Editor’s Draft

Profile: Material artwork

The Material artwork profile supports digital reproductions of artworks that are moveable material objects, often, but not always, displayed in or maintained by museums. This includes photographic registration of 2D artworks, such as paintings or drawings, in high and very high (gigapixel) resolution and high-polygon scans of 3D artworks, such as statues or sculptures.

This content profile specifies how to package different media files (e.g., TIFF, JPEG, OBJ or MTL), their metadata and the relationships between them in a meemoo SIP package. It also allows extensions to the descriptive metadata using Schema.org.

Permalink: https://data.hetarchief.be/id/sip/2.1/material-artwork

Example Directory structure

2D photoregistration

root_directory
│── METS.xml
│── metadata
|   |── descriptive
|   |   └── dc+schema.xml
|   └── preservation
|       └── premis.xml
│
└── representations
   └──representation_1       # overview with frame
      │── METS.xml
      └──data
      │  └── PID_overzichtsopname_metlijst_tiff.tiff
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml
         └──preservation
            └── premis.xml
   └──representation_2       # overview without frame
      │── METS.xml
      └──data
      │  └── PID_overzichtsopname_zonderlijst_tiff.tif
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml    
         └──preservation
            └── premis.xml
   └──representation_3       # composed stitch 
      │── METS.xml
      └──data
      │  └── PID_stitch_tiff.tif
      │
      └──metadata
         |── descriptive     (optional)    
         |   └── dc+schema.xml    
         └──preservation
            └── premis.xml
   └──representation_4       # stitch 
      │── METS.xml
      └──data
      |  |── PID_deelopname1_tiff.tif
      |  |── PID_deelopname2_tiff.tif
      │  └── ...
      │
      └──metadata
         |── descriptive     (optional)  
         |   └── dc+schema.xml    
         └──preservation
            └── premis.xml

3D scan

root_directory
│── METS.xml
│── metadata
|   |── descriptive
|   |   └── dc+schema.xml
|   └── preservation
|       └── premis.xml
│
└── representations
   └──representation_1       # high-poly capture for print
      │── METS.xml
      └──data  
      │  └── PID_ARCH_STL.STL              
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml
         └──preservation
            └── premis.xml
   └──representation_2       # high-poly capture
      │── METS.xml
      └──data
      |  |── PID_ARCH_OBJ.OBJ       # polygon file    
      |  |── PID_ARCH_TIFF_COLOR.TIFF      # texture image       
      │  └── PID_ARCH_MTL.MTL              # texture mapping file
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml
         └──preservation
            └── premis.xml
   └──representation_3       # low-poly capture
      │── METS.xml
      └──data
      |  |── PID_VER_OBJ.OBJ       # polygon file    
      |  |── PID_VER_COLOR_BMP.BMP             # texture image       
      │  └── PID_VER_MTL.MTL                   # texture mapping file
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml   
         └──preservation
            └── premis.xml
   └──representation_4       # quality assessment reference
      │── METS.xml
      └──data
      |  |── PID_REF_OBJ.OBJ               # polygon file    
      |  |── PID_REF_BMP.BMP               # texture image      
      |  |── PID_REF_IJK_BMP.BMP           # reference texture image     
      │  └── PID_REF_MTL.MTL               # texture mapping file
      │
      └──metadata
         |── descriptive     (optional)
         |   └── dc+schema.xml    
         └──preservation
            └── premis.xml

Requirements

General

• There MUST be exactly one IE at the root. There MAY be other sub-IE’s that are part of the root IE or other sub-IE’s (e.g. to describe panels of a triptych individually).
• There MUST be at least one representation, but there MAY be multiple: either containing different captures or resolutions of the same IE or representing a different IE.
• Each representation MUST contain at least one file.
• Preservation metadata MUST be limited to the PREMIS metadata schema.
• There MUST be preservation metadata at the package level in the preservation/premis.xml file.
• There MUST be preservation metadata at the representation level in the preservation/premis.xml file.
• Only the MD5 hashing algorithm is allowed to compute the fixity, thus:
  • The value of element premis:premis/premis:object[@xsi:type="premis:file"]/premis:objectCharacteristics/premis:fixity/premis:messageDigestAlgorithm MUST be set to MD5.
  • The value of attribute premis:premis/premis:object[@xsi:type="premis:file"]/premis:objectCharacteristics/premis:fixity/premis:messageDigestAlgorithm/@valueURI MUST be set to "http://id.loc.gov/vocabulary/preservation/cryptographicHashFunctions/md5".

Package METS

• The csip:CONTENTINFORMATIONTYPE attribute MUST be set to OTHER and the csip:OTHERCONTENTINFORMATIONTYPE attribute MUST be set to https://data.hetarchief.be/id/sip/2.1/material-artwork.
• The TYPE attribute in the METS.xml file MUST be set to
  • Photographs - Digital (for 2D objects) or
  • Scanned 3D Objects (output from photogrammetry scanning) (for 3D objects).
• The mets/dmdSec/mdRef/@MDTYPE attribute MUST be set to OTHER and mets/dmdSec/mdRef/@OTHERMDTYPE attribute must be set to DC+SCHEMA.

Descriptive Metadata

• A descriptive metadata file descriptive/dc+schema.xml describing the IE MUST be present at the package level.
• A descriptive metadata file descriptive/dc+schema.xml describing the representation MAY be present at the representation level (e.g. to indicate diverting licenses).
• Descriptive metadata in dc+schema.xml MUST be limited to the DCTERMS and SCHEMA elements outlined in the basic profile.
• The DCTERMS and SCHEMA metadata MUST follow the basic profile requirements regarding the use of elements and attributes.
• Some descriptive metadata elements of datatype String MUST contain an attribute @xml:lang that indicates the language of the metadata element’s value (in order to, for example, specify a title or description in multiple languages); these are indicated with [@xml:lang=*] in the table below. Other elements MUST NOT contain this attribute.
• The value of the @xml:lang attribute MUST be a valid IETF BCP 47 language tag(see here for a list).

Validation

The XML files that are required by this profile can be validated using the following XML schema definitions:

Use Cases

Some use cases that implement this profile are:

• Two-dimensional artwork

• Scan of a three-dimensional artwork

• Gigapixel artwork