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Re: Fragment identification

From: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Date: Thu, 12 Apr 2007 19:55:20 +0200
Message-ID: <461E7287.FC7A29C6@cwi.nl>
To: "Jeff Z. Pan" <jpan@csd.abdn.ac.uk>
CC: MMSem-XG Public List <public-xg-mmsem@w3.org>

Hi Jeff,

> Continuing the discussion on fragment identification from the telecon, I
> think we can mention the different approaches and provide some pointers
> for more details. What do you think?

I would say it will not be enough (even though it depends on what you mean by giving pointers)
Being able to localize part of MM is multimedia is fundamental for annotating it. This problem is
well-known and addressed in the litterature, and present in several use cases!
What I propose is that in the section 3.1, you dedicate a complete subsection dealing with this
problem (refering to the use cases when it is necessary), that is, recapitulate the various syntactic
possibilities with examples (each example just take 3-4 lines) and show the differences of the
approach (MPEG-21 vs MPEG-7 vs SVG vs TemporalURI, etc.).
You should also integrate a summary of the interesting discussion that is going on about the use of
CURIEs, see all the emails that have been spammed recently on the list :-) It is clearly on topic too!

I insert the message I wrote some time ago about this issue. For me, all the pointers are there and in
the associated thread. What you have to do is summarize all the issues and discussions ...

The message below complements my answer.
Hope that helps.


RaphaŽl Troncy a ťcrit :

> Dear Susanne,
> So below you address a very common problem that fortunately has been quite
> discussed in the litterature and several solutions have been proposed.
> First, I have partially answered to your problem in [1].
> A detailed answer is given below.
> > the problem is the following. Imagine that I use RDF to describe
> > a resource such as an image. How to I model in RDF that I
> > want to refer to a fraction of this image. This might be needed
> > if want to express the following.
> >
> > Subject (Susanne) - Predicate (is_the_person_in) - Object (rectangle
> > in an image)
> So, as I said, your problem is not RDF, is how to localize and uniquely
> identify a region of a multimedia document (you give the analogy in the
> SMIL world). That has nothing to do with RDF and is more linked to a URI
> problem (see below).
> This problem is slightly discussed in [2] (section 3) but extensively
> addressed in [3, 4] and particularly [5]!
> In short, you can imagine several tricks to solve your problem.
> 1/ Using SVG bounding box mechanism:
> This is what PhotoStuff is doing! In other words, you define a region using
> an SVG snippet, you can even add an anchor name, so the region is then
> identified and your RDF annotation will be "about" this anchor. You can
> find an example at [6].
> 2/ Using MPEG-7:
> Again, you create an MPEG-7/XML file (identifiable by an URI) that contains
> the definition of your region. Here, you have all the expressivity of
> MPEG-7, that is, the possibility of creating non-spatially connected region
> (mask in MPEG-7), typing your region (ellipse, rectangle, polygon, defined
> with exotic mathematical transformation, etc.) ... and again, your (RDF)
> annotation will be about the URI fragment defining this region (i.e. the
> XML portion of this file).
> Both solution introduces an indirection. Your annotation is not "about" the
> media itself but "about" an XML file that defines a region in a media. Note
> that for defining Temporal interval of video or audio document, a nice
> proposal named TemporalURI is on the table and I would strongly encourage
> to use it! The apache module server even exists to serve you only the video
> bits corresponding to the time interval you specify in a URI (not the whole
> video!). I would say this a clean solution and I'm all in favor to develop
> the SpatialURI based on the same model ...
> Best regards.
>     RaphaŽl
> [1] http://lists.w3.org/Archives/Public/public-xg-mmsem/2007Mar/0010.html
> [2] http://www.w3.org/2005/Incubator/mmsem/XGR-image-annotation/
> [3] http://ftp.cwi.nl/CWIreports/INS//INS-E0308.pdf
> [4] http://ftp.cwi.nl/CWIreports/INS//INS-E0309.pdf
> [5]
> http://www.uni-koblenz.de/~aggrimm/arbeitsberichte/arbeitsberichte_4_2007.pdf
> [6]
> http://www.w3.org/2005/Incubator/mmsem/meetings/f2f-amsterdam/multimedia/annotations/jacco_try.rdf
> [7] S. Pfeiffer, C. Parker, and A. Pang. Specifying time intervals in URI
> queries and fragments of time-based Web resources. Network Working Group,
> Internet-Draft, 2005. http://www.annodex.net/TR/URI_fragments.html.

RaphaŽl Troncy
CWI (Centre for Mathematics and Computer Science),
Kruislaan 413, 1098 SJ Amsterdam, The Netherlands
e-mail: raphael.troncy@cwi.nl & raphael.troncy@gmail.com
Tel: +31 (0)20 - 592 4093
Fax: +31 (0)20 - 592 4312
Web: http://www.cwi.nl/~troncy/
Received on Thursday, 12 April 2007 17:56:18 UTC

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