Adriana Romero Soriano

Adina Williams

2024-07-10

colmweb.org/COLM/2024/Conference (accepté)

Decomposed evaluations of geographic disparities in text-to-image models

Abhishek Sureddy

Dishant Padalia

Nandhinee Periyakaruppan

Oindrila Saha

Adina Williams

Megan Richards

Polina Kirichenko

Melissa Hall

2024-06-28

ICML.cc/2024/Workshop/NextGenAISafety (poster)

A Picture is Worth More Than 77 Text Tokens: Evaluating CLIP-Style Models on Dense Captions

Jack Urbanek

Florian Bordes

Pietro Astolfi

Mary Williamson

Vasu Sharma

2024-06-16

2024 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) (publié)

Consistency-diversity-realism Pareto fronts of conditional image generative models

Pietro Astolfi

Marlene Careil

Melissa Hall

Oscar Mañas

Matthew Muckley

Jakob Verbeek

Michal Drozdzal

Building world models that accurately and comprehensively represent the real world is the utmost aspiration for conditional image generative… (voir plus) models as it would enable their use as world simulators. For these models to be successful world models, they should not only excel at image quality and prompt-image consistency but also ensure high representation diversity. However, current research in generative models mostly focuses on creative applications that are predominantly concerned with human preferences of image quality and aesthetics. We note that generative models have inference time mechanisms - or knobs - that allow the control of generation consistency, quality, and diversity. In this paper, we use state-of-the-art text-to-image and image-and-text-to-image models and their knobs to draw consistency-diversity-realism Pareto fronts that provide a holistic view on consistency-diversity-realism multi-objective. Our experiments suggest that realism and consistency can both be improved simultaneously; however there exists a clear tradeoff between realism/consistency and diversity. By looking at Pareto optimal points, we note that earlier models are better at representation diversity and worse in consistency/realism, and more recent models excel in consistency/realism while decreasing significantly the representation diversity. By computing Pareto fronts on a geodiverse dataset, we find that the first version of latent diffusion models tends to perform better than more recent models in all axes of evaluation, and there exist pronounced consistency-diversity-realism disparities between geographical regions. Overall, our analysis clearly shows that there is no best model and the choice of model should be determined by the downstream application. With this analysis, we invite the research community to consider Pareto fronts as an analytical tool to measure progress towards world models.

2024-06-14

ArXiv (prépublication)

Improving Geo-diversity of Generated Images with Contextualized Vendi Score Guidance

Reyhane Askari Hemmat

Melissa Hall

Alicia Sun

Candace Ross

Michal Drozdzal

2024-06-06

ArXiv (prépublication)

Towards Geographic Inclusion in the Evaluation of Text-to-Image Models

Melissa Hall

Samuel J. Bell

Candace Ross

Adina Williams

Michal Drozdzal

Rapid progress in text-to-image generative models coupled with their deployment for visual content creation has magnified the importance of … (voir plus)thoroughly evaluating their performance and identifying potential biases. In pursuit of models that generate images that are realistic, diverse, visually appealing, and consistent with the given prompt, researchers and practitioners often turn to automated metrics to facilitate scalable and cost-effective performance profiling. However, commonly-used metrics often fail to account for the full diversity of human preference; often even in-depth human evaluations face challenges with subjectivity, especially as interpretations of evaluation criteria vary across regions and cultures. In this work, we conduct a large, cross-cultural study to study how much annotators in Africa, Europe, and Southeast Asia vary in their perception of geographic representation, visual appeal, and consistency in real and generated images from state-of-the art public APIs. We collect over 65,000 image annotations and 20 survey responses. We contrast human annotations with common automated metrics, finding that human preferences vary notably across geographic location and that current metrics do not fully account for this diversity. For example, annotators in different locations often disagree on whether exaggerated, stereotypical depictions of a region are considered geographically representative. In addition, the utility of automatic evaluations is dependent on assumptions about their set-up, such as the alignment of feature extractors with human perception of object similarity or the definition of"appeal"captured in reference datasets used to ground evaluations. We recommend steps for improved automatic and human evaluations.

