(no subject)

[Nicola Botta]

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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[hidden email]
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[Gilles Caulier-4]

You must to try with last digiKam 2.5.0 and kipi-plugins 2.5.0. DNG
converter is a kipi plugin.

Gilles Caulier

2012/5/2 Nicola Botta <[hidden email]>:

> 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
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

_______________________________________________
Digikam-users mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-users

[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 <[hidden email]> 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
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

_______________________________________________
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[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-users

[Anders Stedtlund]

Hi Nicola,

This is not a solution of any kind but a note on the preview issue.

I remember that I had problems with showing the same image, "Embedded
preview loads full-sized images"  unchecked or not. That is, always
the full image was shown. This was with my Canon CR2 raw files. I know
that someone else had the same problem, but don't know who.

I'm at the moment on digiKam/kipi-plugins 2.5.0, but I haven't checked
to see if that problem has been sorted out for me. Can't test right
now either.

It might be the same problem for you anyway, the DNG is not showing
the embeded preview.

/Anders

2012/5/3 Nicola Botta <[hidden email]>:

> 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 <[hidden email]> 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
>> _______________________________________________
>> Digikam-users mailing list
>> [hidden email]
>> https://mail.kde.org/mailman/listinfo/digikam-users
>
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

_______________________________________________
Digikam-users mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-users

[botta]

Anders Stedtlund <[hidden email]> wrote:

> It might be the same problem for you anyway, the DNG is not showing
> the embeded preview.

This is possible but it does not explain why DNG decoding works
fine (Edit) while DNG previewing sucks.

My understanding at this point is that DNG previewing is based on some
hard-wired decoding algorithm which is not controllable by user-defined
settings.

There have been suggestions for redesigning the "Thumbnail click action"
and the "Embedded preview loads full-sized images" settings because of
similar issues, see for instance:

http://digikam.1695700.n4.nabble.com/Bug-205776-New-quot-Embedded-preview-loads-full-image-size-quot-does-not-only-do-what-it-says-confuss-td1718583i40.html

In fact, the main problem with digikam since I have used it has always
been that it is difficult for users to get consistent results, in
particular for RAW files previewing and decoding.

My impression is that the algorithms are fine but the UI needs some
cleanup / redesign.

Best,
Nicola

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[hidden email]
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[botta]

Gilles,

I have meanwhile tested 1.2.0 (Debian stable), 1.9.0 (Debian testing)
and 2.5.0 (Windows in Virtualbox).

The behavior is exactly the same: previews (half sized or via embedded
JPGs) look as if auto-brightness was always active. Unfortunately there
seems to be no way for users to setup how images are displayed in
previews.

In practice, previews are often significantly brighter/darker than the
images that one obtains by opening the image editor (with auto
brightness switched off) and significantly brighter/darker than the
images shown in thumbnails.

For completeness, I have also tried Lightroom 4 (again, under Windows in
Virtualbox). In LR4, previews of DNG files are consistent with views of
the correspondent JPG files and with the thumbnail views.

Although I find the UI of Digikam nicer that that of LR4 (which I do not
have really learned, so far) I think that the problem I have reported is
serious and prevents many users to make Digikam their first choice.

In fact, because the preview of DNG files sucks, users are de facto
forced to save both DNGs and JPGs on SD or, alternatively, to save only
DNGs and open the image editor every time they need to inspect a
picture.

best,
Nicola




Gilles Caulier <[hidden email]> wrote:

> You must to try with last digiKam 2.5.0 and kipi-plugins 2.5.0. DNG
> converter is a kipi plugin.
>
> Gilles Caulier
>
> 2012/5/2 Nicola Botta <[hidden email]>:
> > 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
> > _______________________________________________
> > Digikam-users mailing list
> > [hidden email]
> > https://mail.kde.org/mailman/listinfo/digikam-users

_______________________________________________
Digikam-users mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-users

[botta]

Here a screenshot (digikam 1.2.0) to exemplify the problem:

The thumbnail views of the DNG and of the JPG files are quite similar
but the embedded JPG preview (of the DNG file, on the left of the light
table) is remarkably different from the reduced size preview (of the JPG
file, on the right).



My understanding is that previews of DNG files (via the in-DNG embedded
JPG file or via RAW decoding always apply brightness auto-correction no
matter what the settings are.

If this is the case, I would argue it is an error. As I pointed out in
my original post, this behavior makes previews of DNG files virtually
unusable and forces users to save both DNG and JPG files to card.

If I am missing something, please let me know. Any help is highly
appreciated.

Best,
Nicola



Nicola Botta <[hidden email]> 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
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

_______________________________________________
Digikam-users mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-users