This document summarizes technologies to support file format conversions for digital preservation. It presents three services: (1) a Conversion Software Registry to find conversion software between formats, (2) a File Conversion Engine to automatically execute conversions via third-party software, and (3) File Comparison Engines to evaluate information loss from conversions. These services aim to help archivists select preservation formats and evaluate conversion quality at scale. The document outlines related challenges and how the services address issues like software extensibility and computational requirements for large-scale conversions and comparisons.

1. e-Services to Keep Your
Digital Fil C
Di it l Files Current
t
Presented by: Peter Bajcsy
-Research Scientist at NCSA
-Associate Director of I-CHASS, I3
,
Institute
-Adjunct Assistant Professor, CS & ECE
UIUC
National Center for Supercomputing Applications
University of Illinois at Urbana-Champaign

2. Acknowledgement
• This research was partially supported by a National
Archives and Records Administration (NARA)
( )
supplement to NSF PACI cooperative agreement CA
#SCI-9619019 and NCSA Industrial Partners.
• The views and conclusions contained in this doc ment
ie s concl sions document
are those of the authors and should not be interpreted as
representing the official policies, either expressed or
implied, of the National Archives and Records
Administration, or the U.S. government.
• Contributions by: Peter Bajcsy Kenton McHenry Rob
Bajcsy, McHenry,
Kooper, Michal Ondrejcek, Jason Kastner, William
McFadden, Sang-Chul Lee, Luigi Marini
Imaginations unbound

3. Outline
• Introduction
• Technologies
• File format conversion software
registry
• Automated file format conversions
• Conversion quality assessment
• Summary
• Future Work

4. Introduction

5. Supporting NARA’s Strategic Plan
• According to The Strategic Plan of The
National Archives and Records
Administration 2006–2016. “Preserving the
Past to Protect the Future”
• “Strategic Goal: We will preserve and
process records to ensure access by the
public as soon as legally possible”
possible
• “Part D. We will improve the efficiency
with which we manage our holdings
from the time they are scheduled
through accessioning, processing,
storage, preservation
storage preservation, and public
use.”

6. To Preserve or Not To Preserve?
Digital representation of
information Preservation
& knowledge
Information
transfer ?
AGENCY ARCHIVES
Imaginations unbound

7. Do We Know the Answers?
• (1) What is the granularity of information that one
should preserve about a decision process in order to
reconstruct it?
• Example: the granularity of information collected
from a decision process based on visual inspection
of images has implications on storage and
computational requirements/costs
comp tational req irements/costs –
ImageProvenance2Learn (IP2Learn)

8. Do We Know the Answers?
• (2) Given thousands of DVDs with files, which
files are related?
• Example: given files that contain 2D scans of
blue prints and 3D CAD models, find the
p ,
content-based file correspondence - File2Learn
prototype system
Relationship Discovery
30 files 784 files

9. Do We Know the Answers?
• (3) Given hundreds of versions of the ‘same’ file,
which file version(s) are similar and which one(s)
should be preserved?
h ld b d?
• Example: given a collection of Adobe PDF
documents,
documents compare all pairs of Adobe PDF
documents containing text, images, vector
graphics,… and order them chronologically or
based on similarities - Doc2Learn prototype

10. Do We Know the Answers?
• (4) Given thousands of file formats, which
conversion software to use and which
target file format to use so that the
content of those thousands of files would
be viewable in a long run?
• Focus of today s talk is on examples
today’s
of technologies that would provide
answers to (4) at large processing
scale with computational scalability.

11. Goal
• Ob
Observation: Fil f
ti File format conversions are
t i
inevitably one part of our daily life
• Question: Can file format conversions assist in
making digital content created today to be
accessible and viewable throughout its
lifecycle?
• Consideration: we do not know what file
formats will be around 100+ years down the
y
road
• Goal: to make files backward and forward
compatible

12. Background on File Format Conversions
• A very large number of file formats in which digital content is
stored.
• A i
An increasing number of complex fil f
i b f l file formats containing
t t i i
multiple types of digital content (e.g., Adobe PDF, HDF) or
having very elaborate specifications (e.g., STEP).
• Many software implementations of import (read) and export
(write) operations.
• A wide spectrum of quality of software i l
id t f lit f ft implementations
t ti
when reading and storing content in various file formats.
• Ephemeral support for many file formats and software
implementations
• Hardware dependency of many software implementations

