Automated Image Color Mapping for a Historic Photographic Collection

In the 1970s, the United States Environmental Protection Agency sponsored Documerica, a large-scale photography initiative to document environmental subjects nation-wide. While over 15,000 digitized public-domain photographs from the collection are available online, most of the images were scanned from damaged copies of the original prints. We present and evaluate a modified histogram matching technique based on the underlying chemistry of the prints for correcting the damaged images by using training data collected from a small set of undamaged prints. The entire set of color-adjusted Documerica images is made available in an open repository.

Explainable Search and Discovery of Visual Cultural Heritage Collections with Multimodal Large Language Models

Many cultural institutions have made large digitized visual collections available online, often under permissible re-use licences. Creating interfaces for exploring and searching these collections is difficult, particularly in the absence of granular metadata. In this paper, we introduce a method for using state-of-the-art multimodal large language models (LLMs) to enable an open-ended, explainable search and discovery interface for visual collections. We show how our approach can create novel clustering and recommendation systems that avoid common pitfalls of methods based directly on visual embeddings. Of particular interest is the ability to offer concrete textual explanations of each recommendation without the need to preselect the features of interest. Together, these features can create a digital interface that is more open-ended and flexible while also being better suited to addressing privacy and ethical concerns. Through a case study using a collection of documentary photographs, we provide several metrics showing the efficacy and possibilities of our approach.

Cross-Discourse and Multilingual Exploration of Textual Corpora with the DualNeighbors Algorithm

Word choice is dependent on the cultural context of writers and their subjects. Different words are used to describe similar actions, objects, and features based on factors such as class, race, gender, geography and political affinity. Exploratory techniques based on locating and counting words may, therefore, lead to conclusions that reinforce culturally inflected boundaries. We offer a new method, the DualNeighbors algorithm, for linking thematically similar documents both within and across discursive and linguistic barriers to reveal cross-cultural connections. Qualitative and quantitative evaluations of this technique are shown as applied to two cultural datasets of interest to researchers across the humanities and social sciences. An open-source implementation of the DualNeighbors algorithm is provided to assist in its application.