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Arnd Baecker

raw problems

Hi,

I was about to test the patch
http://bugs.kde.org/show_bug.cgi?id=142055
but before I wanted to look at that current status
to see the difference.

There are various problems in the following situation:
Take the same image in the two versions RAW and JPG
(as they come out of the camera, Canon EOS 350D for this example),
with no color management enabled.

Tests A:
"RAW Files Decoding Settings"
- 16 bits color depth
- interpolate RGB as four colors
+ White balance: "Use camera white balance"
+ Automatic color balance
+ Highlights: Solid white
+ Brightness: 1.0
+ Interpolation: Bilinear
- noise reduction
- enable chromatic aberrations

Tests A - results for the comparison of RAW vs. JPG
---------------------------------------------------

- the thumbnails look very similar
(the histogram of a screenshot for each thumb
show only a small variation)

- The histogramms for RAW and JPG differ considerably
(for the raw one all its weight is near small values).

- BUG:
first going to the CR2 is fine, histogram is computed
(takes long!) and shown.
Then go to JPG - ok.
Then back to the CR2 - the "Histogram" TAB says
"Loading image" and this never finishes.
(will file a separate BKO for this)

- Then, in preview mode (Setting: extract embedded preview)
going back and forth between JPG and RAW
one sees that RAW and JPG differ in width slightly
(Colors etc. are essentially identical)
- With setting: "Embedded preview load full image size"
the colors are different
(the raw one appears much more green).

- Loading the images into the editor,
they look pretty much like
those from the preview (when "Embedded preview load full image size"
is activated), i.e. the raw one appears much more green.

Tests B - results
-----------------

change in the setting:
+ 16 bits color depth

Everything as in A), but:
In image editor: in 16 Bit: almost dark image
(which corresponds to the histogramm seen before ;-)

With patch
----------

Applying
http://casta.nerim.net/digiKam/digikam-kde3-WB-ufraw-multiplier.patch
(which did not change anything?)
and
wget http://casta.nerim.net/digiKam/libkdcraw-kde3-dcraw-WB.patch
wget http://casta.nerim.net/digiKam/digikam-kde3-dcraw-WB.patch
wget http://casta.nerim.net/digiKam/kipi-plugins-kde3-dcraw-WB.patch

Hmm, I don't see a different behaviour compared to A).
So presumably I am looking for an effect at the wrong place
(Just showing off that I haven't understood how to work with
raw under digikam ...;-)

Best, Arnd
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Guillaume Castagnino-5

Re: raw problems

Hi,

For your 16bits test, patch will NOT solve the dark image issue :
To change this, you will have to use a good ICC profile.
For example here :
http://digikam3rdparty.free.fr/ICCPROFILES/CameraProfiles/BBP.4.9.5/

I see you have a Canon camera :
To use the right profile, I have this table for Canon (not complete
but...) :
Canon EOS 10D canona.icm
Canon EOS 20D canon9.icm
Canon EOS 300D canona.icm
Canon EOS 350D canon9.icm
Canon EOS 400D canone.icm

Applying the good icc profile will lead you to a well exposed image in
16bits mode ;)

Regards,
Guillaume

Le mardi 4 septembre 2007, Arnd Baecker a écrit :

