[Digikam-users] Re: using extracted jpeg as "sidecar" for raw files

[Robert Zeller]

Hello Elle,

I am shooting both, jpg and raw (in my case Nikon .nef) files. Like you
I am storing the raw and the jpg files in different sub directories of
every album, sub dirs typically called jgp and raw. Since mostly the
jpg's are ok I do all the tagging on the jpgs and store the meta data in
the jpgs. After that is done, I extract the meta data from the jpgs
using exiv2: Typical command:
exiv2 ex *.jpg
; this creates sidecars with the jpgs basename and the extension .exv.
Then I move the .exv sidecar files to the raw subdirectory and write the
metadata to the raw files; using e.g. the following command sequence:

for F in `ls *.nef` ; do
exiv2 -iixe $F
done

the .exv files can be removed after that

you   can obtain all the exiv2 command options by:

man exiv2

Robert Zeller

On 01/06/2011 06:50 PM, Elle Stone wrote:
> Hello digikam users,
>
> I don't want to use dng. But I would like a way to tag, caption, etc my raw
> files. I was thinking of extracting the embedded jpegs and using them as a
> handy "side-cars" for the raw files for tagging, rating, etc. Has anyone
> done so? How did it work for you? Any reasons why it is perhaps not such a
> good idea?
>
> If the jpeg "side-car"carries all the metadata produced by digikam, then if
> desired I could use exiftool to write selected jpeg metadata back to the
> corresponding raw file. And the jpeg offers visual confirmation that the
> jpeg actually belongs to its corresponding raw file.
>
> I've separated all my in-camera-produced jpegs into a separate album from my
> raw files. I don't shoot simultaneous raw and jpeg (slow, uses a lot of
> extra space on the card), so there is no problem of confusing an extracted
> jpeg from a simultaneously-produced jpeg.
>
> dcraw can extract the embedded jped: "dcraw -e *.cr2" (my camera is Canon
> 400d/xti). Not all the metadata gets carried across from raw to jpeg, but
> enough does, I think, for my purposes. 
>
> exiv2 also can extract an embedded jpeg and keeps some? all? the metadata,
> but I don't know how to use exiv2 - does anyone have any hints?
>
> Thanks for advice,
> Elle Stone
>