[Digikam-users] (no subject) Bad embedded preview

[Nicola Botta]

I apologize for the missing "subject" in my previous post. One more
piece of information on the reported problem:

The problem is *not* related to RAW decoding or DNG conversion
whatsoever. As reported, RAW decoding works fine. I have not tried DNG
conversion. Both the DNG and the JPG files I'm considering are straight
from the camera. When I take pictures, I save both (built-in-camera)
DNGs and JPGs files to the SD card.

What is puzzling is that DNG thumbnail views looks fine but DNG previews
(after double-click on the thumbnail) are terrible.

My understanding is that thumbnail views and DNG previews (with
"Embedded preview loads full-sized images" unchecked) should be
renderings of the same JPG file (in-camera generated, embedded in the
DNG file) and should look similar.

Instead, previews seem to apply some sort of brightness auto-correction
and such behavior does not seem to be avoidable with the configuration
options available to users.

This is very frustrating and, in fact, the only reason why I am looking
for a digikam alternative.

Best,
Nicola


Nicola Botta <nicola at pik-potsdam.de> wrote:

> With 
> 
> Qt: 4.6.3
> KDE Development Platform: 4.4.5 (KDE 4.4.5)
> digiKam: 1.2.0
> 
> and, more recently
> 
> Qt: 4.7.4
> KDE Development Platform: 4.7.4 (4.7.4)
> digiKam: 1.9.0
> 
> I have consistently experienced the same problem when working with DNGs
> and JPGs generated by Ricoh GXR modules:
> 
> For a given picture, the thumbnail views of both the DNG and of the JPG
> files are fine. Import (RAW decoding) of the DNG file is fine too with
> Auto-Brightness unchecked. The JPG preview is also fine but the DNG
> preview often looks horrible.
> 
> No matter whether "Embedded preview loads full-sized images" is checked
> or unchecked, DNG previews often look quite different from their JPG
> counterparts *AND* from from their raw decoding imports. 
> 
> In many cases, DNG previews look like raw decodings with Auto-Brightness
> checked. It is as if brightness always was auto-adjusted in DNG
> previewing.
> 
> This is quite frustrating since it makes DNGs unusable for previewing
> and forces me to save both DNGs and JPGs versions of the same picture.
> 
> Any idea how to solve this problem ? Any help is highly
> appreciated. Best, Nicola
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