13. Illustration of 3D File Format Reality
*.ma, * b *
* *.mb, *.mp *.k3d
k3d
*.pdf (*.prc, *.u3d)
*.w3d
*.lwo *.c4d *.dwg *.blend *.iam *.max, *.3ds

14. Challenges and Objective
• Challenges:
• The quality of file format conversions is unknown when
using a particular software to do the conversion
• The volume of file format conversions requires significant
computational resources
• Understanding information loss due to file format
conversions is application dependent
• Estimating information loss is complicated due to the
complexity of file formats
• Th file f
The fil format, software and hardware d
t ft dh d dependencies are
d i
often unknown
• Objective: Design and prototype services using a
j g p yp g
computational cloud to support forward-looking decisions

15. Parameters of File Format Conversions
• File format: Content representation depends on a
file format
• Software: Retrieval and storage of content in a file
format depends on the quality of software
implementation
• Hardware: Software execution depends o access
a d a e So t a e e ecut o depe ds on
to storage media, operating system, and hardware
platform
• Criteria defining information loss: Information
loss due to file format conversions is defined by
application specific criteria

16. Three Example Services of Interest
• (a) Find file format conversion software
to convert from any file format to any
other file format
• (b) Execute file format conversions with
any available thi d party software
il bl third t ft
• (c) Evaluate information loss due to file
( )
format conversion over a set of files in
multiple complex file formats

17. Technologies

18. Overview

19. #1: Conversion Software Registry (CSR)
• Problem: Find file format conversion
software to convert from any file format to
any other file format
• Technology: Conversion Software Registry
(CSR) at
https://isda.ncsa.uiuc.edu/NARA/CSR/
https://isda ncsa uiuc edu/NARA/CSR/
• Features: Support for searching, editing and
adding i f
ddi information about fil f
ti b t file format
t
conversion software, open access and login-
based modification
b d difi ti

20. Movie of CSR

21. Comparison of CSR with Other Systems
• File Format Registries
• PRONOM developed by the National Archives of the United
Kingdom
g
• Unified Digital Formats Registry (UDFR – before GDFR)
• Software Registries/Catalogues
• C
Community specific
it ifi
• The Geotechnical and Geoenvironmental Software Directory
(GGSD)
• The Natural Language Software Registry (NLSR)
• Business oriented
• The Bit9 Global Software Registry (
g y (whitelisting software)
g )
• Cnet (available software with links to feature descriptions)
• File Format Conversion Registries
• Th Planets test bed (password protected, 18 software packages)
The Pl t t tb d( d t t d ft k )

22. Novelty of Conversion Software Registry
• Existing file format registries focus on file format
specifications
• Catalogues of software focus on software of interest
to a specific community and include information
about t level d
b t top l l description, vendors and price b t
i ti d d i but
not capabilities to import and export file formats
• A file f
fil format conversion registry lik Pl
t i i t like Planets.org
t
supports 16 software packages, only single-hop
conversion paths and couples software to the reg reg.
• Novelty: CSR provides answers about multi-hop
conversion paths from about 70+ software
70
packages currently
Two-hop conversion path

23. #2: File Format Conversion Engine
• Problem: Execute file format conversions
with any available third party software
• Technology: Polyglot version 1, operating
on NCSA hardware resources
resources,
downloadable for private deployment
• F t
Features: web-based access t a
bb d to
computational cloud consisting of
commodity h d
dit hardware and i t ll ti
d installations of
f
third party software with import/export
capabilities
biliti

24. Movie of Polyglot

25. Polyglot Design EXTENSIBILITY
AUTOMATION
Cloud Computing
COMPUTATIONAL
SCALABILITY
Services to Archivists

26. Comparison of File Format Conversion
Systems
• Some existing file format conversion services
• http://www.ps2pdf.com;
p p p ;
• Supports only certain conversion types
• http://www.zamzar.com
• Supports conversion of document, image,
music, video and couple of CAD formats
• http://media-convert.com
• Supports about 20 multi-media formats
• D
Drawbacks: Th existing systems are not
b k The i ti t t
extensible (limited by specific libraries), cannot be
downloaded for private use (files with sensitive info)
info),
computational scalability is unknown

27. Format Conversion Extensibility Via
Software Reuse
• Observation: Nobody has the resources to load every
possible file format
• Fully supporting the many available formats is an
enormous undertaking
• If a file format is closed/proprietary it may be difficult to
retrieve the data directly from the file
• Vendor file formats sometimes store application feature
pp
specific pieces of information that is not supported in
other formats
• M t software support importing/exporting of a subset of
Most ft ti ti / ti f b t f
application domain specific file formats.
• Conclusion: Software reuse a d e te s b ty are t e key
Co c us o So t a e euse and extensibility a e the ey
characteristics of file format conversion systems

