Digital Collections
 
DIGITAL COLLECTIONS INFRASTRUCTURE

The infrastructure to support the Library's digital collections continues to be developed through the Digital Services Project. This includes support for the capture, storage, management, identification, access, delivery and long-term preservation of digital collections. This paper provides more information about the infrastructure.

Storage

The Library uses a Digital Object Storage System to store its digital collections. A structured file system has been developed to store images and sound files, digital master files are stored on tape and derivatives for viewing on the web are stored on disk. This system has been recently upgraded to 18TB capacity of online disk and 60 TB of nearline tape.

Capture and Management

The Library has developed a database application called Digital Collections Manager (DCM) to assist with the management of its digital collections. DCM supports workflow processes such as digitisation and upload and download of files to and from the Library's storage system. Currently DCM supports the digitisation of pictures, maps, manuscripts, printed music, books and serials, and audio, as well as preservation processes. Future enhancements to DCM will include additional support for sound files, and rights management information. Information stored in DCM includes: bibliographic metadata sourced from the Library's catalogue; technical metadata, which is usually extracted from the digital objects such as image format, resolution, dimensions, or audio bit and sample rates; and structural metadata describing the digital files that make up an object, and their relationships. The data stored in DCM is also used as the foundation for web delivery of the Library's digital collections.

Identification

The Library has adopted a naming scheme for persistent identification of its digital collections and developed a resolver to ensure that digital collections can be cited and referenced online with confidence.

Access and Delivery

A delivery system that provides web access to digital collections, in context with their bibliographic descriptions and facilities for page turning, zoom-in, zoom-out and other navigation aids, was developed based on the DCM data store. Features of the delivery system vary based on the form of the material being delivered. For example, for maps, the ability to quickly zoom-in to any selected area of an image is provided using image compression technology. Material being delivered at present is in the public domain. In future, access control will be possible based on restrictions that apply to the digital collections and the location or registration of users. A new generic delivery system is under development, with the intention of providing a more unified approach across the different forms of material being delivered.

The delivery system is the back-end to metadata-based resource discovery systems, such as the Library's catalogue and federated services including Libraries Australia, Picture Australia and Music Australia.

The Library's digital collections are also available for indexing by Internet search engines. This is made possible via a service that exposes persistent identifiers for the Library's digitised books (both Australian and other), manuscripts, maps, pictures and sheet music. In addition, an OAI interface to DCM has been created to provide access to descriptive metadata for pictures, sheet music, maps, manuscripts and books & serials from the Library's digital collections. Federated services such as PictureAustralia are also available for indexing. Please contact us for information about indexing our digital collections.

Preservation

Preservation is one of the great challenges of the digital age, and many of the emerging issues in digital preservation are accessible through the Library's PADI gateway to digital preservation resources. Strategies being adopted by the Library to meet this challenge include using the Digital Collections Manager to store a history of information about digital preservation processes. These processes will involve format migration pathways identified for each type of digital object.

Systems Framework

A systems framework is being developed that supports a broad range of functions including the capture, storage, management, identification, access, delivery and long-term preservation of digital collections. The Library is committed to the ongoing development of its catalogue as the primary access point for its physical and digital collections, along with federated, metadata-based resource discovery services such as Libraries Australia , Picture Australia and Music Australia that cross organisational and domain boundaries.

A simplified architecture for access to digital collections is shown below.

Digital collections architecture