[digiKam-users] Metadata for RAW files

[James Orr]

I think it is important to recognize that XMP sidecar files are at heart 
text files formatted in a particular, specifically defined format. 
Virtually any pure text editor can be used to edit the files. DigiKam 
enables certain ways to create edit xmp files. These methods also link 
to the DK database, which is useful.

SourceForge has a number of editors, see: 
https://sourceforge.net/directory/os:windows/?q=exif+xmp+editor

One can also use various code editors such as notepad ++, Microsoft's 
advanced notepad. See here for reviews of other options: 
https://www.keycdn.com/blog/best-text-editors
https://www.guru99.com/notepad-plus-plus-alternative.html

When venturing into these domains, one must accept the risks of one's 
errors of omission and commission, and limits of understanding.

I've recently made several hundred Canon RAW CR2 files. I have used DK 
to create XMP sidecars for each of them. My project is to copy several 
hundred images from my slide catalog dating from long ago until the 
1990's or so. My process is to photograph each slide with three 
bracketed exposures approximately -1 EV, +1 EV, and +3 EV. I use another 
software package to create HDR images which are saved as tif images 
(about 140-150 MB each). The sidecar data are not carried through from 
the CR2 folder to the HDR folder, so I copy and paste the data for each 
image. The HDR folder does not have sidecar files.

I have examined the XMP sidecars with Notepad ++, and have not changed 
anything in them.

It seems to me that DK is adequate for my needs.


James M. Orr 2705 E Sussex Way Fresno, CA 93726
On 6/23/2019 3:23 PM, Andrew Goodbody wrote:
> Gilles,
>
> I think you are not understanding what Rafael is asking. He knows that 
> raw files are not to be modified. He has enabled sidecar support. He 
> only wants to edit the metadata that is stored in the database and in 
> the sidecar file.
>
> Andrew
>
> On 22/06/2019 14:10, Gilles Caulier wrote:
>> Even if RAW files are mostly based to TIFF/EP standard, there are 
>> plenty of proprietary chunk/tags/container included in the tree of 
>> file and it's a very bad idea to try to write RAW metadata in file. 
>> RAW files must be considerate as read only and XMP side car used 
>> instead.
>>
>> Best
>>
>>
>> Gilles Caulier
>>
>> Le sam. 22 juin 2019 à 12:48, Rafael Linux User 
>> <rafael.linux.user at gmail.com <mailto:rafael.linux.user at gmail.com>> a 
>> écrit :
>>
>>     Metadata I want to change it's not photo parameters related, but
>>     "Autor", "Credits", "Copyright" .... and so on. I have activated
>>     "read" and "write" to "Element and in XMP sidecar", and I understand
>>     in RAW files case, it should be write only to XMP files, not inside
>>     RAW files, that's fine.  Despite that, I only can change or "enable"
>>     checkboxes when over non RAW files. In this screenshot, you can see
>>     I selected a RAW file and try to change the "Credits" ... no option
>>     to do nothing about it.
>>
>>     image.png
>>     However, if I select a TIFF file, I can enable/disable and write
>>     metadata for "Credits".  :(
>>
>>     El vie., 21 jun. 2019 a las 17:50, Remco Viëtor
>>     (<remco.vietor at wanadoo.fr <mailto:remco.vietor at wanadoo.fr>>) 
>> escribió:
>>
>>         On vendredi 21 juin 2019 13:42:53 CEST Rafael Linux wrote:
>>          > As I always work from RAW, I would like to document my RAW
>>         files metadata
>>          > so, when creating exported versions of these RAW files, the
>>         metadata
>>          > automatically spread to the new files. However, I can edit
>>         metadata for my
>>          > RAW files from Digikam, and I guess it will be saved to XML
>>         files.
>>
>>         It depends on which metadata you want to change. Certain items
>>         should not be
>>         changed (e.g. original creation date, photographic information
>>         like F-stop,
>>         shutter speed, ISO setting), others should be written only once
>>         (creator...),
>>         and some aren't really useful on a raw file, or can change for
>>         every export
>>         (e.g. licensing info).
>>
>>         Also note that saving to XML files is optional, and writing to
>>         raw files is
>>         strongly discouraged. So if you have both "writing to raw" and
>>         "writing to
>>         sidecar XMP files" disabled, dk can't save the metadata other
>>         than to its
>>         database (which is done in any case).
>>
>>          > The fact
>>          > is that I can access to "Edit metadata", but I can't change
>>         the info.
>>          > Is a nonsense what I pretend or there is another way to do
>>         what I want?
>>
>>         I suppose you noticed that, in the "edit metadata" dialog, a lot
>>         of items have
>>         to be explicitly enabled by clicking a checkbox...
>>
>>
>>
>>         Remco
>>
>>