Metadata for images created by the National Library of Australia

The information below relates only to the metadata which applies to images. Metadata elements are not included for other formats, such as sound recordings and moving images, nor elements that are used to describe finding aids and descriptions of particular projects. The metadata is available for harvesting using the Open Archives Initiative (OAI) protocol for metadata harvesting – see National Library of Australia Digital Object Repository.

Division of the metadata

An item can have one or more images associated with it. For example, a picture may have just one image whereas a piece of sheet music will have 8 images for an 8-page work. As well, an item can consist of a number of parts. For example, an entry in a manuscript finding aid for diaries in 1870 may consist of three diaries each of which has 100 pages. The metadata has been divided into hierarchy in order to accommodate the structure of this range of material.

At the top of the hierarchy is the "work". A work may be a picture, a piece of sheet music or an entire manuscript collection. The work may have subunits, for example a piece of sheet music may have 8 pages, each of which is a subunit. Subunits may also have further subunits. For example, a manuscript collection may have a series called correspondence (first subunit level), the correspondence series may be divided into years (second subunit level), a number of pieces of correspondence may be in each year (third subunit level), and each piece of correspondence may have one or more pages (fourth subunit level). Some works, such as a single picture, do not have subunits.

An image is linked to the lowest level of the hierarchy. Potentially there can be a number of versions of this image. For example, there would be a master image, the thumbnail image and the larger image that users view online when they click on the thumbnail. There may also be a PDF version for printing on A4 paper. In addition, there may be previous versions of the master image, for example a master image before a map was cleaned versus an image after it has been cleaned (the Library does not intend to keep previous versions of images other than for the master image. All other images will be created from the latest master image).

There is metadata associated with each level of this hierarchy. The lower levels of the hierarchy inherit the rest of the metadata from its "parent". For example, the complete metadata for a particular image includes the image metadata as well as its subunit and work metadata.

Sources of metadata

There are six sources for the information:

1. TIFF header: the source of much of the technical information about the image.

2. Cataloguing record: source of the descriptive data for the image.

3. Image name: the file name the image is stored under, which is based on the image’s persistent identifier. See http://www.nla.gov.au/initiatives/nlapi.html for details about the persistent identifiers used by the National Library. It has between four and seven parts.

They are described briefly in the following table.

Prefix Identifies the collection type (and can be used for special display requirements). Examples: nla.mus for sheet music, nla.pic for pictorial works, and nla.ms for a manuscript collection.
Unique number Often the cataloguing record number on Kinetica (i.e. the amicus number). Examples: an464652549, ms51 for manuscript collection number 51.
First level of the hierarchy (used only when applicable). Example: the series within a manuscript collection
Second level of the hierarchy (again used only when applicable). Example: the folder within a series for a manuscript collection.
Part within an item Prefixed by "s" to denote that this is a sequence number which is used to ensure the parts of an item are displayed in the correct order. For example, the sixth page of a piece of sheet music would be s6.
Type of image Denotes the role of the image. Examples: m=master image, t=thumbnail.
File format tif or jpeg

Examples:

Pictorial item nla.pic-an464652549-m.tif
Sheet music nla.mus-an23221202-s1-m.tif
Manuscript nla.ms-ms51-2-950-s31-m.tif
Map nla.map-nk4185.tif

4. Constant: A digitiser can set up a constant in the object management software, developed by the Library, and have the constant apply to the next group of images created, for example: the machine and software used to create the images.

5. Generated: Some information is generated by the object management system. For example, the pixel width and length of the image and whether it is a portrait or landscape image.

6. Keyed: information keyed in by the digitiser. This is the source of only a limited number of metadata elements.

Some metadata elements are mandatory for all images, some are mandatory for particular types of images or depending on the source of the information used to create the metadata, and others are optional depending on whether the information is available.

Metadata used for images

The tables below list the metadata being created in the National Library of Australia for images. The source of each element is noted. The metadata elements have been grouped by functions.

A. Record status

This information applies to all levels.

Name Definition Obl1 Form Source Comments
dateTimeCreated Date and time the record was created M Date/Time Generated ISO standard
recordCreator Agent responsible for creating the record M Identifier Constant: ILMS metadata records are created initially from the cat record in the library’s management system
dateTimeUpdated Date and time the record was last updated M Date/Time Generated ISO standard
recordUpdater Agent responsible for last updating the record M Identifier Constant The Digitisation Team is classed as one agent

