semantic keypoints and utilizing re-identification techniques to enhance long-term tracking, especially when players go out of view.

teaser Understanding Pose and Appearance Disentanglement in 3D Human Pose Estimation
Krishna Kanth Nakka, Mathieu Salzmann
Preprint, 2022
Paper

Our analyses show that disentanglement in the three state-of-the-art disentangled representation learning frameworks is far from complete, and that their pose codes contain significant appearance information

teaser Universal, Transferable Adversarial Attacks for Visual Object Trackers
Krishna Kanth Nakka, Mathieu Salzmann
Paper
Adversarial Robustness Workshop, European Conference on Computer Vision (ECCV), 2022

We propose to learn to generate a single perturbation from the object template only, that can be added to every search image and still successfully fool the tracker for the entire video. As a consequence, the resulting generator outputs perturbations that are quasi-independent of the template, thereby making them universal perturbations.

teaser Learning Transferable Adversarial Perturbations
Krishna Kanth Nakka, Mathieu Salzmann
Neural Information and Processing Systems (NeurIPS), 2021
arXiv / code

We show that generators trained with mid-level feature separation loss transfers significantly better in cross-model, cross-domain and cross-task setting

teaser Towards Robust Fine-grained Recognition by Maximal Separation of Discriminative Features
Krishna Kanth Nakka, Mathieu Salzmann
Asian Conference on Computer Vision (ACCV), 2020
arXiv / code / Slides

We improve the robustness by introducing an attention-based regularization mechanism that maximally separates the latent features of discriminative regions of different classes while minimizing the contribution of the non-discriminative regions to the final class prediction.

teaser Indirect Local Attacks for Context-aware Semantic Segmentation Networks
Krishna Kanth Nakka, Mathieu Salzmann
European Conference on Computer Vision (ECCV), 2020 [Spotlight]
arXiv / code / Slides

We show that the resulting networks are sensitive not only to global attacks, where perturbations affect the entire input image, but also to indirect local attacks where perturbations are confined to a small image region that does not overlap with the area that we aim to fool.

teaser Detecting the Unexpected via Image Resynthesis
Krzysztof Lis, Krishna Kanth Nakka, Pascal Fua and Mathieu Salzmann
International Conference on Computer Vision (ICCV) , 2019
arXiv / code / Poster

We rely on the intuition that the network will produce spurious labels in regions depicting unexpected anomaly objects. Therefore, resynthesizing the image from the resulting semantic map will yield significant appearance differences with respect to the input image which we detect through an auxiliary network

teaser Interpretable BoW Networks for Adversarial Example Detectio
Krishna Kanth Nakka and Mathieu Salzmann
Explainable and Interpretable AI workshop, ICCV, 2018 [Oral]
arXiv / Slides

We build upon the intuition that, while adversarial samples look very similar to real images, to produce incorrect predictions, they should activate codewords with a significantly different visual representation. We therefore cast the adversarial example detection problem as that of comparing the input image with the most highly activated visual codeword.

teaser Deep Attentional Structured Representation Learning for Visual Recognition
Krishna Kanth Nakka and Mathieu Salzmann
British Media Vision Conference (BMVC), 2018
arXiv / Poster

we introduce an attentional structured representation learning framework that incorporates an image-specific attention mechanism within the aggregation process.

teaser Deep learning based fence segmentation and removal from an image using a video sequence
SankarGanesh Jonna, Krishna Kanth Nakka and Rajiv Ranjan Sahay
International Workshop on Video Segmentation, ECCV, 2016 [Oral]
arXiv / Slides

We use knowledge of spatial locations of fences to subsequently estimate occlusion-aware optical flow. We then fuse the occluded information from neighbouring frames by solving inverse problem of denoising

teaser Detection and removal of fence occlusions in an image using a video of the static/dynamic scene
SankarGanesh Jonna, Krishna Kanth Nakka and Rajiv Ranjan Sahay
Journal of the Optical Society of America A (JOSA A) , 2016
arXiv / PDF

