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 HL 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 information on a few custom image delivery settings: turning on image captions [pdf] and setting custom image size restrictions [pdf].

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:

More about PDS

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, GIF and TIFF 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.

IDS supports the delivery of the following MIME Types:
image/tiff (tiff images will not render directly in the browser unless the browser has a tiff reader plug-in)

Links to sample images delivered by IDS:

More about IDS

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:

More about SDS

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:

FDS URLs have the following syntax:[DRS ID]

Examples of FDS delivered files: -- plain text -- 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).