1 M=Mandatory, C=required if applicable, O=added when available

B. Work

DC Name Definition Obl1 Form Source Comments
identifier workPID The persistent identifier assigned to the work M Text Image name This can be used as the unique key for this work
immutable The unique identifier of the catalogue entry C Text Cat record Used for records sourced from the ILMS
workNo A unique number associated with a work for collection management purposes O Text Image name Taken from the "part within an item" in the image name
subunitNo Number for the subunit intrinsic to the arrangement of the parent work, eg page number. O Text Keyed I, ii, iii; 1, 2, 3, A, B, C, etc.
standardID A standard identifier such as ISSN, ISBN or ISMN assigned to the work. O Text Cat record  
type collection The collection to which the work belongs. M Code Image name Examples: nla.bk (book); nla.ms (manuscript); nla.map (map); nla.pic (picture)
form The form of the work if different from that implied by collection. O Code Keyed Same values as collection above
bibLevel The bibliographic level of the work M Code Cat record Values: set, item, part
digitalStatus Identifyies whether the work or any of its descendents has been digitized M Code Generated Digitised; Non-digitised; Partially digitised. Used, for example, when one part of a manuscript collection has been digitised
  subunit Type The subunit type, eg page number, cover, series, index M Text Keyed Used in conjunction with subunit number for display and searching, eg go to page 31
title title The name given to the work by the creator or publisher. O Text Cat record  
otherTitle Another name by which the work is known. O Text Cat record  
creator creator The entity primarily responsible for creating the work. O Text Cat record  
creatorStatement A statement of responsibility associated with the work. O Text Cat record  
background Biographical or administrative history note O Text Cat record  
subject subject A subject heading that describes the topic of the work O Text Cat record  
occupation A term that describes the occupation of the subject. O Text Cat record  
description notes A general note about the work. O Text Cat record  
summary A summary of the scope of the work O Text Cat record  
contents A note listing the contents of the work O Text Cat record  
publisher publisher The publisher of the work. O Text Cat record  
pubPlace Place of publication of the work. O Text Cat record  
contributor contributor Another entity who has made a significant contribution to the work. O Text Cat record  
date pubDate Any dates or date ranges associated with the creation or publication of the work. O Text Cat record  
startDate The first date associated with the work, expressed in date form for searching purposes. O Date Cat record layout: YYYY
endDate The last date associated with the work, expressed in date form for searching purposes. O Date Cat record layout: YYYY
format extent Physical description of the work O Text Cat record  
relation parentPID The persistent identifier assigned to the parent work C Text Image name Mandatory if work is a subunit
series A series of which this work is a part. O Text Cat record  
indexes Identifies indexes listing the contents of the work O Text Cat record  
coverage coverage The spatial coverage of the work. O Text Cat record  
rights access Restrictions on access note O Text Cat record  
rights Terms governing use and reproduction of the work O Text Keyed  

1 M=Mandatory, C=required if applicable, O=added when available

C. Copy: descriptive data

DC Name Definition Obl1 Form Source Comments
identifier copyPID A persistent identifier (PID) assigned to the copy M Text Image name  
currentVersion A code indicating whether this is the current version M Boolean Generated Values: Y,N
version The version number of the copy O Pos. integer Generated Values: 1,2,3…
accessionNo A unique number assigned by the Library to a copy when it was accessioned. O Text Cat record  
callNo A number uniquely identifying the physical location of a copy O Text Cat record Digital copies may have a physical location if stored offline.
otherNo Other numbers associated with the copy O Text Cat record  
type copyType A code distinguishing physical from digital copies M Code Generated Values: p(physical), d (digital)
copyRole A code distinguishing the role played by a copy in use of the work M Code Image name Examples: o (original); t (thumbnail); v (view); m (master); c
(co- master)
date dateCreated For replicas, the date the copy was created C Date Generated Process:dateStarted
source sourceCopy For replicas, the copyPID of the source copy C Text Generated Process:inputCopy
description notes A general note about the copy O Text Keyed  
condition A description of the condition of the copy O Text Keyed  
relation exhibition Information about exhibitions in which the copy has appeared O Text Keyed  
rights access A code indicating any access conditions O Code Keyed Unrestricted; Copyright; Indigenous; Adult content
expiry date The year in which an access condition expires C Date Keyed ISO (YYYY)

1 M=Mandatory, C=required if applicable, O=added when available

D. Copy: technical data

DC Name Definition Obl1 Form Source Comments
format resolution The spatial resolution of the image, eg 300dpi M Positive integer TIFF header, tag 258  
bitDepth The pixel depth or tonal resolution of the image M Positive integer TIFF header, from tags 282 and 283  
colourSpace The colour space of the decompressed image M Text TIFF header, tag 262 where
0=bitmap
1=greyscale
2=RGB
Photometric Interpretation in the NISO draft
orientation A code designating the orientation of the image M Code Generated portrait; landscape
imageWidth The width of the image in pixels M Positive integer TIFF header, tag 256 horizontal or x dimension
imageLength The length of the image in pixels M Positive integer TIFF header, tag 257 vertical or y dimension
colourProfile A code indicating whether the Colour Profile resides within the image or at an external location O Code Constant or keyed within image; external
CPLocation The URL of the Colour Profile if stored externally C URI Constant or keyed Mandatory if ColourProfile="external"

1 M=Mandatory, C=required if applicable, O=added when available

E. Copy: tools used to create the image

Name Definition Obl1 Form Source Comments
toolCategory A code designating whether the tool is a device or software M Code Constant d (device); s (software)
toolType A code designating the type of tool. M Code Constant Values: transmission scanner; reflection print scanner; digital still camera; still from video; image capture software; OCR software; other
toolName The manufacturer, name or number and version. M Text Constant  
toolResolution Maximum tool optical capture resolution. O Text Constant Eg 800x1600 ppi.
notes Notes. O Text Keyed  

1 M=Mandatory, C=required if applicable, O=added when available

1 NISO Draft Standard. Data Dictionary. Technical Metadata for Digital Still Images. Working Draft, 1.0. July 5, 2000.