Dynamic Web File Format Transformations with

Grace

Daniel S. Swaney, Frank McCown, and Michael L. Nelson

Old Dominion University

Computer Science Department

Norfolk, Virginia, USA

IWAW05September 23, 2005

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Time

XBM

Current browser accessible formats

GIF PNG JP2

PS PDF

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Time

XBM

Current browser accessible formats

Grace accessible formats

GIF PNG JP2

PS PDF

Date last modified: 2000-03-20

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Related Work

Typed Object Model (TOM) TOM Conversion Service

http://tom.library.upenn.edu/convert/ JSTOR/Harvard Object Validation

Environment (JHOVE)http://hul.harvard.edu/jhove/

LOCKSS (Lots of Copies Keep Stuff Safe)http://lockss.stanford.edu/

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High Level Design

Web Server GraceTranslation

Service

Redirect all Web Trafficto a Proxy

Server

www.odu.edu

ClientWeb

Browser

Http Request

Http Response Http Response(Translated

if necessary)

Http Request

Internal TranslationSoftware

ExternalTranslation

ModuleRemote

Translation Server

TranslationRules

Translation RulesManager

End-UserÕs Machine

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Configuring Grace

End-User

Profile- Uniquely identifies a user or group of users’ preferences

- Contains a list of one or more transform rules to follow

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Configuring Grace

End-User

Profile

- Rules for converting one type into another

- Example:image/x-xbitmap image/png

- Multiple transformations can be performed on the sameobject

Transform

Transform

Transform

…

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Grace in Action

1. Test formats that are commonly available by most web browsers.

2. Test the PNG format that is improperly displayed by a variety of web browsers.

3. Test the JPEG 2000 format which can only be displayed using a browser plug-in.

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XBM Format

http://entropymine.com/jason/testbed/imgfmts/

image/x−xbitmap image/png

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PNG Format

Correct rendering IE rendering Grace conversion (lossy)

http://www.ecs.soton.ac.uk/˜njl98r/png-test/alpha/cmap.html

image/png image/bitmap

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JPEG 2000 Format

image/jp2 image/jpeg

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Future Work

Additional types of transformations TOM conversion service

Improve file format metadata JHOVE

Faster translation of Web content Cache conversions Convert before accessing

Scalable network of Grace servers OAI-PMH used for communication

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Future Work

Find missing Web content archive.org Search engine caches

Translation rules based on browser capabilities Discover what transformations are needed

Transformation Metadata How will the user know something has been transformed? Will they want to know?

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Thank You

Questions?Slides:

http://www.cs.odu.edu/~fmccown/research/grace/