> Hi,
>
> I was about to test the patch
> http://bugs.kde.org/show_bug.cgi?id=142055
> but before I wanted to look at that current status
> to see the difference.
>
> There are various problems in the following situation:
> Take the same image in the two versions RAW and JPG
> (as they come out of the camera, Canon EOS 350D for this example),
> with no color management enabled.
>
> Tests A:
> "RAW Files Decoding Settings"
> - 16 bits color depth
> - interpolate RGB as four colors
> + White balance: "Use camera white balance"
> + Automatic color balance
> + Highlights: Solid white
> + Brightness: 1.0
> + Interpolation: Bilinear
> - noise reduction
> - enable chromatic aberrations
>
>
> Tests A - results for the comparison of RAW vs. JPG
> ---------------------------------------------------
>
> - the thumbnails look very similar
> (the histogram of a screenshot for each thumb
> show only a small variation)
>
> - The histogramms for RAW and JPG differ considerably
> (for the raw one all its weight is near small values).
>
> - BUG:
> first going to the CR2 is fine, histogram is computed
> (takes long!) and shown.
> Then go to JPG - ok.
> Then back to the CR2 - the "Histogram" TAB says
> "Loading image" and this never finishes.
> (will file a separate BKO for this)
>
> - Then, in preview mode (Setting: extract embedded preview)
> going back and forth between JPG and RAW
> one sees that RAW and JPG differ in width slightly
> (Colors etc. are essentially identical)
> - With setting: "Embedded preview load full image size"
> the colors are different
> (the raw one appears much more green).
>
> - Loading the images into the editor,
> they look pretty much like
> those from the preview (when "Embedded preview load full image
> size" is activated), i.e. the raw one appears much more green.
>
>
> Tests B - results
> -----------------
>
> change in the setting:
> + 16 bits color depth
>
> Everything as in A), but:
> In image editor: in 16 Bit: almost dark image
> (which corresponds to the histogramm seen before ;-)
>
> With patch
> ----------
>
> Applying
> http://casta.nerim.net/digiKam/digikam-kde3-WB-ufraw-multiplier.patch
> (which did not change anything?)
> and
> wget http://casta.nerim.net/digiKam/libkdcraw-kde3-dcraw-WB.patch
> wget http://casta.nerim.net/digiKam/digikam-kde3-dcraw-WB.patch
> wget http://casta.nerim.net/digiKam/kipi-plugins-kde3-dcraw-WB.patch
>
> Hmm, I don't see a different behaviour compared to A).
> So presumably I am looking for an effect at the wrong place
> (Just showing off that I haven't understood how to work with
> raw under digikam ...;-)
>
> Best, Arnd
> _______________________________________________
> Digikam-devel mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-devel

--
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Bugzilla from casta@xwing.info

Re: raw problems

In reply to this post by Arnd Baecker

--
Guillaume Castagnino
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Arnd Baecker

Re: raw problems

In reply to this post by Guillaume Castagnino-5

Hi Guillaume,

On Tue, 4 Sep 2007, Guillaume Castagnino wrote:

> Hi,
>
> For your 16bits test, patch will NOT solve the dark image issue :
> To change this, you will have to use a good ICC profile.
> For example here :
> http://digikam3rdparty.free.fr/ICCPROFILES/CameraProfiles/BBP.4.9.5/
>
> I see you have a Canon camera :
> To use the right profile, I have this table for Canon (not complete
> but...) :
> Canon EOS 10D canona.icm
> Canon EOS 20D canon9.icm
> Canon EOS 300D canona.icm
> Canon EOS 350D canon9.icm
> Canon EOS 400D canone.icm
>
> Applying the good icc profile will lead you to a well exposed image in
> 16bits mode ;)

Not for me ;-):
- I turned on color-management
and defined the Color Profiles Directory
- editing the .CR2 brings up the Color Management dialogue
in which I use the "selected profile" (canon9.icm)
as input profile and workspace profile
- (for 8Bit the resulting image looks brighter than the JPG)
- for 16Bit: too dark again
Changing the workspace profile to "use default"
looks better (i.e. brighter), but still too dark (compared to the JPG)

And then it even complains about my the normal JPGs
("This picture has been assigned a color profile that does not match with
your default workspace color profile.
Do you want to convert it ..." - current workspace profile
is said to be AdobeRGB - not sure where I defined that.

Well, I think I am a hopeless case about
color-management&Co at this point - should read more about
this and I better shut up here!
((Does the wish to work with 16 Bit raw but not to be bothered
by color-management make any sense?))

Thanks a lot,

Arnd

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Gilles Caulier-4

Re: raw problems

In reply to this post by Arnd Baecker

2007/9/4, Arnd Baecker <[hidden email]>:

Hi,

I was about to test the patch
http://bugs.kde.org/show_bug.cgi?id=142055
but before I wanted to look at that current status
to see the difference.

There are various problems in the following situation:
Take the same image in the two versions RAW and JPG
(as they come out of the camera, Canon EOS 350D for this example),
with no color management enabled.

Tests A:
"RAW Files Decoding Settings"
- 16 bits color depth
- interpolate RGB as four colors
+ White balance: "Use camera white balance"
+ Automatic color balance
+ Highlights: Solid white
+ Brightness: 1.0
+ Interpolation: Bilinear
- noise reduction
- enable chromatic aberrations

Tests A - results for the comparison of RAW vs. JPG
---------------------------------------------------

- the thumbnails look very similar
  (the histogram of a screenshot for each thumb
   show only a small variation)

- The histogramms for RAW and JPG differ considerably
  (for the raw one all its weight is near small values).

