Portrait of Michal Drozdzal is unavailable

Michal Drozdzal

Alumni

Publications

Improved baselines for vision-language pre-training
Enrico Fini
Pietro Astolfi
Adriana Romero-Soriano
Jakob Verbeek
Contrastive learning has emerged as an efficient framework to learn multimodal representations. CLIP, a seminal work in this area, achieved … (see more)impressive results by training on paired image-text data using the contrastive loss. Recent work claims improvements over CLIP using additional non-contrastive losses inspired from self-supervised learning. However, it is sometimes hard to disentangle the contribution of these additional losses from other implementation details, e.g., data augmentation or regularization techniques, used to train the model. To shed light on this matter, in this paper, we first propose, implement and evaluate several baselines obtained by combining contrastive learning with recent advances in self-supervised learning. In particular, we use the loss functions that were proven successful for visual self-supervised learning to align image and text modalities. We find that these baselines outperform a basic implementation of CLIP. However, when a stronger training recipe is employed, the advantage disappears. Indeed, we find that a simple CLIP baseline can also be improved substantially, up to a 25% relative improvement on downstream zero-shot tasks, by using well-known training techniques that are popular in other subfields. Moreover, we discover that it is enough to apply image and text augmentations to make up for most of the improvement attained by prior works. With our improved training recipe for CLIP, we obtain state-of-the-art performance on four standard datasets, and consistently outperform prior work (up to +4% on the largest dataset), while being substantially simpler. The code is available at https://github.com/facebookresearch/clip-rocket
Controllable Image Generation via Collage Representations
Arantxa Casanova
Marlene Careil
Adriana Romero
Christopher Pal
Jakob Verbeek
Instance-Conditioned GAN Data Augmentation for Representation Learning
Pietro Astolfi
Arantxa Casanova
Jakob Verbeek
P Vincent
Adriana Romero
Learning to Substitute Ingredients in Recipes
Bahare Fatemi
Quentin Duval
Rohit Girdhar
Adriana Romero
Recipe personalization through ingredient substitution has the potential to help people meet their dietary needs and preferences, avoid pote… (see more)ntial allergens, and ease culinary exploration in everyone's kitchen. To address ingredient substitution, we build a benchmark, composed of a dataset of substitution pairs with standardized splits, evaluation metrics, and baselines. We further introduce Graph-based Ingredient Substitution Module (GISMo), a novel model that leverages the context of a recipe as well as generic ingredient relational information encoded within a graph to rank plausible substitutions. We show through comprehensive experimental validation that GISMo surpasses the best performing baseline by a large margin in terms of mean reciprocal rank. Finally, we highlight the benefits of GISMo by integrating it in an improved image-to-recipe generation pipeline, enabling recipe personalization through user intervention. Quantitative and qualitative results show the efficacy of our proposed system, paving the road towards truly personalized cooking and tasting experiences.
ImageNet-X: Understanding Model Mistakes with Factor of Variation Annotations
Badr Youbi Idrissi
Diane Bouchacourt
Randall Balestriero
Ivan Evtimov
Caner Hazirbas
P Vincent
David Lopez-Paz
Mark Ibrahim
Deep learning vision systems are widely deployed across applications where reliability is critical. However, even today's best models can fa… (see more)il to recognize an object when its pose, lighting, or background varies. While existing benchmarks surface examples challenging for models, they do not explain why such mistakes arise. To address this need, we introduce ImageNet-X—a set of sixteen human annotations of factors such as pose, background, or lighting the entire ImageNet-1k validation set as well as a random subset of 12k training images. Equipped with ImageNet-X, we investigate 2,200 current recognition models and study the types of mistakes as a function of model’s (1) architecture, e.g. transformer vs. convolutional, (2) learning paradigm, e.g. supervised vs. self-supervised, and (3) training procedures, e.g., data augmentation. Regardless of these choices, we find models have consistent failure modes across ImageNet-X categories. We also find that while data augmentation can improve robustness to certain factors, they induce spill-over effects to other factors. For example, color-jitter augmentation improves robustness to color and brightness, but surprisingly hurts robustness to pose. Together, these insights suggest to advance the robustness of modern vision models, future research should focus on collecting additional data and understanding data augmentation schemes. Along with these insights, we release a toolkit based on ImageNet-X to spur further study into the mistakes image recognition systems make.
