[Bug 172196] New: Color managed view is inaccurate

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196

           Summary: Color managed view is inaccurate
           Product: digikam
           Version: 0.9.4
          Platform: Gentoo Packages
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: NOR
         Component: Color Management
        AssignedTo: [hidden email]
        ReportedBy: [hidden email]


Version:           0.9.4 (using KDE 3.5.9)
OS:                Linux
Installed from:    Gentoo Packages

When I use DigiKam to prepare images for printing, I always compare the final
result using both DigiKam, CinePaint and the GIMP. All applications are
configured to use the same color management profiles, rendering intent and
blackpoint compensation.

Often, it strikes me how different images look in DigiKam compared to the GIMP
and CinePaint. The same image viewed using the GIMP and CinePaint look
identical, while it looks quite different in DigiKam.

When I print my images using a color managed printing lab, both GIMP and
CinePaint are spot on. The print matches the display of both applications. So I
guess that something is wrong with the color managed view of DigiKam.

I will attach some screenshots of photographs shown in all three applications.
The screenshots show that the view of DigiKam is quite a bit brighter, and the
colors are much warmer.


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #1 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:41:23 ---
Created an attachment (id=27694)
 --> (http://bugs.kde.org/attachment.cgi?id=27694)
photo 1 in digikam


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #2 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:42:01 ---
Created an attachment (id=27695)
 --> (http://bugs.kde.org/attachment.cgi?id=27695)
photo 1 in cinepaint


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #3 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:42:33 ---
Created an attachment (id=27696)
 --> (http://bugs.kde.org/attachment.cgi?id=27696)
photo 1 in GIMP


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #4 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:43:06 ---
Created an attachment (id=27697)
 --> (http://bugs.kde.org/attachment.cgi?id=27697)
photo 2 in digikam


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #5 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:43:43 ---
Created an attachment (id=27698)
 --> (http://bugs.kde.org/attachment.cgi?id=27698)
photo 2 in cinepaint


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #6 from Dik Takken <d h j takken xs4all nl>  2008-10-05 13:44:15 ---
Created an attachment (id=27699)
 --> (http://bugs.kde.org/attachment.cgi?id=27699)
photo 2 in GIMP


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #7 from Andi Clemens <andi clemens gmx net>  2008-10-05 13:56:15 ---
Despite the fact that I don't see a difference in the provided images (maybe my
laptop screen isn't that good), I also think color management is sometimes not
working correctly.

Often I correct a photo in digiKam and save the results in a new (jpg) image.
If I open this image in another software, the colors look always wrong. For
example GIMP says that there is an embedded profile and that I can import it.
If I do so, colors are wrong. The colors are also wrong if I don't import the
profile, so it really doesn't matter what action I'm choosing, images that have
been corrected in digiKam are not opened correctly in other software.

Same discussion happened here #165650 a while ago...


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

http://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #8 from Andi Clemens <andi clemens gmx net>  2008-10-05 13:56:51 ---
Hmm shortcut isn't working...
http://bugs.kde.org/show_bug.cgi?id=165650


--
Configure bugmail: http://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Marcel Wiesweg]

https://bugs.kde.org/show_bug.cgi?id=172196


Marcel Wiesweg <[hidden email]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[hidden email]




--- Comment #9 from Marcel Wiesweg <marcel wiesweg gmx de>  2009-08-20 23:17:17 ---
Can you provide me with a testcase, or test current trunk / 1.0-beta4?
On my laptop monitor, the colors in the given example images all look the same
to me. And I can't test because they are screenshots.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Dik Takken-2]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #10 from Dik Takken <d h j takken xs4all nl>  2009-08-23 22:24:10 ---
You don't really need an accurate monitor. You can also compare the histograms
of the screenshots (only the image areas of course) and you'll see what I mean.
On an accurate monitor, the differences you see in the histograms translate
into a different looking image. The difference is subtle, but definitely
noticeable. So, anyone can test by creating screenshots of their own display
and compare histograms. That's much easier and more accurate than looking at
the images themselves.

Unfortunately I can't test latest digikam at this moment.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Milan Knizek]

https://bugs.kde.org/show_bug.cgi?id=172196


Milan Knizek <[hidden email]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[hidden email]




--- Comment #11 from Milan Knizek <knizek volny cz>  2009-08-24 22:19:43 ---
Yes, the difference between digiKam and the other two is quite slight, but
existing (it also helps to look at them as at a slide-show rather then one next
to another).

