AltGen: AI-Driven Alt Text Generation for Enhancing EPUB Accessibility

TL;DR

AltGen is an AI-powered pipeline that automates the generation of descriptive alt text for images in EPUB files, significantly improving accessibility for visually impaired users through advanced generative models and multimodal analysis.

Contribution

This paper introduces AltGen, a novel AI-driven system that combines computer vision and language models to automatically produce high-quality alt text for EPUB images, enhancing accessibility at scale.

Findings

Achieved 97.5% reduction in accessibility errors.

Outperformed existing methods in accuracy and relevance.

Received positive user feedback on usability improvements.

Abstract

Digital accessibility is a cornerstone of inclusive content delivery, yet many EPUB files fail to meet fundamental accessibility standards, particularly in providing descriptive alt text for images. Alt text plays a critical role in enabling visually impaired users to understand visual content through assistive technologies. However, generating high-quality alt text at scale is a resource-intensive process, creating significant challenges for organizations aiming to ensure accessibility compliance. This paper introduces AltGen, a novel AI-driven pipeline designed to automate the generation of alt text for images in EPUB files. By integrating state-of-the-art generative models, including advanced transformer-based architectures, AltGen achieves contextually relevant and linguistically coherent alt text descriptions. The pipeline encompasses multiple stages, starting with data preprocessing to extract and prepare relevant content, followed by visual analysis using computer vision models such as CLIP and ViT. The extracted visual features are enriched with contextual information from surrounding text, enabling the fine-tuned language models to generate descriptive and accurate alt text. Validation of the generated output employs both quantitative metrics, such as cosine similarity and BLEU scores, and qualitative feedback from visually impaired users. Experimental results demonstrate the efficacy of AltGen across diverse datasets, achieving a 97.5% reduction in accessibility errors and high scores in similarity and linguistic fidelity metrics. User studies highlight the practical impact of AltGen, with participants reporting significant improvements in document usability and comprehension. Furthermore, comparative analyses reveal that AltGen outperforms existing approaches in terms of accuracy, relevance, and scalability.