The Liver Tumor Segmentation Benchmark (LiTS)
Patrick Bilic
Patrick Christ
Hongwei Bran Li
Grzegorz Chlebus
Hao Chen
Qi Dou
Chi-Wing Fu
Xu Han
Gabriel Efrain Humpire Mamani
Pheng Ann Heng
Jürgen Hesser
Samuel Kadoury
Julian Walter Holch
Tomasz Konopczynski
Miao Yue
Chunming Li
X. Li
Jana Lipková
John Lowengrub … (see 99 more)
Michal Marianne Amitai
Hans Meine
J. Moltz
Christopher Pal
Marie Piraud
Ivan Ezhov
Xiaojuan Qi
Fernando Navarro
Jin Qi
Florian Kofler
Markus Rempfler
Johannes C. Paetzold
Suprosanna Shit
Andrea Schenk
Xiaobin Hu
Anjany Sekuboyina
Ping Zhou
Christian Hülsemeyer
Marcel Beetz
Jan Kirschke
Florian Ettlinger
Felix Gruen
Benedikt Wiestler
Zhiheng Zhang
Georgios Kaissis
Fabian Lohöfer
Rickmer Braren
J. Holch
Michela Antonelli
Felix Hofmann
Woong Bae
Wieland Sommer
Míriam Bellver
Volker Heinemann
Lei Bi
Colin Jacobs
G. Mamani
Bram van Ginneken
Erik B. Dam
Gabriel Chartrand
An Tang
Bogdan Georgescu
Avi Ben-Cohen
Xavier Giró-i-Nieto
Eyal Klang
M. Amitai
E. Konen
Hayit Greenspan
Johan Moreau
Jan Hendrik Moltz
Alexandre Hostettler
Christian Igel
Luc Soler
Fabian Isensee
Refael Vivanti
Paul Jäger
Adi Szeskin
Fucang Jia
Naama Lev-Cohain
Krishna Chaitanya Kaluva
Jacob Sosna
Mahendra Khened
Leo Joskowicz
Ildoo Kim
Bjoern Menze
Jae-Hun Kim
Zengming Shen
Sungwoong Kim
Simon Kohl
Avinash Kori
Ganapathy Krishnamurthi
Fan Li
Hongchao Li
Junbo Li
Xiaomeng Li
Jun Ma
Klaus Maier-Hein
Kevis-Kokitsi Maninis
Dorit Merhof
Akshay Pai
Mathias Perslev
Jens Petersen
Jordi Pont-Tuset
Oliver Rippel
Ignacio Sarasua
Jordi Torres
Christian Wachinger
Chunliang Wang
Leon Weninger
Jianrong Wu
Daguang Xu
Xiaoping Yang
Simon Chun-Ho Yu
Yading Yuan
Liping Zhang
Jorge Cardoso
Spyridon Bakas
Uncertainty-Driven Active Vision for Implicit Scene Reconstruction
Edward J. Smith
D. Nowrouzezahrai
Adriana Romero
Active 3D Shape Reconstruction from Vision and Touch
Edward J. Smith
Luis Pineda
Roberto Calandra
Jitendra Malik
Adriana Romero
Humans build 3D understandings of the world through active object exploration, using jointly their senses of vision and touch. However, in 3… (see more)D shape reconstruction, most recent progress has relied on static datasets of limited sensory data such as RGB images, depth maps or haptic readings, leaving the active exploration of the shape largely unexplored. In active touch sensing for 3D reconstruction, the goal is to actively select the tactile readings that maximize the improvement in shape reconstruction accuracy. However, the development of deep learning-based active touch models is largely limited by the lack of frameworks for shape exploration. In this paper, we focus on this problem and introduce a system composed of: 1) a haptic simulator leveraging high spatial resolution vision-based tactile sensors for active touching of 3D objects; 2) a mesh-based 3D shape reconstruction model that relies on tactile or visuotactile signals; and 3) a set of data-driven solutions with either tactile or visuotactile priors to guide the shape exploration. Our framework enables the development of the first fully data-driven solutions to active touch on top of learned models for object understanding. Our experiments show the benefits of such solutions in the task of 3D shape understanding where our models consistently outperform natural baselines. We provide our framework as a tool to foster future research in this direction.
