[Digikam-users] Pentax PEF vs DNG in digikam

Gilles Caulier caulier.gilles at gmail.com
Wed Sep 28 09:06:06 BST 2011

2011/9/28 Karl Günter Wünsch <kgw at mineralien-verkauf.de>:
> On 09/28/11 09:10, Gilles Caulier wrote:
>> The problem is raw processor (libraw), which do not use this backup
>> properly for the moment.
> That backup is worthless in this context as the DNG specification
> mandates that the RAW processor is supposed to work solely on the
> transcribed subset of maker notes.

yes, but it's impossible to translate all" undocumented" makernotes
from all camera makers to the uncomplete list of DNG makernotes

So a copy of standard Exif makernotes byte-array from RAW to the
standard Exif makernotes byte-arry to DNG is the safe solution for the

>> At least NO data are lost in DNG
> Maybe in the version you programmed behaves like that but what about the
> Adobe one? I have tried DNG back when I still had a Canon 30D - with the
> result that the Adobe converter botched the conversion badly.

Agree. I tried too, and Adobe try to re-invent the broken wheel. Adobe
cannot reverse-coding all makernotes from all camera makers and models
to convert to the dedicated transcryted tags. It's a way to update DNG
converter for a life. Really a bad solution.

> But even with fully backed up meta data, can you reverse the process and
> recreate the original file if you didn't embed it fully?

makernote is saved as well. So it can be restored. But you cannot
recreated full RAW file of course.

The goal to backup makernotes is for the future improvements of Raw
processor, which will use these info as well in demosaicing.

Gilles Caulier

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