Adriana Romero Soriano

2024-12-03

TMLR (accepté)

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

Melissa Hall

Alicia Sun

Candace Ross

2024-11-21

Lecture Notes in Computer Science (publié)

Boosting Latent Diffusion with Perceptual Objectives

Tariq Berrada

Pietro Astolfi

Jakob Verbeek

Melissa Hall

Marton Havasi

Yohann Benchetrit

Karteek Alahari

Latent diffusion models (LDMs) power state-of-the-art high-resolution generative image models. LDMs learn the data distribution in the laten… (voir plus)t space of an autoencoder (AE) and produce images by mapping the generated latents into RGB image space using the AE decoder. While this approach allows for efficient model training and sampling, it induces a disconnect between the training of the diffusion model and the decoder, resulting in a loss of detail in the generated images. To remediate this disconnect, we propose to leverage the internal features of the decoder to define a latent perceptual loss (LPL). This loss encourages the models to create sharper and more realistic images. Our loss can be seamlessly integrated with common autoencoders used in latent diffusion models, and can be applied to different generative modeling paradigms such as DDPM with epsilon and velocity prediction, as well as flow matching. Extensive experiments with models trained on three datasets at 256 and 512 resolution show improved quantitative -- with boosts between 6% and 20% in FID -- and qualitative results when using our perceptual loss.

2024-11-06

ArXiv (prépublication)

Boosting Latent Diffusion with Perceptual Objectives

Tariq Berrada

Pietro Astolfi

Jakob Verbeek

Melissa Hall

Marton Havasi

Yohann Benchetrit

Karteek Alahari

Latent diffusion models (LDMs) power state-of-the-art high-resolution generative image models. LDMs learn the data distribution in the laten… (voir plus)t space of an autoencoder (AE) and produce images by mapping the generated latents into RGB image space using the AE decoder. While this approach allows for efficient model training and sampling, it induces a disconnect between the training of the diffusion model and the decoder, resulting in a loss of detail in the generated images. To remediate this disconnect, we propose to leverage the internal features of the decoder to define a latent perceptual loss (LPL). This loss encourages the models to create sharper and more realistic images. Our loss can be seamlessly integrated with common autoencoders used in latent diffusion models, and can be applied to different generative modeling paradigms such as DDPM with epsilon and velocity prediction, as well as flow matching. Extensive experiments with models trained on three datasets at 256 and 512 resolution show improved quantitative -- with boosts between 6% and 20% in FID -- and qualitative results when using our perceptual loss.

2024-11-06

ArXiv (prépublication)

On Improved Conditioning Mechanisms and Pre-training Strategies for Diffusion Models

Tariq Berrada

Pietro Astolfi

Melissa Hall

Yohann Benchetrit

Marton Havasi

Matthew J. Muckley

Karteek Alahari

Jakob Verbeek

Large-scale training of latent diffusion models (LDMs) has enabled unprecedented quality in image generation. However, the key components of… (voir plus) the best performing LDM training recipes are oftentimes not available to the research community, preventing apple-to-apple comparisons and hindering the validation of progress in the field. In this work, we perform an in-depth study of LDM training recipes focusing on the performance of models and their training efficiency. To ensure apple-to-apple comparisons, we re-implement five previously published models with their corresponding recipes. Through our study, we explore the effects of (i)~the mechanisms used to condition the generative model on semantic information (e.g., text prompt) and control metadata (e.g., crop size, random flip flag, etc.) on the model performance, and (ii)~the transfer of the representations learned on smaller and lower-resolution datasets to larger ones on the training efficiency and model performance. We then propose a novel conditioning mechanism that disentangles semantic and control metadata conditionings and sets a new state-of-the-art in class-conditional generation on the ImageNet-1k dataset -- with FID improvements of 7% on 256 and 8% on 512 resolutions -- as well as text-to-image generation on the CC12M dataset -- with FID improvements of 8% on 256 and 23% on 512 resolution.

2024-11-05

ArXiv (prépublication)

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

Pietro Astolfi

Marlene Careil

Melissa Hall

Oscar Mañas

Matthew J. Muckley

Jakob Verbeek

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.

2024-10-10

NeurIPS.cc/2024/Workshop/RBFM (présentation orale)

Controlling Multimodal LLMs via Reward-guided Decoding

Oscar Mañas

Pierluca D'Oro

Koustuv Sinha

Aishwarya Agrawal

2024-10-10

NeurIPS.cc/2024/Workshop/AFM (poster)

Deliberate Practice with Synthetic Data

Mohammad Pezeshki

Pietro Astolfi

Melissa Hall

Florian Bordes

Jakob Verbeek

2024-10-10

NeurIPS.cc/2024/Workshop/AFM (poster)

OC-CLIP : Object-centric binding in Contrastive Language-Image Pretraining

Rim Assouel

Pietro Astolfi

Florian Bordes

Recent advancements in vision-language models (VLMs) have been driven by contrastive models like CLIP which learn to associate visual inform… (voir plus)ation with their corresponding text descriptions. However, these models have limitations in understanding complex compositional scenes involving multiple objects and their spatial relationships. To address these challenges, we propose a novel approach that diverges from traditional data-centric methods of enhancing model performance with hard negatives examples. Our work instead focuses on integrating sufficient inductive biases into pre-trained CLIP-like models to improve their compositional understanding without using additional data annotations. We introduce a binding module that connects a scene graph of the text with an induced graph-like representation of the image, facilitating a structured similarity assessment. We also leverage relationships as text-conditioned visual constraints, thereby capturing the intricate interactions between objects and their contextual relationships more effectively. Our resulting model (OC-CLIP) not only enhances the performance of CLIP in multi-object compositional understanding but also paves the way for more accurate and efficient image-text matching in complex scenes.

2024-10-10

NeurIPS.cc/2024/Workshop/Compositional_Learning (poster)

On improved Conditioning Mechanisms and Pre-training Strategies for Diffusion Models

Tariq Berrada

Pietro Astolfi

Melissa Hall

Yohann Benchetrit

Marton Havasi

Matthew J. Muckley

Karteek Alahari

Jakob Verbeek

Large-scale training of latent diffusion models (LDMs) has enabled unprecedented quality in image generation. However, large-scale end-to-e… (voir plus)nd training of these models is computationally costly, and hence most research focuses either on finetuning pretrained models or experiments at smaller scales. In this work we aim to improve the training efficiency and performance of LDMs with the goal of scaling to larger datasets and higher resolutions. We focus our study on two points that are critical for good performance and efficient training: (i) the mechanisms used for semantic level (\eg a text prompt, or class name) and low-level (crop size, random flip, \etc) conditioning of the model, and (ii) pre-training strategies to transfer representations learned on smaller and lower-resolution datasets to larger ones. The main contributions of our work are the following: we present systematic experimental study of these points, we propose a novel conditioning mechanism that disentangles semantic and low-level conditioning, we obtain state-of-the-art performance on CC12M for text-to-image at 512 resolution.

2024-09-25

NeurIPS.cc/2024/Conference (poster)

What makes a good metric? Evaluating automatic metrics for text-to-image consistency

Candace Ross

Melissa Hall

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)