The Parker on the Web site brings together several commercial, open source, and locally built technologies to create an application for viewing and searching digital images, manuscript descriptions, and related bibliographic references. The two major components of the application are the search engine and image presentation application.
Search and Results Display
The Apache Group's open-source Lucene search engine powers the search and browse sections of the site. Lucene is used to create indexes of XML-encoded manuscript descriptions and a large database of related bibliographic references. The indexes are updated as new manuscripts are added to the site and as project bibliographers identify new citations to Parker manuscripts in related bibliography.
Brief results summary pages and all supporting pages in the site are rendered using the Struts framework (http://struts.apache.org/), JavaServer Pages, and Java tag libraries. The long manuscript descriptions, which contain transcriptions of full James catalogue entries, are derived from an XSLT transformation of the XML-encoded descriptions using the Saxon XSLT processor.
Image Display and Page Turning
Providing users with a fast and versatile means of smoothly viewing, zooming, and panning large, high-resolution images of manuscript pages was a critical challenge for the project. The image presentation component of the site takes advantage of JPEG2000 image file compression and an image server application that dynamically decodes JPEG2000 files for viewing and manipulation in the web browser without the need for plug-in or other third-party software. Scanned TIFF images of manuscript pages are encoded as lossy JPEG2000 files using the Aware SDK. Aware's JPEG2000 image server application decodes images and presents them as JPEG tiles to the web browser dynamically.
The Parker on the Web application is hosted on a dedicated Linux server environment and runs in a single Tomcat instance.