17. An image <basic information> <rendering information> <storage information>
18. An image <basic information> (implicit / explicit) <rendering information> (implicit / explicit) <storage information> (implicit / explicit) … and the data?
19. An image <basic information> (implicit / explicit) <rendering information> (implicit / explicit) <storage information> (implicit / explicit) … and the data?
20. An image Data either as data stream 1,1,1,1,1,1, 0,0,0,1,1,1, 0,1,1,1,1,0, 1,1,1,1,0,1, 1,1,1,1,1,1 1 1 1 1 1 1 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 1 0 1 1 1 1 1 1 1
21. An image Data either as data stream or as processing instructions SetSize: 5 by 6 SetBackgroundColor: Yellow SetForegroundColor: Red SetLetterHeight: 4 MoveTo: 3,5 DrawLetter: T 1 1 1 1 1 1 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 1 0 1 1 1 1 1 1 1
22. File format <basic information> <rendering information> <storage information> <data>
23. File format <basic information> What to do? <rendering information> <storage information> <data>
24. File format <basic information> What to do? <rendering information> How to do it? <storage information> <data>
25. File format <basic information> What to do? <rendering information> How to do it? <storage information> How to move it from persistent to deployed form? <data>
26. File format <basic information> What to do? <rendering information> How to do it? <storage information> How to move it from persistent to deployed form? <data> What to deploy?
27. File format <basic information> What to do? <rendering information> How to do it? <storage information> How to move it from persistent to deployed form? <data> What to deploy?
42. Bit rot One byte is damaged, one byte cannot be displayed correctly. 002 004 234 123 234 156 127 xxx 221 221
43. Bit rot One byte is damaged, ten bytes cannot be displayed correctly. 002 xxx 234 123 234 156 127 178 221 221
44. Result: http://www.cflr.beniculturali.it/Progetti/Fixit.php www.cflr.beniculturali.it Franco Liberati [email_address] Università di Roma “La Sapienza” Dipartimento Informatica Centro Fotoriproduzione Legatoria e Restauro Paolo Buonora [email_address]
45. Paolo on JPEG JPEG2000 more robust against bit rot than TIFF.
46. Paolo on JPEG JPEG2000 more robust against bit rot than TIFF. So, to stinulate more empiricism …
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57. What kind of file is this? Two ways to identify a file: (b) By internal characteristics („magic number“, „signature“). A TIFF file begins with … Bytes 0-1: The byte order used within the file. Legal values are: “ II” (4949.H) / “MM” (4D4D.H) Bytes 2-3 An arbitrary but carefully chosen number (42) that further identifies the file as a TIFF file.
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59. What kind of file is this? The following 4 transparencies are a quotation from http://hul.harvard.edu/gdfr (see below).
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62. Repository Format Dependencies Using the OAIS Reference Model Global Digital Format Registry DSpace User Group, March 2004
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64. File format registries - URLs PRONOM : http://www.nationalarchives.gov.uk/pronom/ (does not only rely on extensions) Global Digital Format Registry : http://hul.harvard.edu/gdfr (predominantly project description) FileExt : http://filext.com (predominantly links to software)
65. Exercise I: A few experiments Group 1 Aist ė Abromaityt ė Tomasz Jablonski Aadi Kaljuvee Jurat ė Kuprien ė Violeta Meiliūnait ė
66. Exercise I: A few experiments Group 2 Libor Coufal Edvardas Germanas Hamid Rofoogaran Laima Šiudikiene Egl ė Žvinyt ė
67. Exercise I: A few experiments Group 3 Renata Balandien ė Thomas Guignard Edgars Jekabsons Elona Malaiškien ė Bjorn Ragnolf Ronning
68. Exercise I: A few experiments Group 4 Gražina Deveikyt ė Raimondas Malaiška Filip Kwiatek Marija Prokopčik Piret Randmae Jelena Saikovič
69. PART II – Formats in PLANETS: File characteristics
77. Computer science does not really know what information is. It is pretty good at representing and processing it, though.
78. Representations & migrations III == 3 == γ ‘ == ●●● Four representations of the idea / concept / model three
79. Representations & migrations I divided by III == 1 / 3 == 1.3333? I divided by III == 1 / 3 == 1.3 periodic Some ideas are handled more precisely by Some thinkers than others.
80. Representations & migrations 48 bit images on 24 and on 48 bit graphics cards. Some data is processed more adequately by some equipment than others
81. Representations & migrations A model for information before and after a migration must therefore potentially represent all information there, irrespective of the possibility to process it in a given environment.
82. XCEL / XCDL Languages are being processed … … development focus currently: dynamic handling of format specific algorithms.
83. XCEL / XCDL: image model (1) A pixel cube … Each pixel: MSB (channel 1), … LSB (channel 1), … MSB (channel n), … LSB (channel n), MSB (aux 1), … LSB (aux 1), … MSB (aux m), … LSB (aux m)
84. XCEL / XCDL: image model (2) A pixel cube … Accompanied by rendering info plus deployment info.
86. XCEL / XCDL: text model A text (= <object>) is composed of - data (<normData>) plus - interpretations of data according to the underlying format specification (=properties; <property>).
87. XCEL / XCDL: text model - example This is a text <refData id="1">54 68 69 73 20 69 73 20 61 20 74 65 78 74</refData> … <property> <name>fontsize</name> <rawVal> <val>00 18</val> <type>unsignedInt8</type> </rawVal> <dataRef> <!-- property refers to discrete part of reference data- -> <ref id="1" start="0" end="3"/> <ref id="1" start=“10" end="12"/> </dataRef> </property>
88. Exercise II: Abstract modelling Group 1: maps Group 2: music Group 3: excel sheets Group 4: „books“ … ever heard of FRBR?