Recommended Media Object Creation Standards
Appendix to the "Positioning
for Our Future" LofT Report
April 10, 2001
Audio
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Purpose/Goal |
Recommended Attributes/ Formats |
Comments |
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Archival quality |
Attributes: Color - 24 bits per pixel, Grayscale - 8 bits per pixel, 400-600 dpi or 3000 pixels on longest side (whichever produces more data), embedded color profile File format(s): TIFF with lossless, (LZW), file compression |
Color reference should be provided, particularly for surrogates of artworks or rare materials, e.g. paintings, books, manuscripts. |
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Service quality |
Attributes: Reduced bit-depth and/or spatial resolution from archival quality File format(s): JPEG, GIF, PNG, TIFF, PICT |
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Deliverable quality |
Attributes: Reduced bit-depth and/or spatial resolution from service quality File format(s): JPEG, GIF, PDF, PNG, TIFF, PICT |
Images, esp. those of text, may be reduced to 1 bit per pixel, e.g. B/W, when primary output will be to a printer. PDF files may be particularly useful since multiple images may be collected into a single file. |
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Preview/Thumbnail quality |
Attributes: 8 or 16 bits per pixel as appropriate for file format, 72-200 dpi or approx. 1.5" x 1.5" File format(s): GIF, JPEG, PNG |
Images, Vector
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Purpose/Goal |
Recommended Attributes/ Formats |
Comments |
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Archival quality |
Attributes: File format(s): EPS, SVG, proprietary formats, e.g. Adobe Illustrator |
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Service quality |
Attributes: File format(s): EPS, SVG, SWF |
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Deliverable quality |
Attributes: File format(s): |
Vector images may be converted to raster formats for delivery. |
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Preview/Thumbnail quality |
Attributes: 8 or 16 bits per pixel as appropriate for file format, 72-200 dpi or approx. 1.5" x 1.5" File format(s): GIF, JPEG, PNG |
Text
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Purpose/Goal |
Recommended Attributes/ Formats |
Comments |
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Archival quality |
Attributes: SGML/XML encoded text with accompanying DTD and other dependent files File format(s): plain text |
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Service quality |
Attributes: maintains most, if not all, structural and formatting characteristics as well as "searchability" of the archival file File format(s): XML, RTF, PDF, proprietary word processor formats |
Open standards are preferred. PDF files in this context must have embedded, searchable text. |
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Deliverable quality |
Attributes: maintains few, if any, structural and/or formatting characteristics. Maintains "searchability" of text, but not in conjunction with structure. File format(s): HTML, PDF, unstructured ASCII, e.g. OCR output |
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Preview/Thumbnail quality |
None possible? Search interface? |
Video
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Purpose/Goal |
Recommended Attributes/ Formats |
Comments |
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Archival quality |
Attributes: Storage media: user-created video - NTSC DV or DVCAM tape, purchased materials - DVD |
Tapes should be stored in environmentally stable location, e.g. vault. |
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Service quality |
Attributes, Storage media, and File format(s): Select as appropriate for the task. |
Service, e.g. editable, versions produced as required by "dubbing", e.g. changing storage medium or format. Digital versions not appropriate for long-term storage due to very large file sizes; therefore, not easily distributed via electronic means. |
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Deliverable quality |
Attributes: video compression applied File format(s): MPEG, RealMedia, QuickTime |
Only highly compressed output forms are appropriate for storage on hard disks. |
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Preview/Thumbnail quality |
Attributes: A representative frame with dimensions equal to or less than the video frame size formatted as a GIF, JPEG, or PNG may serve as a preview of the video's content File format(s): frame - GIF, JPEG, PNG; clip - same as deliverable |
Possible detail: single representative frame - 8 or 16 bits per pixel as appropriate for file format, 72-200 dpi or approx. 1.5" x 1.5", clip - same as deliverable but reduced duration |
Definitions
Archival quality: maintains highest quality representation, output, and editing capabilities.
Service quality: representative and output qualities are reduced, but file remains editable. Multiple files may be created at this level for multiple purposes or user communities.
Deliverable quality: representative and output qualities may be reduced; end user, however, is not expected to edit the delivered file. Multiple files may be created at this level for multiple purposes or user communities.
Preview/Thumbnail quality: highly reduced in quality and size or duration, functions as an identifier; has little or no output or editing value.
