[Digikam-devel] XMP to solve tags name and Tags Path record in pictures metadata...

[Mikolaj Machowski]

Dnia poniedziałek 01 październik 2007, Gilles Caulier napisał:
> 2007/10/1, Mikolaj Machowski <mikmach at wp.pl>:
> > Dnia poniedziałek 01 październik 2007, Gilles Caulier napisał:
> > >     xmlns:dc="http://purl.org/dc/elements/1.1/"
> > >     xmlns:digiKam="http://www.digikam.org/"
> >
> > Shouldn't path be more precise?
> Excepted for digikam.org, where we can host a dedicaced page where users
> can found the descrition of the provate schema, all others are official
> and provided by specifications from adobe. For all request please mail
> to Adobe support (:=)))

Well, I was commenting on digikam.org,  the  rest was left as comparison
(all the 1.0, 1.1 ;)

> > > But i have a question about how to save the a tag path. Currently
> > > the separator is a '/'. This can be a problem if user use this
> > > character in a tag name because it will break the tags tree in a
> > > future import (backup/restore). If somebody has an alternative to
> > > prevent this problem, let's me hear...
> > >
> > > Thanks in advance for you constructive remarks...
> >
> > Maybe some "phishing"?
> >
> > Unicode provides several types of slash, among them:
> >
> > 2044    ???     FRACTION SLASH
> > 2215    ???     DIVISION SLASH
>
> This can be fine.

Hmm. See below.
>
> Comparing to well known solidus:
> > 002F    /       SOLIDUS
> >
> > Since XMP fully supports utf-8 we could use them. But there is one big
> > problem (as seen above): we may be not sure if user has font with
> > proper glyphs. Of course it is possible to do some display time
> > substitute but with that it would be probably better to use some
> > special sequence of chars, beginning eg with :: and ending with {%this
> > is digikam tags path separator%} :)
>
> no; the separator is never displayed somewhere in digiKam it used
> internally to "separate" all branches of the Tags Album treeview. In
> fact the right separator char must be used to not be confused with the
> real text (Tag names)

In that case it is probably better use really different path separator
(as arrow below) or just plain ASCII where :: seems favorite :)

> > Well, after a moment of thinking... why stop at phishing-like
> > solutions? Just use real arrows:
> >
> > 279D    ???     TRIANGLE-HEADED RIGHTWARDS ARROW
> >
> > I put it in some random string in libksirtet.po and works quite nice
> > on my system.  While I am working on KDE from SVN (3.5 branch), and Qt
> > 3.4.3 the rest of my system is 2 years old - including fonts.
> >
> > If you prefer good old ASCII:
> > :: - geek friendly, may be not so understandable for "masses"
>
> I love this one. It's like C++ namespace. I think it's not used with
> natural languages. Someone can confirm ?

>> Feature wish: auto synchronisation of appropriate  digiKam tags with
>> more common XMP schemas like DC, or IPTC Core.
>
> Already don in svn (:=))) Just missing 2 methods to sync Exif/Iptc with
> Xmp, because Xmp can host all standard Exif/Iptc tags.
>
> The only tags witch cann ot be sync is makernote. A possible solution is
> to host markernotes byte array as binary string in a dedicaced Xmp tag.
> but it doesn't exist in norm. 

Binary XML is evil ;) As you wrote in several occasions (in
apprehension) - leave Makernotes as they are and don't touch them 
if not really necessary.

Personally I am interested *exclusively* in contextual metadata like
covered in Dublin Core and IPTC Core.

> The way to save markernot in Xmp is
> important, especially with TIFF file format. libtiff is weird to
> handle/manage all Exif tags. When we convert a RAW file to TIFF, all
> Exif/Markernotes tags diseapear. Until than Exiv2 support tiff writing
> mode, this can be an alternative...

Maybe Andreas could tell how distant is future of full support of
metadata in TIFF - if not very maybe better is to leave this out from
Digikam?

m.