[Digikam-users] Dynax 5D data (was SVN compile [solved])

[Thorsten Schnebeck]

Am Montag 02 Januar 2006 15:02 schrieb Caulier Gilles:
> Le Lundi 2 Janvier 2006 14:01, Belinda Martin a écrit :
> > On Monday, 2. January 2006 10:05, Thorsten Schnebeck wrote:
> > > Hmm, maybe I should add an action menu in Konqi to copy the
> > > metatags from raw over to png/jpg?
> >
> > Well that would be Christmas and Easter at the same time :-))
>
> Well copy exif information to jpg/png/tiff isn't a problem with
> Digikam::DImg API.

Is this part of the API already code? How do you transfer tiff 
tags to exif tags and vice versa? libexiv2? AFAIK these tags are 
not binary compatible(?)

I'm really really curious about, how you going to solve the 
problem of raw metadata transfer with dimg. I mean, I believe in 
you that you find a native solution. But I also know what a hard 
task this is.

>
> About PNG, the better way to save EXIF/IPTC metadata is to
> create a new bytes array saved in like a PNG tag. I will
> contact the PNG devel team to create new standard PNG tag
> relevant.
>
> This is want mean (for me) that PNG is the better soltion to
> backup JPEG/TIFF/RAW file without lost any metadata, like DNG
> file format (Adobe copyrighted) done, without require any
> additional library !!!
>
> What we want exactly :
>
> 1 / PNG support 16 bits/color/pixels. It's the perfect to
> backup RAW file image data.
> 2 / PNG support ICC color profile.
> 3 / PNG can embeded metadata using tags.
> 4 / PNG use a loss less compression algorithm without using any
> pattents ! 5 / PNG is GPL.
> 6 / PNG is a standard, DNG no.
> 7 / No need to use a new library. libPNG is enough and is
> present by default in all linux distro.
>
> My wiewpoint is that PNG is very adapted to save photograph and
> is more simple to use than JPEG or TIFF. A beeter support of
> PNG is my plan for the future...

Hmm, I would like to agree and I already use 16-bit-png as my 
personal digital negative. But serious, DNG will be the future. 
Its open, specs are open and Adobe "forces" the Photoshop users 
to transfer RAW files into DNG when using their RAW importer.
There are some digital backends for medium format that already 
save in DNG. Since 7.0 dcraw is redesigned for supporting DNG as 
reference for auto balance functions etc:
http://www.dpreview.com/news/0504/05042701davecoffininterview.asp
http://www.barry.pearson.name/articles/dng/products_y1.htm
http://www.adobe.com/products/dng/pdfs/dng_spec.pdf

But back to PNG. Software like imagemagick already use an enhenced 
tag definition, descibed here:
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PNG.html
(PNG TextualData Tag) These "Raw profile types" are not standard 
but very useful.

Bye

  Thorsten