Later this week, I will try myself with the current trunk and report the
findings.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Marcel Wiesweg]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #12 from Marcel Wiesweg <marcel wiesweg gmx de>  2009-08-25 18:08:14 ---
That would be great.
The color management code has in some parts been rewritten, so old bugs may
have been fixed (and new one created...).
My problem with this report is that it does not give me a hint at what is wrong
(in other reports, digikam did broad things like not using an embedded profile)
so if you notice any problem at least provide me with the original image and a
hint at the used profiles.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Milan Knizek]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #13 from Milan Knizek <knizek volny cz>  2009-08-26 20:26:23 ---
Created an attachment (id=36472)
 --> (http://bugs.kde.org/attachment.cgi?id=36472)
Comparison of AdobeRGB image displayed to sRGB display with various apps

It seems that digiKam 1.0.0 beta4 svn as of yesterday does not suffer the
described bug anymore (see the attached screenshot and compare with colour
checker tool in GIMP. The settings were: AdobeRGB embedded, sRGB working space,
sRGB display and "keep the embedded profile").

When I tested with ver. 1.0.0 beta3, digiKam failed to recognise the embedded
AdobeRGB and displayed it incorrectly.

Dik did not mention what was his setup (embedded profile, display profile,
working space profile) and did not provide the original image, so we can just
guess if the colour tint was just a result of wrong recognition of the embedded
profile or something else.

Unless anyone else reports problems, I would suggest to close the bug.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Gilles Caulier-4]

https://bugs.kde.org/show_bug.cgi?id=172196


Gilles Caulier <[hidden email]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |[hidden email]
         Resolution|                            |FIXED




--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

["Jens Müller"]

https://bugs.kde.org/show_bug.cgi?id=172196


Jens Mueller <[hidden email]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[hidden email]




--- Comment #14 from Jens Mueller <tschenser gmx de>  2009-12-24 14:14:46 ---
I think this bug entry is still valid. I found a example image at
http://www.locus-caementitium.de/download/lcf_galerie.jpg  Digikam show other
colors than krita (krita is more natural, look for the red seat in front and
the wall in the background). The colors of krita also match the colors of
windows photo viewer. Applications also wrong: gwenview, XnView. So please
reopen this entry.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

["Jens Müller"]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #15 from Jens Mueller <tschenser gmx de>  2009-12-24 14:20:00 ---
Created an attachment (id=39312)
 --> (http://bugs.kde.org/attachment.cgi?id=39312)
comparison of digikam and krita

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Marcel Wiesweg]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #16 from Marcel Wiesweg <marcel wiesweg gmx de>  2009-12-24 15:33:27 ---
Which color profile is embedded in the photo and how can I access it?

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

[Milan Knizek]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #17 from Milan Knizek <knizek volny cz>  2009-12-24 21:33:00 ---
There is no ICC profile embedded. It seems to use some Adobe's markers.
Exif.Colorspace is unknown (i.e. not sRGB) and exiftool -v reports:

JPEG APP14 (12 bytes):
  + [BinaryData directory, 7 bytes]
  | DCTEncodeVersion = 100
  | APP14Flags0 = 16384
  | APP14Flags1 = 0
  | ColorTransform = 2

Some googling results in:
JPEG Adobe Tags

The "Adobe" APP14 segment stores image encoding information for DCT filters.

    Index    Tag Name     Writable    Values / Notes
    0     DCTEncodeVersion     N      
    1     APP14Flags0     N     Bit 15 = Encoded with Blend=1 downsampling
    2     APP14Flags1     N      
    3     ColorTransform     N     0 = Unknown (RGB or CMYK)
                                1 = YCbCr
                                2 = YCCK

I do not know what it means from the viewpoint of colour management. Both
CinePaint and GIMP display the image the same (probably like Krita).

GIMP assigns sRGB and CinePaints assigns uncoated FOGRA CMYK profile (by
argyllcms) to the decoded image.

Non-colour managed ImageMagick's display command shows the channels swapped
(like CMYK).

Eye Of Gnome and DigiKam show the channels right, but oversaturated as in the
attachment by Jens.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel

["Jens Müller"]

https://bugs.kde.org/show_bug.cgi?id=172196





--- Comment #18 from Jens Mueller <tschenser gmx de>  2009-12-25 00:57:44 ---
Sorry, i dont know what color profile is embedded in this image. It is not a
image of mine, i found it in another bug entry, #105006. But I think the hint
is here that the image is encoded in cmyk colorspace compared to "normal" srgb
digitalcamera images.

--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Digikam-devel mailing list
[hidden email]
https://mail.kde.org/mailman/listinfo/digikam-devel