supporting significant properties in a working archive (sps part 5), by stephen grace and gareth...
DESCRIPTION
This presentation, the fifth of six parts on the practical analysis of significant properties of digital objects, seeks out tools capable of extracting and maintaining properties for an archival-scale number of objects. The presentation was given as part of module 3 of a 5-module course on digital preservation tools for repository managers, presented by the JISC KeepIt project. For more on this and other presentations in this course look for the tag 'KeepIt course' in the project blog http://blogs.ecs.soton.ac.uk/keepit/TRANSCRIPT
Supporting SPs in a working
archive: Software Tools
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Challenge
Reality: Infeasible to perform manual maintenance of large number of objects. Require software capable of extracting & maintaining SPs for large of objects
Requirements:1. Object analysis tools
• Support requisite formats• Identify all/some SPs• Support batch analysis• Ideally well supported and documented
2. Description schemas to record SPs• Flexible• Machine and format idependent
3. Conversion/emulation tools capable of maintaining SPs
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Format identification
•File identification through Magic Number and ‘light touch’ scan of encoding structure.•Recognise 100s (potentially 1000s) of formats•Provide basic encoding info, but not detailed structure•Examples:• File (1): Free version created in 1986 & available for all
operating systems.http://gnuwin32.sourceforge.net/packages/file.htm (Windows)• DROID: Java app developed by TNA. Integration with
PRONOM. Format ID & assignment of PUID, which can be linked to preservation planning. http://droid.sourceforge.net/. • FFIdent: Java library to ID and extract basic information.
Recognizes 27 encoding formats using header information (magic number & common structural information)
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Detailed Analysis
•Email:• Aperture - Java framework able to decode structured text
and convert to other format• ReadPST: Open source tool for processing Outlook PSTs• XENA - Java tool developed by NAA
•Audio:• MP3Info - technical info viewer and ID3 1.x tag editor that
supports the MP3 file format. • SoX/SOXI (Sound eXchange): extracts descriptive MD and
technical info• MetaFlac: Extractor tool for FLAC audio.
•Images:• TiffInfo• ImageMagick• JHOVE
Perform detailed analysis of internal structure of one or more files.
See InSPECT Testing Reports available at http://www.significantproperties.org.uk/
for further info on these tools
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JHOVE 1/2JHOVE (http://hul.harvard.edu/jhove/)•Format-specific digital object validation API written in Java•Functionality: Format identification, Format validation, Format Characterisation•Supports: AIFF, ASCII, Bytestream, GIF, HTML, JPEG, JPEG 2000, PDF, TIFF, UTF-8, WAV, and XML.
JHOVE2 (https://confluence.ucop.edu/display/JHOVE2Info/Home)•Supports: JPEG 2000, PDF, SGML, Shapefile, TIFF, ASCII & UTF-8 encoded text, WAVE, XML, ICC color profile•Functionality: Format identification, validation, feature extraction & policy-based assessment
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JHOVE Demo
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XCL (eXtensible Characterization Language)•Content extraction• Extracts content & tech properties through use of XCEL and saved as XCDL.
•Format support:• PNG, TIFF, GIF, BMP, JPEG, JP2, PBM, PCD, PCX, PICT, PPM, PSD, SVG, TGA, XBM and XPM, MS DOC, DocX, PDF
•Content comparison• Compare 2 objects e.g. TIFF & PNG, PDF & Doc
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XCL Extract & compare
Object A
Object B
Format A XCEL
Format B XCEL
Conversion Extractor Comparator
Object A XCDL
Object B XCDL
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XCL Demo
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Final thoughts
•Analysis tools useful, but have problems:• Limited format support•Variable access methods (GUI, CLI, APIs)• Inconsistent reporting process•Different metrics (e.g. text vs. no.)•Metric variations (e.g. milliseconds)
•Partial solution: Wrap tools into services• PLANETS Interoperability Framework