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Achieving Up to 7.6x Faster Image Delivery by Optimizing Cantaloupe IIIF Server Cache

Achieving Up to 7.6x Faster Image Delivery by Optimizing Cantaloupe IIIF Server Cache

Introduction I run Cantaloupe, an IIIF-compliant image server, in a Docker environment with S3 as the image source. IIIF viewers (such as Mirador and OpenSeadragon) generate dozens to hundreds of simultaneous tile requests every time the user zooms or pans. By reviewing the cache settings and tuning parameters, I was able to speed up tile delivery by up to 7.6x. In this article, I share the methods and results. Environment Server: AWS EC2 (2 vCPU, 7.6GB RAM) Cantaloupe: islandora/cantaloupe:2.0.10 (based on Cantaloupe 5.0.7) Image Source: Amazon S3 (S3Source) Test Image: 25167×12483px TIFF (512×512 tiles) Reverse Proxy: Traefik v3.2 Setup: Docker Compose Problem: Cache Is Disabled by Default After investigating the default settings of the islandora/cantaloupe image, I found the following state: ...

March 18, 2026 · 5 min · Nakamura
Why Contentful's Publish Button Is Greyed Out — A Locale Configuration Pitfall

Why Contentful's Publish Button Is Greyed Out — A Locale Configuration Pitfall

Introduction While building a multilingual site with Contentful, a content editor reported that the Publish button remained greyed out when creating new pages. Existing pages could be updated without issue — only new entries were affected. This article walks through the debugging process and the fix. Environment Contentful (headless CMS) Locales: Japanese (ja, default) + English (en) Next.js + Contentful Delivery API for the frontend Symptoms Creating a new Page entry and filling in all fields still leaves the Publish button greyed out Updating existing pages (editing title or body) works fine Saving as Draft works normally Narrowing Down the Cause 1. Check Content Type Validation First, I reviewed the field definitions for the page content type. ...

March 17, 2026 · 4 min · Nakamura
Fixing 6 GitHub Issues in Parallel with Claude Code: Worktrees and Agents

Fixing 6 GitHub Issues in Parallel with Claude Code: Worktrees and Agents

Introduction We develop a web-based viewer for historical sources structured in TEI/XML, built with Nuxt 2 + Vue 2 + Vuetify. This article describes how we used Claude Code’s worktree and agent features to address 6 GitHub Issues in parallel. Issues Addressed Group Count Description Priority A 3 Text viewer: nested element display bugs High B 1 Legend page: indentation not reflected Medium C 1 Analytics page: broken links High D 1 Keyword search crash High Approach: Worktrees × Parallel Agents Claude Code can run multiple agents in parallel, each in an isolated git worktree. We grouped the issues into 4 categories and launched 4 agents simultaneously. ...

March 17, 2026 · 5 min · Nakamura
Improving Google Search Console Indexing Issues with schema.org Structured Data

Improving Google Search Console Indexing Issues with schema.org Structured Data

Introduction While developing Digital Literary Map of Japan, a bilingual (Japanese/English) database of literary places in classical Japanese literature, Google Search Console reported 391 pages as “Crawled - currently not indexed.” Google was visiting these pages but choosing not to include them in its index. Why? One key measure we took was implementing schema.org structured data. In this post, I’ll explain what structured data is, how we implemented it, and what improvements we expect. ...

March 17, 2026 · 6 min · Nakamura
CATMA: A Guide to Web-Based Text Annotation and Analysis

CATMA: A Guide to Web-Based Text Annotation and Analysis

Introduction In Digital Humanities (DH) research, text analysis is one of the most fundamental and important methodologies. Conducting structural analysis of literary works and historical documents requires an environment where you can systematically annotate texts and analyze them quantitatively. CATMA (Computer Assisted Text Markup and Analysis) is a web-based text annotation and analysis platform developed by forTextLab at the University of Hamburg. It allows researchers to tag texts and perform analysis through an intuitive interface, without requiring any programming knowledge. ...

March 15, 2026 · 3 min · Nakamura
Datawrapper: A Data Visualization Tool for Researchers and Journalists

Datawrapper: A Data Visualization Tool for Researchers and Journalists

Introduction In Digital Humanities (DH) research, data visualization is an essential means of communicating analytical results. However, sophisticated visualization using tools like D3.js or Python’s Matplotlib requires programming knowledge. Datawrapper is a tool that lets you create professional charts, maps, and tables without any coding. It primarily targets journalists and researchers and is used by major media outlets such as The Washington Post and The Guardian. Key Features of Datawrapper 20+ Chart Types Datawrapper supports a wide range of visualization formats, from basic charts like bar graphs, line charts, and scatter plots to donut charts, area charts, and range plots. You can choose the optimal representation method to match the nature of your data. ...

