National Library of Australia - Gateways

ISSN 1039-3498 | no. 62 | April 2003


Managing our Digital Collections

In 2001 the Library embarked on a major digitisation programfor pictures, maps, sheet music and manuscripts from the Collection. The material digitised is a unique part of Australia’s cultural heritage. It includes photos by photographers such as Harold Cazneaux, Max Dupain and Frank Hurley; maps of the world, the Pacific and Australia issued before 1900 (including 16th–17th century Dutch and French items tracing the development of exploration as well as maps of early land settlement in Australia); pre-1930s Australian sheet music; and manuscript material such as letters, diaries, speeches and objects from Australian Prime Ministers such as Sir Edmund Barton and Alfred Deakin.

Once this material has been digitised, either by use of a flatbed scanner or digital camera, the resulting digital files need to be effectively managed for long-term storage, preservation and access. The Library has developed a database called Digital Collections Manager (DCM), to manage this digital material. The Library made a strong effort to base this on a digital asset management system available in the marketplace, but it was not able to identify a system which was both affordable and closely matched to the Library’s needs, so chose to develop the database in-house.

The Digital Collections Manager is used by Library staff and supports the digitisation process, the creation of derivative objects for web delivery (for example low resolution thumbnail and view copy JPEG images), and the storage of technical metadata and digital files. DCM currently supports management of images (including pictures, maps, sheet music and manuscript materials) and is being enhanced to support management of audio recordings from the Oral History Collection. Later in 2003 it will be further enhanced to support recording of rights management information and information used for preservation management.

The metadata supported by the DCM data model includes:

  • descriptive metadata sourced from the Library’s catalogue;
  • administrative metadata, including technical metadata, for example image format, resolution, dimensions, audio bit and sample rates, rights management and preservation metadata; and
  • structural metadata describing the files that make up a digital object and their relationships.

The functional specifications for DCM have been published on the Library’s web site <www.nla.gov.au/dsp/doms/dcm.html>. DCM provides an easy to use web interface to the Library’s digital collections. It also enables digitisation staff to upload new TIFF master files to the Library’s mass storage system and the system automatically creates JPEG derivatives for viewing on the Web. Staff can search for a work item, file, job or project using title, creator and other metadata fields held in the database. Once they have found a work that has been digitised, they can view and download digital copies of the work including digital master files and web derivatives.

For example, you can use DCM to find all images in the Pictures Collection that were created by Frank Hurley where the title includes the words penguin(s) or seal(s). There are five records in DCM that meet these criteria:

Screen displaying works 1 - 5 retrieved by your search for Creator 'hurley frank' and Title 'penguin' and Title 'seal'  limited to collection, 'Picture'

The details for the second work in the results list, a photograph of penguins on Macquarie Island created by Frank Hurley during the Australian Antarctic Expedition in 1911, includes more information on the wreck of the sealing ketch Gratitude and other details including call numbers for the negative within the Hurley collection:

Screen displaying work details for nla.pic-an23478505

Using DCM, Library staff can view the process history of a digital object including information on when the item was digitised to create a high resolution digital master and ‘ingested’ into the Library’s mass storage system; and what co-masters (masters created as the source for derivative copies) and web derivatives were created. Over time, this feature will be used to record changes to storage formats and other preservation processes that may be undertaken on a digital object:

Screen displaying all current copies of nla.pic-an23478505

For every digital file, technical metadata is extracted and stored in DCM including a checksum that can be used to validate the integrity of the digital file:

Screen displaying Master copy details for nla.pic-an23478505

Every digital object managed by DCM is assigned a persistent identifier, which allows Library users to access the material on the Web via a simple resource locator. A publicly accessible digital copy of this collection item is available at: <http://nla.gov.au/nla.pic-an23478505>.

In tandem with the development of DCM, the Library is creating tailored delivery systems for digital objects so that Library users can get online access to our digital collections. To date web delivery systems for sheet music and maps have been released, as reported in Gateways numbers 58 and 60.

The web delivery systems use information stored in DCM to provide access to collection items along with descriptive and contextual metadata. The user interface allows the user to navigate the multiple parts of the object, and to zoom in to view details of each part. The delivery system is accessed using the Library’s resolver service allowing objects to be permanently cited using a persistent identifier.

In the case of manuscripts, the delivery system needs to be closely tied to the finding aid which describes the collection and which lists the series and individual items within that collection. Manuscripts and other multi-page items (such as music scores and rare books) also require a flexible page turning capability.

In the case of maps, users need a powerful zoom capability, and a means of identifying their current zoom location on the whole map. The MrSID technology <www.lizardtech.com/solutions/geospatial/technologyoverview/> provides these features, and is an integral part of the Library’s maps delivery system.

The Digital Collections Manager database is a key component in the Library’s digital services technical architecture that is enabling better management of our digital collections.
—Tony Boston, Director, Digital Services

| Contents list for this issue of Gateways |


Please address any comments and enquiries to The Editor, Gateways: gateways@nla.gov.au