3D Shape Reconstruction from Vision and Touch
Edward J. Smith
Roberto Calandra
Adriana Romero
Georgia Gkioxari
Jitendra Malik
When a toddler is presented a new toy, their instinctual behaviour is to pick it up and inspect it with their hand and eyes in tandem, clear… (see more)ly searching over its surface to properly understand what they are playing with. Here, touch provides high fidelity localized information while vision provides complementary global context. However, in 3D shape reconstruction, the complementary fusion of visual and haptic modalities remains largely unexplored. In this paper, we study this problem and present an effective chart-based approach to fusing vision and touch, which leverages advances in graph convolutional networks. To do so, we introduce a dataset of simulated touch and vision signals from the interaction between a robotic hand and a large array of 3D objects. Our results show that (1) leveraging both vision and touch signals consistently improves single-modality baselines; (2) our approach outperforms alternative modality fusion methods and strongly benefits from the proposed chart-based structure; (3) the reconstruction quality increases with the number of grasps provided; and (4) the touch information not only enhances the reconstruction at the touch site but also extrapolates to its local neighborhood.
On the Iterative Refinement of Densely Connected Representation Levels for Semantic Segmentation
Arantxa Casanova
Guillem Cucurull
Adriana Romero
State-of-the-art semantic segmentation approaches increase the receptive field of their models by using either a downsampling path composed … (see more)of poolings/strided convolutions or successive dilated convolutions. However, it is not clear which operation leads to best results. In this paper, we systematically study the differences introduced by distinct receptive field enlargement methods and their impact on the performance of a novel architecture, called Fully Convolutional DenseResNet (FC-DRN). FC-DRN has a densely connected backbone composed of residual networks. Following standard image segmentation architectures, receptive field enlargement operations that change the representation level are interleaved among residual networks. This allows the model to exploit the benefits of both residual and dense connectivity patterns, namely: gradient flow, iterative refinement of representations, multi-scale feature combination and deep supervision. In order to highlight the potential of our model, we test it on the challenging CamVid urban scene understanding benchmark and make the following observations: 1) downsampling operations outperform dilations when the model is trained from scratch, 2) dilations are useful during the finetuning step of the model, 3) coarser representations require less refinement steps, and 4) ResNets (by model construction) are good regularizers, since they can reduce the model capacity when needed. Finally, we compare our architecture to alternative methods and report state-of-the-art result on the Camvid dataset, with at least twice fewer parameters.
Convolutional neural networks for mesh-based parcellation of the cerebral cortex
Guillem Cucurull
Konrad Wagstyl
Arantxa Casanova
Estrid Jakobsen
Adriana Romero
Alan C. Evans
In order to understand the organization of the cerebral cortex, it is necessary to create a map or parcellation of cortical areas. Reconstru… (see more)ctions of the cortical surface created from structural MRI scans, are frequently used in neuroimaging as a common coordinate space for representing multimodal neuroimaging data. These meshes are used to investigate healthy brain organization as well as abnormalities in neurological and psychiatric conditions. We frame cerebral cortex parcellation as a mesh segmentation task, and address it by taking advantage of recent advances in generalizing convolutions to the graph domain. In particular, we propose to assess graph convolutional networks and graph attention networks, which, in contrast to previous mesh parcellation models, exploit the underlying structure of the data to make predictions. We show experimentally on the Human Connectome Project dataset that the proposed graph convolutional models outperform current state-of-the-art and baselines, highlighting the potential and applicability of these methods to tackle neuroimaging challenges, paving the road towards a better characterization of brain diseases.
Learning Normalized Inputs for Iterative Estimation in Medical Image Segmentation
Gabriel Chartrand
Lisa Di Jorio
An Tang
Adriana Romero
Samuel Kadoury
In this paper, we introduce a simple, yet powerful pipeline for medical image segmentation that combines Fully Convolutional Networks (FCNs)… (see more) with Fully Convolutional Residual Networks (FC-ResNets). We propose and examine a design that takes particular advantage of recent advances in the understanding of both Convolutional Neural Networks as well as ResNets. Our approach focuses upon the importance of a trainable pre-processing when using FC-ResNets and we show that a low-capacity FCN model can serve as a pre-processor to normalize medical input data. In our image segmentation pipeline, we use FCNs to obtain normalized images, which are then iteratively refined by means of a FC-ResNet to generate a segmentation prediction. As in other fully convolutional approaches, our pipeline can be used off-the-shelf on different image modalities. We show that using this pipeline, we exhibit state-of-the-art performance on the challenging Electron Microscopy benchmark, when compared to other 2D methods. We improve segmentation results on CT images of liver lesions, when contrasting with standard FCN methods. Moreover, when applying our 2D pipeline on a challenging 3D MRI prostate segmentation challenge we reach results that are competitive even when compared to 3D methods. The obtained results illustrate the strong potential and versatility of the pipeline by achieving highly accurate results on multi-modality images from different anatomical regions and organs.