Bias Begets Bias: The Impact of Biased Embeddings on Diffusion Models

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kuchlous, Sahil, Li, Marvin, Wang, Jeffrey G.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912028970450944
author Kuchlous, Sahil
Li, Marvin
Wang, Jeffrey G.
author_facet Kuchlous, Sahil
Li, Marvin
Wang, Jeffrey G.
contents With the growing adoption of Text-to-Image (TTI) systems, the social biases of these models have come under increased scrutiny. Herein we conduct a systematic investigation of one such source of bias for diffusion models: embedding spaces. First, because traditional classifier-based fairness definitions require true labels not present in generative modeling, we propose statistical group fairness criteria based on a model's internal representation of the world. Using these definitions, we demonstrate theoretically and empirically that an unbiased text embedding space for input prompts is a necessary condition for representationally balanced diffusion models, meaning the distribution of generated images satisfy diversity requirements with respect to protected attributes. Next, we investigate the impact of biased embeddings on evaluating the alignment between generated images and prompts, a process which is commonly used to assess diffusion models. We find that biased multimodal embeddings like CLIP can result in lower alignment scores for representationally balanced TTI models, thus rewarding unfair behavior. Finally, we develop a theoretical framework through which biases in alignment evaluation can be studied and propose bias mitigation methods. By specifically adapting the perspective of embedding spaces, we establish new fairness conditions for diffusion model development and evaluation.
format Preprint
id arxiv_https___arxiv_org_abs_2409_09569
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Bias Begets Bias: The Impact of Biased Embeddings on Diffusion Models
Kuchlous, Sahil
Li, Marvin
Wang, Jeffrey G.
Machine Learning
Computer Vision and Pattern Recognition
Computers and Society
I.2.10
With the growing adoption of Text-to-Image (TTI) systems, the social biases of these models have come under increased scrutiny. Herein we conduct a systematic investigation of one such source of bias for diffusion models: embedding spaces. First, because traditional classifier-based fairness definitions require true labels not present in generative modeling, we propose statistical group fairness criteria based on a model's internal representation of the world. Using these definitions, we demonstrate theoretically and empirically that an unbiased text embedding space for input prompts is a necessary condition for representationally balanced diffusion models, meaning the distribution of generated images satisfy diversity requirements with respect to protected attributes. Next, we investigate the impact of biased embeddings on evaluating the alignment between generated images and prompts, a process which is commonly used to assess diffusion models. We find that biased multimodal embeddings like CLIP can result in lower alignment scores for representationally balanced TTI models, thus rewarding unfair behavior. Finally, we develop a theoretical framework through which biases in alignment evaluation can be studied and propose bias mitigation methods. By specifically adapting the perspective of embedding spaces, we establish new fairness conditions for diffusion model development and evaluation.
title Bias Begets Bias: The Impact of Biased Embeddings on Diffusion Models
topic Machine Learning
Computer Vision and Pattern Recognition
Computers and Society
I.2.10
url https://arxiv.org/abs/2409.09569