Delivery systems
The Library Digital Initiative has developed a suite of services for delivering to web browsers common types of digital objects stored in the HUL Digital Repository (DRS). Each service provides secured access that allows material to be limited to the Harvard academic community (i.e., those with a Harvard ID number and PIN) or made available to the public.
Page Delivery Service (PDS)
Image Delivery Service (IDS)
Streaming Delivery Service (SDS)
File Delivery Service (FDS)
Full-text Search Serivce (FTS)
Asynchronous Delivery Service (ADS)
See also the document Image Captions [pdf] if you are interested in applying captions to deliverable images.
Page Delivery Service (PDS)
Page Delivery Service (PDS) delivers to a web browser scanned page images of books, diaries, reports, journals and other multi-page documents from the collections of the Harvard libraries. PDS provides tools for page-turning navigation that permit viewers to browse tables of contents, view "next" and "previous" page images and move between sections.
Multi-page digital objects such as books, reports, articles, pamphlets, scrapbooks or photo albums make good candidates for inclusion in PDS. PDS may also be used for multiple views of a single object.
Links to sample documents delivered by PDS:
- A book from Schlesinger Library
- Historic legislation concerning Harvard from the Harvard University Archives
- A photograph album from Harvard-Yenching Library
- A musical score from the Loeb Music Library
- A manuscript from the Arnold Arboretum
Image Delivery Service (IDS)
IDS delivers to a web browser digital still images. In general, images available through this service have been converted from photographs, slides, prints, and other two-dimensional media held in special collections throughout the University. IDS is the service that delivers many of the digital images described in the VIA catalog, but it can also serve images cataloged in HOLLIS, OASIS, or any other catalog or web site that supports URL linking. IDS can secure images to the Harvard community (i.e., those with a Harvard ID number and PIN) when appropriate. Besides providing static delivery for JPEG images, IDS also provides dynamic delivery as well as static delivery for JPEG2000 files. Dynamic delivery includes navigation, zooming and delivery of multiple sizes and resolutions of a single digital image.
Links to sample images delivered by IDS:
- Static delivery of a JPEG image from Harvard-Yenching Library
- Static delivery of a JPEG2000 image from Baker Library, Harvard Business School
- Dynamic delivery of a JPEG2000 image from the Harvard Map Collection of the Harvard College Library
- Dynamic delivery of a JPEG2000 image from the Ernst Mayr Library at the Museum of Comparative Zoology
Streaming Delivery Service (SDS)
SDS delivers digital audio that is stored in the Digital Repository Service (DRS) to web browsers.
Link to a sample of audio delivered by SDS:
- World music from the Loeb Music Library
File Delivery Service (FDS)
The File Delivery Service (FDS) delivers to a web browser PDF files, ZIP Containers, Text Files, XML files, SGML files and ICC color profiles (used in digital imaging) deposited into the DRS and enabled for public delivery. For file formats not natively supported by web browsers, the user will be prompted to save the file to the local computer where it can be opened and viewed using local rendering applications.
FDS supports the delivery of the following MIME Types:
application/pdf
application/x-icc
application/zip
text/plain
text/sgml
text/xml
FDS URLs have the following syntax: http://fds.lib.harvard.edu/fds/deliver/[DRS ID]
Examples of FDS delivered files:
http://fds.lib.harvard.edu/fds/deliver/123530 -- plain text
http://fds.lib.harvard.edu/fds/deliver/13768034 -- PDF
To be delivered by FDS, a file must be enabled for public delivery (that is, its DRS access flag must be set appropriately). Files that are not enabled for public delivery can be downloaded using DRS Web Admin.
Full-text Search Service (FTS)
FTS provides a mechanism for efficient indexing and retrieval of electronic full text stored in DRS. Search options include Boolean operators (AND, OR, NOT), quoted phrases, and proximity. For indexed text items that have dates associated with them, searches can be qualified by a date or date range. The FTS server is accessed as an option of PDS for searching the full text (such as OCR) of page-turned objects. The FTS server can also be accessed directly, as in the case of the Harvard-Radcliffe Online Historical Reference Shelf. See Creating an FTS Search Form for more about offering FTS search from an external web site.
Links to examples of FTS search forms providing full text searching capability to images in PDS with associated full text in DRS:
- Search form for the Arnold Arboretum Papers of Joseph F. C. Rock, 1922-1962
- Search form for the Harvard/ Radcliffe Online Historical reference Shelf
Asynchronous Delivery Service (ADS)
ADS allows DRS Depositors and Owners to request large sets of DRS objects for downloading upon e-mail notification. This service is used in conjunction with DRS Web Administrative Interface (DRS Web Admin).