[Digikam-devel] Image Metadata extraction : implementation progress...

[F.J.Cruz]

El Martes, 28 de Febrero de 2006 14:08, Gilles Caulier escribió:
> Le Mardi 28 Février 2006 12:22, F.J.Cruz a écrit :
> >
> > Of course,I'm very interested on metadata support in digiKam, especially
> > NEF files since I'm owner of a D50.In fact, along this last week I've
> > been having a look to exiv2 code and I want to make you some questions:
> >
> > - How are you going to implement metadata infor for files that are not
> > implemented in exiv2 yet?
>
> The better way that i have identifed to add better RAW file support is to
> re-use implementation from ExifProbe project :
>
> http://www.virtual-cafe.com/~dhh/tools.d/exifprobe.d/exifprobe.html
>
> I think that only a simple exif/markernote extraction is enought in digiKam
> at this moment.
>
> > Actually exiv2 has support only for CRW files
> > (one of the two Canon RAW formats, the other one is CR2), altough there
> > are files with makernotes specifications for a lot of manufacturers, so
> > if I want to implement metadata extraction for NEF files, have I to
> > implement the equivalent to crwimage in Exiv2? this can be a hard work if
> > we have to do this for all the manufacturers who provide RAW format.
>
> The ExifProbe have a very well documentated source code about. Each file
> format is separated cleanly. I think we can trying to use it.
>
> Each Digikam::DMetadata::loader are separate too. We can add new image file
> format loader progressivly without any risk.
>

I want to write this stuff for nef files, but I need you give me some tips 
about how to implement it (following the ideas  you described up)

> > - What's about "write-access" on iptc data?
>
> With Exiv2 you can write IPTC tag in image, CRW included.
>
> > - Which of all  these changes are for 0.9.0?
>
> Right question. I need any report about my patch with the current
> implementation before to commit anything.

About the new exif/makernotes/iptc viewer looks fine but there is a lot of 
work to do and not only for other raw files. There is some fields and a lot 
of values that are not in "human-readable" format so we need  a "dictionary" 
to translate this stuff to something that anybody can understand. If we have 
exiftool as reference, you can understand what I'm talking about.

So if you give me some tips, as I've said, I can start to implement metadata 
stuff for nef files (or other files format you want), until we have a final 
decision about color management issue.

Paco.