March 15, 2026 · 3 min · Nakamura
Flourish: An Interactive Data Storytelling Platform

Flourish: An Interactive Data Storytelling Platform

Introduction Data visualization is a powerful means of communicating information. However, static charts alone sometimes struggle to effectively convey temporal changes or complex stories. Flourish is a platform that enables data storytelling through animation and interaction. It makes it easy to create dynamic visualizations such as race charts (bar chart races) and animated maps. It is used by organizations including BBC, Google, and the World Bank, and offers a free plan. ...

March 15, 2026 · 3 min · Nakamura
FromThePage: Crowdsourcing Transcription for Historical Documents

FromThePage: Crowdsourcing Transcription for Historical Documents

Introduction FromThePage is a web platform specialized for crowdsourced transcription of historical documents. It enables efficient management of the process of converting handwritten manuscripts and printed materials into text data with the help of volunteers. Adopted by libraries, museums, and archives worldwide—including the Library of Congress and the Smithsonian Institution—FromThePage has become a core tool for document digitization in Digital Humanities (DH). Key Features of FromThePage Crowdsourced Transcription The defining feature of FromThePage is the ability to conduct large-scale transcription projects through crowdsourcing. ...

March 15, 2026 · 3 min · Nakamura
Gephi Lite: Browser-Based Network Visualization for Digital Humanities

Gephi Lite: Browser-Based Network Visualization for Digital Humanities

TL;DR Gephi Lite is the browser version of Gephi, the renowned network visualization tool. Without any installation, you can load GEXF files and perform ForceAtlas2 layout, community detection, and various statistical calculations. It is ideal for network analysis commonly encountered in DH research — personal relationships, citation networks, co-occurrence networks, and more. What is Gephi Lite? Gephi is an open-source network visualization and analysis software released in 2008, often called the “Photoshop of networks” due to its widespread adoption. Gephi Lite is its browser-based version, enabling network analysis without installing a desktop application. ...

March 15, 2026 · 3 min · Nakamura
Hypothes.is: An Open-Source Web Annotation Tool Compliant with W3C Standards

Hypothes.is: An Open-Source Web Annotation Tool Compliant with W3C Standards

Introduction Close reading and annotation of texts are fundamental practices in humanities research. In the digital age, tools are needed to realize these practices in the context of the web. Hypothes.is is an open-source annotation tool that enables highlights and comments on any web page. It complies with the W3C Web Annotation standard and is used across a wide range of fields including education, research, and journalism. It is released under the BSD license. ...

March 15, 2026 · 3 min · Nakamura
Internet Archive: Leveraging the World's Largest Digital Archive

Internet Archive: Leveraging the World's Largest Digital Archive

Introduction Internet Archive is the world’s largest digital archive, operated by a non-profit organization founded by Brewster Kahle in 1996. With its mission of “Universal Access to All Knowledge,” it provides free access to billions of digital items, including web pages, books, audio, video, and software. For Digital Humanities (DH) researchers, Internet Archive serves as a critical infrastructure supporting diverse research activities—from accessing primary sources and analyzing the historical evolution of the web to building large-scale text corpora. ...

March 15, 2026 · 3 min · Nakamura
Kepler.gl: An Open-Source Tool for Beautiful Large-Scale Geospatial Data Visualization

Kepler.gl: An Open-Source Tool for Beautiful Large-Scale Geospatial Data Visualization

Introduction Geospatial data visualization is a crucial methodology in Digital Humanities (DH) research. Visually representing spatial information — such as the distribution of historical events, locations of cultural heritage sites, and demographic transitions — can yield new insights. This article introduces Kepler.gl, an open-source geospatial data visualization tool developed by Uber. What is Kepler.gl? Kepler.gl is a web-based tool designed for intuitive and visually stunning visualization of large-scale geospatial datasets. It was open-sourced in 2018 by Uber’s visualization team and is available under the MIT License, making it free to use and modify. ...

March 15, 2026 · 3 min · Nakamura
Mirador: The Optimal Open-Source Viewer for IIIF Image Comparison and Analysis

Mirador: The Optimal Open-Source Viewer for IIIF Image Comparison and Analysis

Introduction In Digital Humanities research, comparing and examining multiple materials side by side is a common practice. A high-performance image viewer is essential for tasks such as comparing different manuscripts or examining artworks before and after restoration. This article introduces Mirador, a IIIF-compatible image viewer jointly developed by Stanford University and Harvard University. What is Mirador? Mirador is a web-based image viewer compatible with IIIF (International Image Interoperability Framework). Its most distinctive feature is its multi-window interface, which allows users to open multiple windows simultaneously to compare images. ...

