woodcuts

Automating Iconclass: LLMs and RAG for LargeScale Classification of Religious Woodcuts

Automating Iconclass: LLMs and RAG for LargeScale Classification of Religious Woodcuts

Written By: Drew B. Thomas

Abstract: This article presents a novel methodology for classifying early modern religious images by using Large Language Models (LLMs) and vector databases in combination with Retrieval-Augmented Generation (RAG). The approach leverages the full-page context of book illustrations from the Holy Roman Empire, allowing the LLM to generate detailed descriptions that incorporate both visual and textual elements. These descriptions are then matched to relevant Iconclass codes through a hybrid vector search. This method achieves 87% and 92% precision at five and four levels of classification, significantly outperforming traditional image and keyword-based searches. By employing full-page descriptions and RAG, the system enhances classification accuracy, offering a powerful tool for large-scale analysis of early modern visual archives. This interdisciplinary approach demonstrates the growing potential of LLMs and RAG in advancing research within art history and digital humanities.

 

Keywords: book history, protestant reformation, computer vision, digital humanities, iconclass, large-language models, vector database, semantic search, retrieval-augmented generation, information retrieval, early modern Europe, woodcuts, printing press, Martin Luther, bible illustrations