[Digikam-users] RAW file preview using embedded JPEG ?

[Vincent Tassy]

Ok, here's something interesting ...

I have CR2 files produced by the 3 Canon cameras I own: 400D, 60D, S100

on my Home computer (Digikam 4.3) only the preview of the CR2 produced by the 60D show the embedded JPEG preview - previewing the CR2 from 400D and S100 show 
Half size Raw preview.

On my work laptop (Digikam 3.5) all the CR2 files are previewed based on the embedded JPG ...

Odd isn't it ?

What I see by using exiftool -PreviewImage is that the embedded JPG of my 60D CR2 are 17Mpx whereas the embedded JPGs in the 400D is 2.5Mpx and the S100 2Mpx

Given that my home computer has a much larger screen resolution than my work laptop, could the behaviour I'm seeing be due to that difference in the available 
Mpx of the preview JPGs ? Does digikam override the setting if it thinks there's not enough pixels for the preview image ?

Just guessing :/

Vince.


On 10/13/2014 06:50 PM, Vincent Tassy wrote:
> Hi Gilles,
>
> I was very happy with your answer. I tried it on my work computer where I have an old digikam 3.5 and it worked like a charm.
>
> Now back at home, where I run Digikam 4.3 on a Fedora 20, there is a problem :/
> Check out the following screenshots. The checkbox in the settings is un-ticked but the Raw preview still shows "Half size raw preview" ! (I've tried
> closing/relaunching digikam)
>
> https://drive.google.com/file/d/0B1A_V-o8tk0qdWRlSUVLR1NHaE0/view?usp=sharing
> https://drive.google.com/file/d/0B1A_V-o8tk0qOVpqVkNvdVZLMjA/view?usp=sharing
>
> What's even more strange is that when I browse my image collection, some CR2 files preview with the Embedded JPEG, some keep showing the Half Size RAW preview !
> I don't understand the logic ...
>
> Is there maybe a cache of those preview images ?
> Any other idea ?
>
> Thanks,
>
> Vince.
>
> On 10/13/2014 11:26 AM, Gilles Caulier wrote:
>> digiKAm will show Raw JPEG preview if you switch right PReview Option
>> in digiKam/Setup/Album section...
>>
>> Gilles Caulier