Bug 453417

Summary:	Color Management not working properly
Product:	[Applications] digikam	Reporter:	harald.aust
Component:	ColorManagement-Core	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	caulier.gilles, metzpinguin
Priority:	NOR
Version First Reported In:	7.6.0
Target Milestone:	---
Platform:	Snap
OS:	Linux
Latest Commit:	https://invent.kde.org/graphics/digikam/commit/095033ac24677ad9ddcec2e12c625283bf17153a	Version Fixed/Implemented In:	7.7.0
Sentry Crash Report:

Description harald.aust 2022-05-05 12:28:56 UTC

SUMMARY
I just tried my hands on digiKam under Linux Mint Mate 20.2, running in a Virtual Box under Windows 10 host, and can't get Color Management to work properly (whereas, with digiKam under Windows, it works as it is supposed to).

I'm not a Linux expert, so it is possible that the problem is not on digiKam's side but on my own. However, color management works correctly in other applications like Gimp, XnView, or Xviewer.

OBSERVATIONS
- In  Configure digiKam/Color Management/Profiles , I don't have any other option than "Monitor Profile from System Settings". There *are* .icm profiles under at least one of the default locations, as well as in the directory I can enter under "Color Profiles Repository", but they don't create a list where I can choose the profile from.
- No matter whether I check "Use color managed view for previews and thumbnails" or not, the behavior is always as follows:
   - Thumbnails: no monitor profile is applied; photos are over-saturated on my wide-gamut monitor.
   - Previews and Slideshow: the correct monitor profile (supposedly the "Profile from System Settings") is applied; photos are displayed correctly (i.e. like in other applications, or in digiKam under Windows).


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma:  Linux Mint Mate 20.2
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 Maik Qualmann 2022-05-05 13:28:40 UTC

The problem with Mint or Ubuntu is that they are not native digiKam packages. But so-called snap packages. Snap uses a sandox, so no access to files outside the snab rights area. These digiKam packages are unusable and broken by design. Use our AppImage, it only needs to be made executable and can be started directly.

Maik

Comment 2 harald.aust 2022-05-06 13:04:27 UTC

As a matter of fact, I observed the behavior I described when using "digiKam-7.6.0-x86-64.appimage", downloaded from your web site.

Comment 3 Maik Qualmann 2022-05-06 15:05:37 UTC

(In reply to harald.aust from comment #0)
> - In  Configure digiKam/Color Management/Profiles , I don't have any other
> option than "Monitor Profile from System Settings".

I have not read this before. There is already a system color management running in their Linux distribution, so digiKam cannot change it. See this bug 347114

Disable system-wide color management. There are currently various color management systems under Linux, none of which have really become the "standard" yet. It is not possible to support everyone.

Maik

Comment 4 harald.aust 2022-05-18 09:20:57 UTC

Maik,

seems indeed the same as #347114. Your sentence there, "The "Monitor Profile" combobox is only grayed out when digikam detects an installed system color profile." explains why I can't select a profile. Different behavior from Windows, though, where I *have to* select a profile manually despite a system-wide one being installed.

Disabling system-wide color management is not an option since other programs rely on it. Actually, digiKam using the system-wide profile is fine for me (just different from Windows, but if that is intended, ok). But the question remains why the profile is not applied to the thumbnails?

Best regards,
Harald

Comment 5 Maik Qualmann 2022-05-18 11:49:43 UTC

For the thumbnails I can reproduce so far that after setting a monitor profile digiKam has to be restarted so that the thumbnails take over it. The settings are probably not transferred to the thumbnail engine at runtime, I'll take a look at that.

Maik

Comment 6 Maik Qualmann 2022-05-18 18:40:48 UTC

Git commit 095033ac24677ad9ddcec2e12c625283bf17153a by Maik Qualmann.
Committed on 18/05/2022 at 18:39.
Pushed by mqualmann into branch 'qt5-maintenance'.

applying color profile changes to the thumbnail loading thread
FIXED-IN: 7.7.0

M  +2    -1    NEWS
M  +2    -0    core/app/main/digikamapp.cpp

https://invent.kde.org/graphics/digikam/commit/095033ac24677ad9ddcec2e12c625283bf17153a