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[Alaric Snell]
> On Friday 10 May 2002 13:53, Thomas B. Passin wrote:
>
> > True (see SOAP+attachmemts). XML is a good candidate for sending
> > metadata about binary data.
> >
> > As in MPEG-7, if I understand things right.
>
> But why does any data need to be 'binary'? XML is an interchange format,
but
> it falls apart for certain types of information such as images... large
> arrays and so on. Other interchange formats don't. You can encode images
in
> PER quite happily, it's just a "SEQUENCE OF SEQUENCE OF SEQUENCE { red
> INTEGER, green INTEGER, blue INTEGER }" from memory (might want to
constrain
> those R/G/B integers into a sensible range to make them one or two bytes
> each).
>
> Those giant arrays can fit seamlessly in with the "SEQUENCE OF Paragraph"
> describing the image to humans and the "ImageInformation ::= SEQUENCE {
name
> UTF8String, width INTEGER, depth INTEGER }" and be processed with the same
> tools. You can pull out the colour of the top left pixel of the image with
> what passes for XPath in ASN.1-land.
>
I don't know much about MPEG-7, but my impression is that the metadata they
want to deal with is much more ambitious than describing the number of lines
and frames. I think they want to describe more abstract characteristics of
scenes, and generally to be able to do SMIL-like things. These properties
don't seem to me to properly belong in with the image data. If this view is
roughly right, it makes a lot of sense to me to have the metadata separate,
just like it makes sense for card catalogs to be separate from books.
Cheers,
Tom P
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