PopAlign: Population-Level Alignment for Fair Text-to-Image Generation

Fuente: arXiv
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Main Authors: Li, Shufan, Singh, Harkanwar, Grover, Aditya
Format: Preprint
Published: 2024
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author Li, Shufan
Singh, Harkanwar
Grover, Aditya
author_facet Li, Shufan
Singh, Harkanwar
Grover, Aditya
contents Text-to-image (T2I) models achieve high-fidelity generation through extensive training on large datasets. However, these models may unintentionally pick up undesirable biases of their training data, such as over-representation of particular identities in gender or ethnicity neutral prompts. Existing alignment methods such as Reinforcement Learning from Human Feedback (RLHF) and Direct Preference Optimization (DPO) fail to address this problem effectively because they operate on pairwise preferences consisting of individual samples, while the aforementioned biases can only be measured at a population level. For example, a single sample for the prompt "doctor" could be male or female, but a model generating predominantly male doctors even with repeated sampling reflects a gender bias. To address this limitation, we introduce PopAlign, a novel approach for population-level preference optimization, while standard optimization would prefer entire sets of samples over others. We further derive a stochastic lower bound that directly optimizes for individual samples from preferred populations over others for scalable training. Using human evaluation and standard image quality and bias metrics, we show that PopAlign significantly mitigates the bias of pretrained T2I models while largely preserving the generation quality. Code is available at https://github.com/jacklishufan/PopAlignSDXL.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19668
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle PopAlign: Population-Level Alignment for Fair Text-to-Image Generation
Li, Shufan
Singh, Harkanwar
Grover, Aditya
Computer Vision and Pattern Recognition
Text-to-image (T2I) models achieve high-fidelity generation through extensive training on large datasets. However, these models may unintentionally pick up undesirable biases of their training data, such as over-representation of particular identities in gender or ethnicity neutral prompts. Existing alignment methods such as Reinforcement Learning from Human Feedback (RLHF) and Direct Preference Optimization (DPO) fail to address this problem effectively because they operate on pairwise preferences consisting of individual samples, while the aforementioned biases can only be measured at a population level. For example, a single sample for the prompt "doctor" could be male or female, but a model generating predominantly male doctors even with repeated sampling reflects a gender bias. To address this limitation, we introduce PopAlign, a novel approach for population-level preference optimization, while standard optimization would prefer entire sets of samples over others. We further derive a stochastic lower bound that directly optimizes for individual samples from preferred populations over others for scalable training. Using human evaluation and standard image quality and bias metrics, we show that PopAlign significantly mitigates the bias of pretrained T2I models while largely preserving the generation quality. Code is available at https://github.com/jacklishufan/PopAlignSDXL.
title PopAlign: Population-Level Alignment for Fair Text-to-Image Generation
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2406.19668