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From Jens Grivolla <j+...@grivolla.net>
Subject Re: big offsets efficiency, and multiple offsets
Date Thu, 05 Dec 2013 09:04:24 GMT
I agree that it might make more sense to model our needs more directly 
instead of trying to squeeze it into the schema we normally use for text 
processing.  But at the same time I would of course like to avoid having 
to reimplement many of the things that are already available when using 
AnnotationBase.

For the cross-view indexing issue I was thinking of creating individual 
views for each modality and then a merged view that just contains a 
subset of annotations of each view, and on which we would do the 
cross-modal reasoning.

I just looked again at the GaleMultiModalExample (not much there, 
unfortunately) and saw that e.g. AudioSpan derives from AnnotationBase 
but still has float values for begin/end.  I would be really interested 
in learning more about what was done in GALE, but it's hard to find any 
relevant information...

Thanks,
Jens

On 04/12/13 20:16, Marshall Schor wrote:
> Echoing Richard,
>
> 1) It would perhaps make more sense to be more direct about each of the
> different types of data.  UIMA "built-in" only the most "popular" things - and
> Annotation was one of them.
>
> Annotation derives from Annotation-base, which just defines an associated Sofa /
> view.
>
> So it would make more sense to define different kinds of highest-level
> abstractions for your project, related to the different kinds of views/sofas.
> Audio might entail a begin / end style of offsets;  Images might entail a pair
> x-y coordinates, to describe a (square) subset of an image.  Video might do
> something like audio, or something more complex...
>
> UIMA's use of the AnnotationBase includes insuring that when you add-to-indexes
> (an operation that implicitly takes a "view" - and adds a FS to that view), that
> if the FS is a subtype of AnnotationBase, then the FS must be indexed in the
> associated view to which that FS "belongs"; if you try to add-to-index in a view
> other than the one the FS was created in, you get this kind of error:
>
> Error - the Annotation "{0}" is over view "{1}" and cannot be added to indexes
> associated with the different view "{2}".
>
> The logic behind this restriction is:  an Annotation (or, more generally, an
> object having a supertype of AnnotationBase) is (by definition) associated with
> a particular Sofa/View,  and it is more likely that it is an error if that
> annotation is indexed with a sofa it doesn't belong with.
>
> Of course, Feature Structures which are not Annotations (or more generally, not
> derived from AnnotationBase), can be indexed in multiple views.
>
> 2) By keeping separate notions for pointers-into-the-Sofa, you can define
> algorithmic mappings for these that make the best sense for your project,
> including notions of fuzzyness, time-shift (imagine the audio is out-of-sync
> with the video, like lots of u-tube things seem to be), etc.
>
> -Marshall
>
>
> On 12/4/2013 9:31 AM, Jens Grivolla wrote:
>> Hi, we're now starting the EUMSSI project, which deals with integrating
>> annotation layers coming from audio, video and text analysis.
>>
>> We're thinking to base it all on UIMA, having different views with separate
>> audio, video, transcribed text, etc. sofas.  In order to align the different
>> views we need to have a common offset specification that allows us to map e.g.
>> character offsets to the corresponding timestamps.
>>
>> In order to avoid float timestamps (which would mean we can't derive from
>> Annotation) I was thinking of using audio/video frames with e.g. 100 or 1000
>> frames/second.  Annotation has begin and end defined as signed 32 bit ints,
>> leaving sufficient room for very long documents even at 1000 fps, so I don't
>> think we're going to run into any limits there.  Is there anything that could
>> become problematic when working with offsets that are probably quite a bit
>> larger than what is typically found with character offsets?
>>
>> Also, can I have several indexes on the same annotations in order to work with
>> character offsets for text analysis, but then efficiently query for
>> overlapping annotations from other views based on frame offsets?
>>
>> Btw, if you're interested in the project we have a writeup (condensed from the
>> project proposal) here:
>> https://dl.dropboxusercontent.com/u/4169273/UIMA_EUMSSI.pdf and there will
>> hopefully soon be some content on http://eumssi.eu/
>>
>> Thanks,
>> Jens
>>
>>
>
>



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