[Digikam-devel] libopenraw to support better RAW files in digiKam ?

[Gilles Caulier]

Le Jeudi 24 Novembre 2005 08:56, Thorsten Schnebeck a écrit :
> Am Mittwoch 23 November 2005 22:01 schrieb Caulier Gilles:
> > Le Mercredi 23 Novembre 2005 12:25, vous avez écrit :
> > > Am Mittwoch 23 November 2005 10:59 schrieb Gilles Caulier:
> > > > Le Mercredi 23 Novembre 2005 10:18, vous avez écrit :
> > > > > Am Mittwoch 23 November 2005 08:53 schrieb Gilles Caulier:
> > > > > > Hi all,
> > > > >
> > > > > Hi Gilles,
> > > > >
> > > > > > To investigate about RAW files support in digiKam, i
> > > > > > had found this link :
> > > > > >
> > > > > > http://www.freedesktop.org/wiki/Software_2flibopenraw
> > > > >
> > > > > Hubert Figuiere has a name in unix photo world
> > > > > http://www.teaser.fr/~hfiguiere/linux/digicam.html
> > > >
> > > > Yes, i now him (:=))). He's a French guy (:=)))
> > > >
> > > > > so this can be a good approach. OTOH this group has to be
> > > > > somehow better than Dave Coffin. A lib that supports file
> > > > > decoding, demosaicing and metatag decoding as an open
> > > > > project would be cool but in a sense creating and
> > > > > supporting such a lib is a little bit out of digiKams
> > > > > scope, or? digiKam wants to use such a lib.
> > > > >
> > > > > Browsing through
> > > > > http://cvs.freedesktop.org/libopenraw/libopenraw
> > > > > this seems to be a one person project and there is no
> > > > > usable code. The problem is, when Dave Coffin does not
> > > > > support such a lib you have to adjust/recreate the lib
> > > > > again and again with every release of a new dcraw.c.
> > > >
> > > > Yes, i have the same problem in digikam core, because i
> > > > have started to create a similar lib using dcraw program.
> > > >
> > > > > Maybe a better alternative can be a KDE wrapper for raw
> > > > > handling. That way we can collect all the stuff out there
> > > > > now, can use our own data types, can integrate I18n and
> > > > > if there is a better lib someday we only have to adjust
> > > > > the wrapper(?)
> > > >
> > > > well, i can use any code parts of libopenraw to improve my
> > > > current implementation for example.
> > >
> > > I dont think there is something in CVS that could improve
> > > anything ;-)
> > >
> > > > I'm so suprise that
> > > > libopenraw isn't updated since 4 months on repository.
> > > >
> > > > Perhaps you is interresed to help in this task ?
> > >
> > > I really like to help but how do you think we should start?
> > > Collaboration a la libobenraw or realizing first something
> > > workable and then anouncing this and ask for collaboration.
> > > Maybe the Krita-team is also interested?
> >
> > certainly, but i'm not favorable to create a shared lib
> > actually. I have no time to manage a new project like this. I
> > prefert limited developement to a local lib in digikam core
> > dedicaced only to digikam
> >
> > > That way we do not need to
> > > handle with cryptic glib C-code and can use pure Qt-C++ :-)
> > >
> > > You said you already have some libopenraw-like code?
> >
> > Just a code to check RAW file type and extract thumnails using
> > parse.c from dcraw
> >
> > I want add dcraw.c source code and add a new method to get raw
> > image data directly without using an external dcraw thread
> > using pipe for improve loading time in IE.
> >
> > I want too, add a method to get thumnails orientation. dcraw
> > have been added to kimdaba in this way but dcraw.c is completly
> > broken on.
>
> Hmm, I had that (type, thumbnail, rotation) already programmed but
> you dont liked that :-)

yes (:=)))

>
> > and finally, i want add a method get embedded meta data and ICC
> > profil.
>
> I do not know every raw format but what use embedded ICC profiles?
> In Canon world it is like this: Every JPEG works in calibrated
> sRGB color mode, but RAW is not adjusted to any mode. I only know
> TIFF and JPEG that have embedded ICC profiles often from
> Photoshop. You can extract these profiles with (of course)
> ExifTool:
> http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/ICC_Profile.html

No need to use external tool. DImg API do it nativly for JPEG, PNG, and TIFF. 
Already done on my computer. Other file format loader need to be done, like 
JPEG 2000, OpenEXR, and Krita. This will be done later. (any contributors 
welcome).

In all case, i'm not favorable to use PERL tool with C++, for any performances 
reasons especially. digiKam have been written in C++, not in Perl. 

To have look a little in dcraw, i have seen any RAW files provide an embedded 
ICC profil (Fuji Raw file for example)

>
> I have looked into dcraw.c - and dont like it ;-) Brrr. All in one
> and one for all. But using an extenal ICC profile with RAW data
> is already in there.

yes.

Gilles