[dolphin] [Bug 500628] New: [Feature Request] Issues with Smooth scaling in the thumbnail and pixel art

[bugzilla_noreply at kde.org]

https://bugs.kde.org/show_bug.cgi?id=500628

            Bug ID: 500628
           Summary: [Feature Request] Issues with Smooth scaling in the
                    thumbnail and pixel art
    Classification: Applications
           Product: dolphin
           Version: unspecified
          Platform: Compiled Sources
                OS: Linux
            Status: REPORTED
          Severity: normal
          Priority: NOR
         Component: general
          Assignee: dolphin-bugs-null at kde.org
          Reporter: ender_non at outlook.com
                CC: kfm-devel at kde.org
  Target Milestone: ---

Created attachment 178775
  --> https://bugs.kde.org/attachment.cgi?id=178775&action=edit
Showing the pixel art look strange with smooth scaling thumbnail

SUMMARY
This is not really a bug, more so a feature request for the thumbnailer. I'm
posting this here because "meven" told me to. 
https://discuss.kde.org/t/dont-do-interpolation-in-thumbnails-when-the-image-is-small-resolution/30589 

In summary, 
- The thumbnailer uses Smooth Scaling. 
- This does not look good on pixel art.

STEPS TO REPRODUCE
1. Get some pixel art
2. View the thumbnail
3. Note the weird blurry look due to smooth scaling

OBSERVED RESULT
Blurry thumbnail for pixel art

EXPECTED RESULT
Sharp thumbnail for pixel art (not smoothed out)

SOFTWARE/OS VERSIONS

(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Arch Linux
KDE Plasma Version: 6.3.1
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2

ADDITIONAL INFORMATION

According to this reddit commenter here:
https://old.reddit.com/r/kde/comments/1ivwa2d/cant_disable_interpolation_on_the_dolphin/me9s4ja/ 

the thumbnail scaling method can be toggled via a single chosen enum. This is
in dolphin/src/kitemviews/private/kpixmapmodifier.cpp line 284, changing the
last argument in pixmap.scaled from Qt::SmoothTransformation to
Qt::FastTransformation.

Although I am not a C++ developer I propose two possible solutions. 

1: An option is added in the settings to toggle smooth scaling or fast scaling
for all thumbnail generation.

2: In the void function in the source code, check if the image resolution is
larger than some height and width constant. If it is, use smooth scaling,
otherwise if it is smaller then use fast scaling.

3: Do solution 2, but give the user an option to choose the height and width
boundary for Smooth vs Fast scaling in thumbnail.

-- 
You are receiving this mail because:
You are on the CC list for the bug.