https://bugs.kde.org/show_bug.cgi?id=398838
Bug ID: 398838
Summary: Standard color profile for Grayscale images has a
gamma 2.2 tone reproduction curve
Product: krita
Version: 4.1.1
Platform: MS Windows
OS: All
Status: REPORTED
Severity: normal
Priority: NOR
Component: Color models
Assignee: krita-bugs-n...@kde.org
Reporter: ch-ba...@outlook.com
Target Milestone: ---
Standard color profile for Grayscale images obviously has gamma 2.2 instead of
a sRGB TRC.
Reproducible: always
Steps to reproduce:
1. open any image in Krita, e.g a 16 bit per channel integer precision
grayscale TIFF, or an RGB 8 bit per channel integer precision JPEG).
2. Click "Image -> Properties... -> Image color space -> Color Space Browser".
3. In the Color Space Browser, select Model: "Grayscale/Alpha". Select bit
depth: "8 bit". Then select Profile: "gray built-in (standard)"
Observed behaviour:
The diagram at the right side of the Color Space Browser shows a tone
reproduction curve which looks more like gamma = 2.2 (equals the TRC of the
profile "Gray-D50-elle-V2-g22.icc") instead of the expected(?) sRGB TRC (for 8
bit). Additionally, regardless of the bit depth chosen in step 3, the color
profile "Gray built-in" is always tagged as "(standard)" in the profile list
for the model "Grayscale/Alpha".
Expected behaviour:
In the diagram at the right side of the the Color Space Browser, a sRGB tone
reproduction curve should be seen which should look like the TRC of the profile
"Gray-D50-elle-V2-srgbtrc".
I can imagine that the assignment of the tag "(standard)" to color profiles for
grayscale images is intended to be consistent with the choice for RGB images.
If that is true, the profile "Gray built-in" should not be tagged "(standard)".
Instead you might want to assign the default profile following the rules in the
table below:
Model depth Standard Color profile name TRC
Grayscale/Alpha 8 bit Gray-D50-elle-V2-srgbtrc.icc (standard) sRGB TRC
Grayscale/Alpha >=16 bit Gray-D50-elle-V2-g10.icc (standard) gamma=1.0
Additional Information :
My System configuration:
Krita
Version: 4.1.1
OS Information
Build ABI: x86_64-little_endian-llp64
Build CPU: x86_64
CPU: x86_64
Kernel Type: winnt
Kernel Version: 10.0.17134
Pretty Productname: Windows 10 (10.0)
Product Type: windows
Product Version: 10
OpenGL Info
**OpenGL not initialized**
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