[Digikam-users] DNG (was Re: LightZone)

[Fabien]

Hi,

I don't know if it could be useful, but I started recently to use chdk
firmware in my ixus 800is :
http://chdk.wikia.com/wiki/Main_Page
http://chdk.wikia.com/wiki/SD700_CHDK_Porting

This allows me to add features to the camera as bracketing (really great
to make HDR photos) and raw.
The raw file can be processed by dcraw (and so digikam and other tools
based on dcraw). But, there's also a converter to DNG format :
http://dng4ps2.chat.ru/index_en.html

It creates files that are slightly smaller than the original raw file,
but not sure if it's so different than the dcraw output...


Gilles Caulier wrote:
> 
> - DNG sdk is published using a restricted licence, non-opensource
> compatible. Look here :
> 
> http://www.adobe.com/support/downloads/dng/dng_sdk.html
> 
> - Linux is not supported in this SDK. Of course to have take a look in
> source code, this can be fixed without too many problem.
> 
> - Abode policy is really strange. Why XMP sdk is published with BSD
> license and support Linux as well, and not DNG sdk (:=(((
> 
> - Only DNG specification are published over the world.
> 
> In the pass, i have work on a patch for libkdcraw to convert RAW to
> DNG... in linear mode. This is bad way. There is 2 DNG storing image data :
> 
> 1/ RAW linear uncompressed (obsolete)
> 2/ JPEG LossLess with 16 bits color depth support (hightly recommended
> in DNG spec)
> 
> The first one can be done easily under digiKam, but size file are very
> huge (~2 or ~3x original RAW file size). This is a non-sense to use it...
> 
> The second one is the right way. File size are divided by 2. Problem :
> algorithm used by Adobe is strongly (c) and certainly covered by patents
> (i'm not sure about this point)
> 
> If you take a look over algorithm, it's an extended version of the old
> libjpeg for Linux ! Thanks to adobe to use opensource code and to make
> non-opensource implementations...
> 
> Another point is about OpenRaw stuff : It's a web site dedicated to
> promote DNG format as well... But DNG sdk is not open source
> compliant... This is why i will never support OpenRaw...

--
Fabien