28. File Format Conversion Extensibility
• Extensibility in Polyglot: Software is reused by wrapping
3rd party software while utilizing whatever access the
software vendors make available to embedded
f d k il bl b dd d
functionality
• published Application Programming Interface (API),
(API)
command line and Graphics User Interfaces (GUI)
• Novelty: Polyglot p
y yg provides a single user interface that
g
allows the user to execute multiple software conversion
software applications automatically, and over distributed
computers that have a license for the software needed to
do the conversion and/or have the computing resources
necessary for the size of the job (computational scalability).

29. #3: File Comparison Engines
• Problem: Compare two files and evaluate
information loss due to file format conversion over a
set of files in multiple complex file formats
• Technologies:
g
• Initial prototypes: ModelBrowser (four 3D
comparison metrics); Doc2Learn (one metric
across multiple digital objects), Doc2LearnHadoop
(computation scalability using Hadoop)
• Work-in-progress: A general API for content-based
comparison of any two files - Versus

30. 3D Comparison Example (ModelBrowser)
heart.stl
• Software: Adobe 3D Reviewer heart.wrl
h t l
• Original File: WRL
• Converted Files: STP, STL,
IGS, U3D
• Comparison Method: Light
Fields [C e , 2003] compares
e ds [Chen, 003] co pa es heart.stp
heart stp
silhouettes from various viewing
angles around the objects
Conclusion: Information loss(WRLSTP)=Information loss (WRLSTL)

31. Multiple Object Comparisons (Doc2Learn)
Adobe PDF documents ~ {text, images, vector graphics, ….}

32. Multiple Method Comparisons (Versus)
• Software: MS Paint
• Original File: TIF
• Converted Files: PNG, GIF, JPG, BMP
• Comparison Method: Pixel by pixel difference (sum of
Euclidean distances over all pixels)
User Inputs
Conclusion 1: Information loss(TIFBMP or TIFPNG) =0
Conclusion 2: Information loss(TIFGIF) > Information loss(TIFJPG)

33. Information Loss Evaluation
Setup:
• Inputs: a set of files, a set of software packages,
p p g
criteria for defining information loss
• Wanted output: information loss ‘score’ per file
format conversion
Approach:
• Phase I: Find all round-trip conversion paths from a
given file format to the same file format
• Phase II: Execute all conversions to obtain
converted files.
• Phase III: Compare the original and converted files

34. Information Loss Evaluation: Computational
Requirements
• Files: one file in STP file format
• Software: Adobe 3D Reviewer, Cyberware PlyTool
• Comparison Method: Light Fields [Chen, 2003]
• Number of paths: 10 (28 individual conversions)
Phase I: Find Phase III: Compare
Phase II: Execute

35. Summary

36. Information Technology Lessons
• Better understanding of preservation and reconstruction of
electronic records in terms of file format conversions
• Th data model needed f d
The d t d l d d for documenting existing fil
ti i ti file
format conversion software
• A framework (test bed) for software reuse and
extensibility to provide file format conversion services
• The complexity of performing content-based file
comparison and measurements of information loss d
i d t fi f ti l due
to file format conversions
• The computational cost of file format conversions, file
comparisons and information loss evaluations
• The computational scalability of file format conversions
and fil comparisons using parallel processing paradigms
d file i i ll l i di

37. The Value for Archivists
• Prototype services are freely available to digital preservation
community and provide decision support tools
• to select an ‘optimal’ file format to be preserved
• to evaluate file format conversion software
• to select minimum cost for a chosen file format conversion
path
• The framework for conversion software documentation, ,
software reuse and functionality extensibility has a major
impact on
• Effi i
Efficiency with which we manage our h ldi
ith hi h holdings
• Understanding of the information loss introduced due to
conversions
• The cost of updating file format conversion services

38. Development Plans
• Prototype services are open to the public at
• https://isda.ncsa.uiuc.edu/NARA/CSR/
• http://teeve3.ncsa.uiuc.edu/polyglot/convert.php
• Software is open source technology and
downloadable from
http://isda.ncsa.uiuc.edu/download/
p
• We have been building a second generation of
these file format conversion services
• Feedback is very welcome
• Questions: Peter Bajcsy –
j y
pbajcsy@ncsa.uiuc.edu