[Digikam-devel] [Bug 103176] 16bit/channel framework for digikam

[Thorsten Schnebeck]

> ------- Additional Comments From caulier.gilles free fr  2005-11-06 20:19
> ------- To clarify any points about my current jobs in digiKam, these are
> fresh new about 16 bits/color/pixel and RAW files support :
>
> 1/ RAW file support in 8 bits/color/pixel complete on my computer. showfoto
> and image editor can load (not save) all RAW file format supported by dcraw
> program. I have also fixed parsing code to identify RAW files with current
> dcraw::parce.c implementation. This is fix any problem with DNG file
> format. This code is ready to commit. I will done it after 0.8.0 release
> date planed to november 15.

Are there more infos about digikams way to this future? Cause this is a 
fundamental change this sounds like a 0.9 trunk. Goes current 0.8.x after 
release in maintenance mode (bug fixing only)? Are there plans for a KDE 4 
port?

> 2/ DImage is currently in development and based on Renchi Raju
> implementation : - RAW files can be loaded in 16 bits/color/pixel using
> dcraw.

Cause there are now some project developing this RAW file loading code do you 
see any room for collaboration? ufraw use its fork, Krita has now dcraw.c in 
repository, too and of course there is the original code of Dave Coffin.
There are some alternative libs for for decoding and demosaicing but dcraw is 
somehow still in the lead.
I can ask him on the rawfile ML if he has any interests in creating or 
supporting a lib-style structure that is better suited for this task? Or is 
it better for digiKam here to create its own way?
  
>   - TIFF files can be loaded in 8/16 bits/color/pixel.
>   - PNG files can be loaded in 8/16 bits/color/pixel
>   - JPEG files can be loaded and saved in 8 bits/color/pixel. All metadat
> are preserved (JPEG/IPTC/COM). - ALL others image file format are loaded
> using QImage interface in 8 bits/color/pixel. - TODO  :
>        * writing save PNG/TIFF methods
>        * writing load/save PNM methods in 8/16 bits/color/pixel.
>        * writing save digikam comments in PNG and PNM (like with JPEG
> files) * Metadata support for TIFF file (IPTC).

As I wrote as comment in Toms blog:
The problem is, that we need a good support for writing a 16bit image format 
including transfer of metatags. Using RAW as digital negative is IMHO a wrong 
approach. Better use a common 16bit format like tiff, png or dng (tiff-like). 
For transfering metatags from raw to the processed image type my 'rawimage' 
kfile plugin shows a pragmatic solution until exiv2 is ready do fancy stuff 
like this.
  
>        * image editor and showfoto intergration (acutally DImage works with
> a dedicaced small image viewer based on image editor canvas).

Here I see also a conversion part as you can not show 16bit pics on a monitor 
(or printer(?)) Maybe it would be wise to make there a strong separation so 
that it would be possible to support color management in a remote future.

> * Fixed all 
> image filters in digikam/libs to support 16 bits/color/pixel. * Fixed all
> image plugins in digikam core and DigikamImagePlugins to support 16
> bits/color/pixel.

Yes, that is the hard-working part

> ... And that all for 0.9.0 release (outch...)

Ah, I see this answers a part of my question on top of this mail :-)

>
> If there are any volonters to help me in this large task, please let's me
> hear...

I really would like to step in. But you are one of this fast programmers that 
I feel inadequate in being a help. But you know that I have strong interests 
as power user in digikam image processing part. Do you see a chance to step 
in for a person like me with so limited time, less KDE background and no 
knowledge about digiKams code? :-) 

Bye

  Thorsten