March 15, 2026 · 3 min · Nakamura
Observable: Data Visualization Notebooks by the Creator of D3.js

Observable: Data Visualization Notebooks by the Creator of D3.js

Introduction Observable is a JavaScript-based data analysis and visualization notebook platform developed by Mike Bostock, the creator of D3.js. It provides an environment where you can write reactive code in the browser and instantly create interactive data visualizations. In the field of Digital Humanities (DH), Observable has gained attention as a powerful tool for exploratory data analysis and creating interactive visualizations of research data. Key Features of Observable Reactive Notebooks Observable notebooks share concepts with Jupyter Notebooks but adopt a JavaScript-based reactive execution model. ...

March 15, 2026 · 3 min · Nakamura
Omeka: A Platform for Digital Collections and Online Exhibitions

Omeka: A Platform for Digital Collections and Online Exhibitions

TL;DR Omeka is an open-source web platform designed for cultural heritage institutions such as libraries, museums, and universities. It specializes in managing digital collections and building online exhibitions, with two versions available: Omeka S (the latest version with Linked Data support) and Omeka Classic (the simpler legacy version). It is released under the GPL license. What is Omeka? Omeka is a web publishing platform developed by the Roy Rosenzweig Center for History and New Media (RRCHNM) at George Mason University. Its name derives from a Swahili word meaning “to display” — fitting for a platform optimized for publishing and exhibiting digital materials. ...

March 15, 2026 · 3 min · Nakamura
Palladio: A Guide to Humanities Data Visualization

Palladio: A Guide to Humanities Data Visualization

Introduction In historical and humanities research, visualizing data such as travel routes, correspondence networks, and chronological events is an important means of gaining new insights. However, GIS software and programmatic data visualization have traditionally been high barriers for many humanities researchers. Palladio is a web-based data visualization platform developed by the Humanities+Design Lab at Stanford University. Simply upload a CSV file, and you can explore your data through multiple views: maps, graphs, tables, and timelines. ...

March 15, 2026 · 3 min · Nakamura
RAWGraphs: A No-Code Data Visualization Tool for Digital Humanities

RAWGraphs: A No-Code Data Visualization Tool for Digital Humanities

TL;DR RAWGraphs is an open-source, browser-based data visualization tool. Simply drag and drop a CSV/TSV file to create over 30 types of charts, then export them as SVG or PNG. No programming required — making it an ideal entry point for data analysis in Digital Humanities (DH) research. What is RAWGraphs? RAWGraphs is an open-source project developed by the DensityDesign Lab at Politecnico di Milano, Italy. It is released under the Apache 2.0 license and is free for anyone to use. ...

March 15, 2026 · 3 min · Nakamura
ReplayWeb.page: A Browser-Based Web Archive Replay Tool

ReplayWeb.page: A Browser-Based Web Archive Replay Tool

Introduction In Digital Humanities, preserving and reproducing web content is a critical challenge. Websites are constantly updated and disappear, requiring mechanisms for long-term preservation of web pages as research subjects. ReplayWeb.page is a browser-based web archive replay tool developed by the Webrecorder project. It allows you to view archive files in WARC (Web ARChive) and WACZ (Web Archive Collection Zipped) formats directly in your browser. Key Features of ReplayWeb.page Client-Side Processing The most distinctive feature is its client-side processing using Service Workers. Traditional web archive replay tools (like the Wayback Machine) require server-side processing, but ReplayWeb.page completes all processing within the browser. This eliminates the need to build and maintain servers. ...

March 15, 2026 · 3 min · Nakamura
StoryMapJS: A Guide to Map-Based Storytelling

StoryMapJS: A Guide to Map-Based Storytelling

Introduction When telling stories tied to place — historical journeys, exploration records, cultural heritage distributions — map-based storytelling is remarkably effective. By sequentially tracing points on a map while displaying text and images at each location, readers can immerse themselves in the narrative while understanding its spatial context. StoryMapJS is a map-based storytelling tool developed by the Knight Lab at Northwestern University. Using a slide-based interface, you can create interactive narratives that journey through points on a map. It is licensed under MPL-2.0 and free to use. ...

March 15, 2026 · 4 min · Nakamura
Taguette: A Free Open-Source Qualitative Data Analysis Tool

Taguette: A Free Open-Source Qualitative Data Analysis Tool

Introduction Qualitative Data Analysis (QDA) is a research methodology that involves assigning tags or codes to text data — such as interview transcripts, field notes, and historical documents — to identify patterns and themes. Traditionally, commercial software like NVivo and ATLAS.ti has been widely used, but their expensive license fees can be a barrier for researchers and students. This article introduces Taguette, a free open-source qualitative data analysis tool that has gained attention as an alternative to NVivo and ATLAS.ti. ...

March 15, 2026 · 3 min · Nakamura