[KimDaBa] Writting EXIF *to* files

[G]

Shawn Willden a écrit :

>On Thursday 29 December 2005 07:09 am, G wrote:
>  
>
>>Jesper K. Pedersen a écrit :
>>    
>>
>>>So where do you all want category information written? Does any other
>>>application you use, read category information from a specific EXIF field?
>>>or should it just be put into the description field?
>>>      
>>>
>>For your question about metadata, maybe (it's my opinion, but I'm not
>>alone...) EXIF is not the best place to put informations about
>>categorizing...
>>
>>Aren't IPTC, or better XMP, preferable ???
>>    
>>
>
>I had never heard of IPTC or XMP prior to this post, but I did a little bit of 
>research and it seems to me that IPTC is specifically designed for exactly 
>this kind of metadata.  As I understand it:
>
>o  EXIF holds information about the technical characteristics of the image 
>file.  File name, camera, shutter speed, lens and flash configuration, 
>date/time, orientation, etc.
>
>o IPTC holds information about the content of the image.  Caption, keywords, 
>categories, etc.  IPTC can also hold lots of what's stored in EXIF.
>
>o XMP holds everything, including all the stuff no one has thought of yet.
>
>IMO, it makes a great deal of sense for Kimdaba to use IPTC for storing 
>category, keyword, etc. metadata.  Not only is IPTC designed to manage 
>exactly the sort of data that KimDaBa would like to store, the library 
>KimDaBa uses to manage EXIF data already supports IPTC.
>
>XMP, on the other hand, looks very powerful, but it also looks like a great 
>deal of work.  Perhaps it wouldn't be too bad to only support a small subset 
>of XMP -- maybe some of the Dublin Core schema, some of the Photoshop Schema, 
>the Camera Raw schema and the EXIF schema.  It might even make sense to add a 
>custom schema that allows all Kimdaba-managed metadata to be stored in the 
>image.
>
>XMP seems like a large, long-term project, though.  IPTC looks to be 
>accessible and well-suited to the immediate goals, and a better idea than 
>trying to find some EXIF tag that can be abused to hold category data.
>
>Just my two cents,
>
>        Shawn.
>  
>
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>
OK. Just to complete information about IPTC/XMP and their relative 
features/weaknesses. It's from the pixvue FAQ 
(http://www.pixvue.com/support/faq.html#1.5) :

> 5. What's the difference between IPTC & XMP?
>
> IPTC is a legacy standard that is supported by many applications. XMP 
> is a newer standard that addresses some of the shortcomings of IPTC:
>
>     * XMP is based on standards such as XML and RDF.
>     * XMP is interchangeable in a way that IPTC never can be.
>     * XMP is very extensible. New property values are simple to add 
> and in such a way as to remain completely compatible with all XMP editors.
>
> PixVue updates IPTC so as to maintain compatibility with legacy 
> applications that don't yet understand XMP.

But if supporting XMP is much more complicated as Shawn explained, and 
if EXIV2 exif library choosed by Jesper support IPTC out of the box, 
IPTC could be indeed a good choice...

Gérard.