Important point in general :

- RAW file are container :
=> RAW image data
=> metadata
=> JPEG preview image

This is want mean than RAW include a JPEG file ! This one is used to display RAW picture very quickly on tv screen using camera device. This picture is very similar than if you use your camera in RAW+JPEG mode, excepted than JPEG image embedded in RAW is generaly smalless than a real JPEG picture taken directly.

In digiKam we use this embeded JPEG image to render thumbnail and display preview of RAW files if no whole image is used for that (check setup)

About histogram, RAW and JPEG histogram differt. It's normal : this is not the same picture (in the same color space: JPEG = sRGB, RAW = linear).

- BUG:
  first going to the CR2 is fine, histogram is computed
  (takes long!) and shown.
  Then go to JPG - ok.
  Then back to the CR2 - the "Histogram" TAB says
  "Loading image" and this never finishes.
  (will file a separate BKO for this)

yes, sometimes, i can reproduce it. This come from libkdcraw and multithreading which use KProcess. Marcel, normally this bug must be fixed in KDE3 branch or it's another probem with re-entrance of KProcess ?

Note : libkdcraw for KDE4 do not have this problem. It's a pure QT4 implementation which use QProcess & co...

Gilles

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Arnd Baecker

Re: raw problems

On Tue, 4 Sep 2007, Gilles Caulier wrote:

[...]

> 2007/9/4, Arnd Baecker <[hidden email]>:

> > - The histogramms for RAW and JPG differ considerably
> > (for the raw one all its weight is near small values).
>
>
> Important point in general :
>
> - RAW file are container :
> => RAW image data
> => metadata
> => JPEG preview image
>
> This is want mean than RAW include a JPEG file ! This one is used to display
> RAW picture very quickly on tv screen using camera device. This picture is
> very similar than if you use your camera in RAW+JPEG mode, excepted than
> JPEG image embedded in RAW is generaly smalless than a real JPEG picture
> taken directly.
>
> In digiKam we use this embeded JPEG image to render thumbnail and display
> preview of RAW files if no whole image is used for that

Yes, and they look essentially the same

> (check setup)

Yes, with setting: "Embedded preview load full image size"
the colors are different
(the raw one appears much more green).

> About histogram, RAW and JPEG histogram differt. It's normal : this is not
> the same picture (in the same color space: JPEG = sRGB, RAW = linear).

I perfectly understand.
But from the users point it looks confusing:
two images which appear to be the same in the thumbnail view
have completely different histograms.
How do other programms deal with this?

I had another look at the handbook:
http://docs.kde.org/development/en/extragear-graphics/digikam/using-iccprofile.html
about using ICC profiles.
Looking at the second diagramm, I would think that
non-RAWs should never get into the color-management workflow?

Why do I then get for normal JPGs
> ("This picture has been assigned a color profile that does not match
> with your default workspace color profile.
> Do you want to convert it ..." - current workspace profile
> is said to be AdobeRGB - not sure where I defined that.

Anyway, nothing urgent at all from my side, just
would like to understand and use it at some point ... ;-)

Many thanks,

Arnd
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Marcel Wiesweg

Re: raw problems

In reply to this post by Gilles Caulier-4

> > - BUG:
> > first going to the CR2 is fine, histogram is computed
> > (takes long!) and shown.
> > Then go to JPG - ok.
> > Then back to the CR2 - the "Histogram" TAB says
> > "Loading image" and this never finishes.
> > (will file a separate BKO for this)
>
> yes, sometimes, i can reproduce it. This come from libkdcraw and
> multithreading which use KProcess. Marcel, normally this bug must be fixed
> in KDE3 branch or it's another probem with re-entrance of KProcess ?
>
> Note : libkdcraw for KDE4 do not have this problem. It's a pure QT4
> implementation which use QProcess & co...

I have found this once in the KDE4 version, but then I could not reproduce.
There must be a problem somewhere, now that you all also see it.
It's always so difficult with non-reproducable errors :-(
But I will see what I can do.

>
> Gilles

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