Our approach of defencing is as follows: (i) detection of spatial locations of fences/occlusions in the frames of the video, (ii) estimation of relative motion between the observations, and (iii) data fusion to fill in occluded pixels in the reference image. We assume the de-fenced image as a Markov random field and obtain its maximum a posteriori estimate by solving the corresponding inverse problem.

teaser My camera can see through fences: A deep learning approach for image de-fencing
SankarGanesh Jonna, Krishna Kanth Nakka and Rajiv Ranjan Sahay
Asian Conference on Pattern Recognition (ACPR), , 2015
arXiv / PDF / Poster

We propose a semi-automated de-fencing algorithm using a video of the dynamic scene. The inverse problem offence removal is solved using split Bregman technique assuming total variation of the de-fenced image as the regularization constraint.


teaser 3D-to-2D mapping for user interactive segmentation of human leg muscles from MRI data
Nilanjan Ray, Satarupa Mukherjee, Krishna Kanth Nakka, Scott T. Acton, Silvia S. Blanker
Signal and Information Processing, GlobalSIP, 2014
arXiv / PDF

We proposing a framework for user interactive segmentation of MRI of human leg muscles built upon the the strategy of bootstrapping with minimal supervision.

teaser Non-uniform sampling in EPR: optimizing data acquisition for Hyscore spectroscopy
Krishna Kanth Nakka Y. A. Tesiram, I. M. Brereton, M. Mobli and J. R. Harmer
Physical Chemistry Chemical Physics (PCCP), 2014
Paper / PDF / Supp

We show through non-linear sampling scheme with maximum entropy reconstruction technique in HYSCORE, the experimental times can be shortened by approximately an order of magnitude as compared to conventional linear sampling with negligible loss of information

Scholarships

I'm deeply grateful for the generous scholarships I received throughout my academic journey. Some of these scholarships include:

Reviewer

I have peer-reviewed more than 50 articles. Some of them include:

  • Reviewer at Transactions on Pattern Analysis and Machine Intelligence, 2019, 2023
  • Reviewer at Neural Information Processing Systems, NeurIPS 2021, 2022, 2023
  • Reviewer at Computer Vision and Pattern Recognition, CVPR 2023
  • Reviewer at International Conference on Computer Vision and Pattern Recognition, ICCV 2023
  • Reviewer at International Conference on Machine Learning, ICML 2023
  • PC Member and Reviewer at New Frontiers in Machine Learning, International Conference on Machine Learning, ICML 2023
  • Reviewer at British Machine Vision Conference, BMVC 2023
  • Reviewer at Winter Application for Computer Vision Conference, WACV 2019, 2024
  • Reviewer at International Conference on Artificial Intelligence and Statistics (AISTATS) 2024
  • Reviewer at International Conference on Learning Representations, ICLR 2024
Outside research

Apart from work, I spend time with lakes. Thanks for visiting this page. I leave you with a thought that always lingers in my mind by Sirivennela gaaru:

నువ్వు తినే ప్రతి ఒక మెతుకు ఈ సంఘం పండించింది, గర్వించే ఈ నీ బ్రతుకు ఈ సమాజమే మలిచింది ...
ఋణం తీర్చు తరుణం వస్తే తప్పించుకు పోతున్నావా, తెప్ప తగలపెట్టేస్తావా ఏరు దాటగానే ...

Loosely translates to:

Every single grain you eat is made by this society, And this life of which you are so proud of, is shaped by the society, And when the time comes for a payback, Are you escaping away? Will you burn the boat once you cross the stream?

Quoting Audrey, "Nothing is more important than empathy for another human being’s suffering. Nothing—not career, not wealth, not intelligence, certainly not status. We have to feel for one another if we’re going to survive with dignity."


Credits: Webpage template from Jon Barron.