TIB understands significant properties to be properties of a homogenous group of objects that have to be preserved, taking into account the resources available, in order to preserve the object in the most authentic state possible, irrespective of format. This reflects the objective of the digital archive of securing the long-term accessibility of objects.
The Digital Preservation team derives the designated communities’ requirements concerning digital preservation and the significant properties from the main use scenario and the designated community requirements for three exemplarily object groups.
A differentiation is made between technical significant properties and organisational significant properties.
At present, TIB writes all extractable technical metadata as significant properties. All significant properties are indexed, and can be used as search parameters in the event of queries. It is assumed that access requirements will change over time, and significant properties may not be defined in advance with regard to a particular target format or a particular preservation strategy.
Designated community requirement | Conversion based on significant property / requirement governing preservation | Organisational | Technical |
---|---|---|---|
Availability and simple access | Standardised, open format | x | |
| Common format within the community | x | |
Citability | Is covered by means of access platforms | x | |
| Accompanying metadata | x | |
Trustworthiness of objects as a scientific source | Logging of all modifications in the accompanying metadata | x | |
Preservation of representation | Preservation of representation | x | |
Content elements (text) | Embedded fonts | x | |
| Text stream length (number of characters) | x | |
Content elements (tables, images) | Number and position of content elements (text, tables, images, …) | x | |
Colour | Colour space | x | |
Number of pages and page layout | Number of pages, page size and orientation | x | |
No loss of quality | No lossy compression | x | |
| Choice of an appropriate target format / emulation environment | x | |
Portability and platform-independent representation | Choice of an appropriate presentation format in consultation with the access platform | x |
Designated community requirement | Conversion based on significant property / requirement governing preservation | Organisational | Technical |
---|---|---|---|
Availability and simple access | Standardised, open format | x | |
| Common format within the community | x | |
Citability | Is covered by means of access platforms | x | |
| Accompanying metadata | x | |
Trustworthiness of objects as a scientific source | Logging of all modifications in the accompanying metadata | x | |
Preservation of the representation | x | ||
Length and width | Length x, width y | x | |
Quality | Resolution | x | |
| Bit depth | x | |
Colour | Colour space | x | |
No loss of quality | No lossy compression | x | |
| Choice of an appropriate target format / emulation environment | x | |
Portability and platform-independent representation | Choice of an appropriate presentation format | x |
Designated community requirement | Conversion based on significant property / requirement governing preservation | Organisational | Technical |
---|---|---|---|
Availability and simple access | Standardised, open format | x | |
| Common format within the community | x | |
Citability | Is covered by means of access platforms | x | |
| Accompanying metadata | x | |
Trustworthiness of objects as a scientific source | Logging of all modifications in the accompanying metadata | x | |
Preservation of acoustic representation | x | ||
Duration | Length in HH:MM:SS | x | |
Quality | Bit depth | x | |
| Bit rate | x | |
Bitrate – Mode (constant / variable) | x | ||
Mono/stereo/surround | Number of channels | x | |
No loss of quality | No lossy compression | x | |
| Choice of an appropriate target format / emulation environment | x | |
Portability and platform-independent representation | Choice of an appropriate presentation format | x |
Designated community requirement | Conversion based on significant property / requirement governing preservation | Organisational | Technical |
---|---|---|---|
Availability and simple access | Standardised, open format | x | |
| Common format within the community | x | |
Citability | Is covered by means of access platforms | x | |
| Accompanying metadata | x | |
Trustworthiness of objects as a scientific source | Logging of all modifications in the accompanying metadata | x | |
Preservation of all separate streams | Number and order of videostreams, audiostreams, datastreams | x | |
| Descriptive metadata like language version, title | x | |
Preservation of the visual appearance | x | ||
duration | duration in HH:MM:SS.fff | x | |
Heigth and width | heights x, width y | x | |
| Display Aspect Ratio | x | |
| Pixel Aspect Ratio | x | |
quality | Bitdepth | x | |
| framerate | x | |
Rendering | Standard (NTSC/PAL) | x | |
| ScanType (progressive, interlaced) | x | |
| ScanOrder (Top Field First, Bottom Field First) | x | |
Colour | Colour Space | x | |
| ChromaSubsampling | x | |
| Colour Range | x | |
| Colour Transfer | x | |
| Colour Primaries | x | |
| Chroma Location | x | |
Preservation of the audible appearance | See: Significant Properties of Audio Files | x | |
Preservation of all data streams | x | ||
Subtitles | Subtitles | x | |
| Closed Captions | x | |
TimeCode | TimeCode | x | |
| Other data streams (e.g. menus, text,…) | x | |
No loss of quality | No lossy compression | x | |
| Choice of an appropriate target format / emulation environment | x | |
Portability and platform-independent representation | Choice of an appropriate presentation format | x |