Staff Papers

The First Phase of the ImageSearch Project

An article by Debbie Campbell for LASIE, published in September 2000.



Abstract

The ImageSearch Project was an initiative of five of Australia's major cultural heritage institutions, to develop and test a single point of access to their digitised pictorial collections. The descriptions of the chosen images were provided in a single metadata schema, the Dublin Core, and gathered into a central repository at the National Library. The ImageSearch Project demonstrated benefits for both searchers and for the contributing institutions themselves, and has resulted in the decision to implement a new cultural heritage service for all Australians this year.

Author Information:
Debbie Campbell
Coordination Support Branch
National Library of Australia
Parkes Place
Canberra ACT 2600
Ph. +61 02 6262 1673
Fax. +61 02 6273 2545
Em. dcampbel@nla.gov.au


The First Phase of the ImageSearch Project

Introduction

The ImageSearch Project was conducted during 1998-99, to demonstrate the benefits of cross-searching the digitised pictorial collections of physically separated Australian cultural institutions from a single access point. The pictorial collections predominantly contain images of Australian cultural heritage.

The contributing institutions in the ImageSearch Project were the Australian War Memorial, the National Library of Australia, and the State Libraries of New South Wales, Tasmania and Victoria. Each of these institutions already provides access to a significant number of images via Web-based gateways. They are the Pictoria service of the State Library of Victoria, the photographic databases of the Australian War Memorial, the images from the heritage collections of Tasmania, the National Library's Images1 service, and the State Library of New South Wales' Index to Pictures and Manuscripts.

From these gateways, a total of 10,000 records describing a range of images held by the institutions were contributed to the ImageSearch demonstrator. Copyright of the images selected for the service resided with each contributing institution. In addition, links to copyright information have always been available through the Web gateways of the individual services for each institution's full pictorial collection.

There was no budget allocated to the ImageSearch Project. Each contributing institution provided copies of their metadata records, staff resources, and services-in-kind. For example, the State Library of New South Wales designed the home page and provided marketing opportunities, the State Library of Victoria provided an online feedback survey form, and the National Library of Australia coordinated the Project.


A vision for the ImageSearch Project

The Project arose out of a vision developed by the State Library of New South Wales and the National Library of Australia to explore the potential for a national image

searching service to go beyond the boundaries of individual library systems such as Online Public Access Catalogues, and beyond the constraints of proprietary image databases which restrict access on the basis of physical (human) presence.

The ability to digitise pictorial items for Web display has provided a successor to proprietary database formats. The application of a ubiquitous metadata schema (the Dublin Core) to distributed image collections has allowed images and their descriptions to be brought together for access via a single entry point.

Part of the vision for the entry point was to make it accessible to all Australians, free of charge.


Use of the prototype

The prototype, which remains available for use at www.nla.gov.au/imagesearch/, allows end users to key in one or more words across all of the metadata simultaneously, or by specifying individual metadata elements. The search then returns a list of brief descriptions from the metadata which include a link to the image (via a Universal Resource Locator or URL) at the contributing institution. A single click will provide access to the image, or to the full metadata record, which also gives access to the image. The searcher can then decide to click back to the ImageSearch prototype to link with other images, or search within the image service of the individual institution.


Aims of the ImageSearch Project

The aims of the ImageSearch Project were three-fold. Firstly, it provided a practical example of centralised metadata searching. A copy of the metadata describing a selected set of pictorial items from each contributing institution was gathered by harvesting software to be indexed in the central repository hosted at the National Library.

The original metadata schema used at each institution varied depending on resources available to create it, and re-use considerations. The State Library of Victoria implemented an early version of the Dublin Core metadata schema in 1996. The State Library of Tasmania uses a more recent version of the Dublin Core schema to describe its images. The other participants utilised conversion programs to create Dublin Core metadata. The National Library converted the MARC records created for the IMAGES1 service. The State Library of New South Wales converted its metadata from the internal Pictorial/Manuscripts (PICMAN) definition, and the Australian War Memorial also converted its internal military-related schema to the Dublin Core.

The generation of a common metadata set showed that while the institutions discriminate between individual items and aggregated collection description in different ways, these did not affect retrieval.

The second aim of the project was to provide a technical base for the participants to compare several operational features of their digitised image collections. There were differences in the quality of digitised images as well as different versions and uses of the HyperText Mark-up Language (HTML). Nevertheless, combining the images into a single point of access and delivery did provide some consistency of results to the searcher while still retaining contextual information which reflected the contributing institution. The discrepancies also provided a reference point to the contributing institutions for improvement of individual services.

The task of providing metadata to the ImageSearch prototype was considered to be unobtrusive, in the sense that it was already created for other purposes. The metadata gathering process can be activated at regular monthly intervals to ensure that new images are included in a timely fashion. Non-standard encodings were able to be ignored.

The third aim of the project was to ascertain the extent of benefits in collaborating to provide a national service to the Australian public. Each institution was able to make a diverse contribution based on the availability of skills. Benefits occurred in operational, content, and description aspects.


Benefits illustrated for searchers

While there might have been a commonality of operational approaches for online ordering services, the project actually highlighted significant discrepancies which may confuse searchers when submitting orders for reproductions of photographs or other images.

In a similar fashion, the application of thesauri was discussed at length. Each contributing institution had already made specific decisions about the thesaurus to be used in their own services. The State Library of Tasmania and the National Library of Australia use Library of Congress Subject Headings, the War Memorial uses a special theatre-of-war oriented thesaurus, and the State Library of New South Wales uses the PICMAN Topic Thesaurus. While there was insufficient metadata in the prototype to reach a definite conclusion, it was clear that through describing the images with one or two thesauri only, the consistency of search results improved.

However, a key discovery was the spread of images across the institutions representing the same themes. Many images are under-utilised because individual institutions' image collections are not considered to be the first, or an obvious, point of access. For example, the coverage of regional towns in the collections of the War Memorial and the National Library is very strong. Both the State Library of Tasmania and the State Library of New South Wales hold significant images of Antarctica.

There is a considerable benefit to the searcher in the ability to find images without initial knowledge of their location, or if known, without the restrictions sometimes imposed on physical access to the original. ImageSearch also demonstrated the value of being able to research distributed collections which may contain works by, or about, the same artist.


The future

The National Library is, as a result of this first phase of the project, cooperating with the first phase participants to develop and implement the ImageSearch Project as a new national cultural heritage service. The new service has its own cross-cultural identity, reinforced by a new logo and name - PictureAustralia. It is now available to all Australians for use, at www.pictureaustralia.org.


Biographical Note

Debbie Campbell was the Project Manager for the ImageSearch project. She has worked at the National Library since 1986. With an Information Technology background, Debbie has provided coordination services to the National Library's PANDORA project and the MetaWeb project. In 1998, she became the NLA's Metadata Coordinator with a particular responsibility for assisting national academic and government gateway projects to achieve the vision originally intended for the adoption of standard metadata schemas. This role expanded in late 1999 to encompass planning for national infrastructure projects including ImageSearch.

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