[Digikam-users] Incorrect thumbnails for *.CR2 Canon RAW files in the transfer window

[Gilles Caulier]

Guillaume is right here. PTP or other protocols are driven by
libgphoto2 drivers. Results in thumbnails view depand of level of
thumbs extraction support implemented.

Note than Canon do not implement USB mass storage connection to
computer, like others camera maker (it's shame).

I recommend, if you can, to use a compact flash card reader. in this
case digiKam  use a customized driver is digiKam core which is abe to
show RAW files preview in all cases (thrue libkdcraw interface).

Best

Gilles Caulier

2008/7/14 Guillaume Castagnino <casta at xwing.info>:
> Le lundi 14 juillet 2008, spade2008 a écrit :
>> Hi,
>>
>> Everything describing the problem is in the subject, but I can add
>> that: - digikam version is 0.9.3
>> - the camera is Canon 350D
>> - *.CR2 files are displayed, not as correct thumbnails, but as
>> generic ones. I still can transfer them
>> - *.JPG files are correctly displayed as thumbnails in the transfer
>> window - *.CR2 files are correctly displayed as thumbnails in the
>> albums window, once the transfer is done
>> - I tried to add "*.CR2" in the list of "RAW files" in "MIME types",
>> because I thought that "*.cr2" that was already there was not enough,
>> but the behaviour is not better.
>
> Hi,
>
> I have the same with my EOS 5D, but it's OK with my EOS 400D since the
> 1.1.0 firmware. Before this version, this was the same, thumbnails were
> not displayed.
>
> The change in the 400D firmware that make the thumbnails display is :
>> Changes in Version 1.1.0:
>>   1. Adds support for the new Media Transfer Protocol (MTP) USB
>> protocol.
>>    Adds support for the Media Transfer Protocol (MTP), which has
>> greater expandability than the Picture Transfer Protocol (PTP) used
>> for communication between the camera and the computer up to now.
>
>
> IMHO, there is absolutly no problem here : the PTP protocol used in
> older Canon Camera does not allow to see thumbnails of raw files before
> file transfer => that means, PTP does not allow to extract thumb from
> metadata (that is where the thumbnail come from for RAW files : the
> metadata)
>
> Such functionnality is enabled by MTP support (or at least extended PTP
> support), which the 350D or 5D have not.
>
> Beware that this part of the transfer is managed by libgphoto, not
> digikam directly. You should have the same "problem" with all programs
> that use libgphoto for PTP transfers. But IMHO no bug here, only a
> protocol limit.
>
> Regards,
> Guillaume
>
> --
> Guillaume Castagnino
>    guilc at laposte.net / casta at xwing.info
> GnuPG/PGP key :
> http://wwwkeys.pgp.net:11371/pks/lookup?op=vindex&search=0x8AF468AF
> Fingerprint : CD52 FE40 9592 BA1E E89D 5FB6 820E 4742 8AF4 68AF
> _______________________________________________
> Digikam-users mailing list
> Digikam-users at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-users
>