2024-06-05

The 2024 ACM Conference on Fairness, Accountability, and Transparency (publié)

Improving Text-to-Image Consistency via Automatic Prompt Optimization

Oscar Mañas

Pietro Astolfi

Melissa Hall

Candace Ross

Jack Urbanek

Adina Williams

Aishwarya Agrawal

Michal Drozdzal

2024-03-26

ArXiv (prépublication)

DP-RDM: Adapting Diffusion Models to Private Domains Without Fine-Tuning

Jonathan Lebensold

Maziar Sanjabi

Pietro Astolfi

Kamalika Chaudhuri

Mike Rabbat

Chuan Guo

2024-03-21

ArXiv (prépublication)

GPS-SSL: Guided Positive Sampling to Inject Prior Into Self-Supervised Learning

Aarash Feizi

Randall Balestriero

Arantxa Casanova

Reihaneh Rabbany

We propose Guided Positive Sampling Self-Supervised Learning (GPS-SSL), a general method to inject a priori knowledge into Self-Supervised L… (voir plus)earning (SSL) positive samples selection. Current SSL methods leverage Data-Augmentations (DA) for generating positive samples and incorporate prior knowledge - an incorrect, or too weak DA will drastically reduce the quality of the learned representation. GPS-SSL proposes instead to design a metric space where Euclidean distances become a meaningful proxy for semantic relationship. In that space, it is now possible to generate positive samples from nearest neighbor sampling. Any prior knowledge can now be embedded into that metric space independently from the employed DA. From its simplicity, GPS-SSL is applicable to any SSL method, e.g. SimCLR or BYOL. A key benefit of GPS-SSL is in reducing the pressure in tailoring strong DAs. For example GPS-SSL reaches 85.58% on Cifar10 with weak DA while the baseline only reaches 37.51%. We therefore move a step forward towards the goal of making SSL less reliant on DA. We also show that even when using strong DAs, GPS-SSL outperforms the baselines on under-studied domains. We evaluate GPS-SSL along with multiple baseline SSL methods on numerous downstream datasets from different domains when the models use strong or minimal data augmentations. We hope that GPS-SSL will open new avenues in studying how to inject a priori knowledge into SSL in a principled manner.

2024-01-03

ArXiv (prépublication)

DIG In: Evaluating Disparities in Image Generations with Indicators for Geographic Diversity

Melissa Hall

Candace Ross

Adina Williams

Nicolas Carion

Michal Drozdzal

The unprecedented photorealistic results achieved by recent text-to-image generative systems and their increasing use as plug-and-play conte… (voir plus)nt creation solutions make it crucial to understand their potential biases. In this work, we introduce three indicators to evaluate the realism, diversity and prompt-generation consistency of text-to-image generative systems when prompted to generate objects from across the world. Our indicators complement qualitative analysis of the broader impact of such systems by enabling automatic and efficient benchmarking of geographic disparities, an important step towards building responsible visual content creation systems. We use our proposed indicators to analyze potential geographic biases in state-of-the-art visual content creation systems and find that: (1) models have less realism and diversity of generations when prompting for Africa and West Asia than Europe, (2) prompting with geographic information comes at a cost to prompt-consistency and diversity of generated images, and (3) models exhibit more region-level disparities for some objects than others. Perhaps most interestingly, our indicators suggest that progress in image generation quality has come at the cost of real-world geographic representation. Our comprehensive evaluation constitutes a crucial step towards ensuring a positive experience of visual content creation for everyone. Code is available at https://github.com/facebookresearch/DIG-In/.

2024-01-02

TMLR (accepté)

Feedback-guided Data Synthesis for Imbalanced Classification

Reyhane Askari Hemmat

Mohammad Pezeshki

Florian Bordes

Michal Drozdzal

Current status quo in machine learning is to use static datasets of real images for training, which often come from long-tailed distribution… (voir plus)s. With the recent advances in generative models, researchers have started augmenting these static datasets with synthetic data, reporting moderate performance improvements on classification tasks. We hypothesize that these performance gains are limited by the lack of feedback from the classifier to the generative model, which would promote the usefulness of the generated samples to improve the classifier's performance. In this work, we introduce a framework for augmenting static datasets with useful synthetic samples, which leverages one-shot feedback from the classifier to drive the sampling of the generative model. In order for the framework to be effective, we find that the samples must be close to the support of the real data of the task at hand, and be sufficiently diverse. We validate three feedback criteria on a long-tailed dataset (ImageNet-LT) as well as a group-imbalanced dataset (NICO++). On ImageNet-LT, we achieve state-of-the-art results, with over 4 percent improvement on underrepresented classes while being twice efficient in terms of the number of generated synthetic samples. NICO++ also enjoys marked boosts of over 5 percent in worst group accuracy. With these results, our framework paves the path towards effectively leveraging state-of-the-art text-to-image models as data sources that can be queried to improve downstream applications.

2023-10-30

NeurIPS.cc/2023/Workshop/SyntheticData4ML (poster)

Improved baselines for vision-language pre-training

Enrico Fini

Pietro Astolfi

Jakob Verbeek

Michal Drozdzal

2023-10-05

TMLR (accepté)