Scaling Causing Extreme Blur/Haze on Mint XFCE: A Comprehensive Troubleshooting Guide

Understanding the Scaling Issue in Linux Mint XFCE

The problem of blurriness and haze after applying custom scaling in Linux Mint XFCE is a frustrating one. While scaling is essential for usability on high-resolution displays or for users with visual impairments, the resulting loss of clarity can negate its benefits. This guide aims to provide a thorough exploration of the potential causes and solutions, moving beyond surface-level adjustments to delve into the underlying graphics configurations and system settings. We will analyze the differences between Linux Mint and Zorin OS, and present in-depth fixes to ensure a crisp, scaled desktop environment.

Identifying the Root Cause: A Multi-Faceted Approach

Before diving into solutions, it’s crucial to understand what might be causing the blur. The issue isn’t always straightforward, often stemming from a combination of factors:

XFCE’s Built-in Scaling Limitations

XFCE, while lightweight and customizable, has historically had limitations in its handling of fractional scaling. Fractional scaling, scaling values that are not whole numbers (like 0.7 as mentioned in the initial problem), can introduce artifacts and blurriness because the system must render at a different resolution and then scale the result to fit the screen.

GTK Theme and Rendering Issues

The GTK theme used in Mint XFCE can impact rendering quality. Some themes are better optimized for scaled environments than others. Issues in the GTK rendering engine itself could also play a role.

X Server vs. Wayland

XFCE traditionally relies on the X Server (X11) display protocol. While X11 is mature, it was not originally designed for modern HiDPI displays and scaling. Wayland, a newer display protocol, handles scaling more efficiently, but XFCE’s Wayland support is not yet fully mature as of this writing.

Graphics Driver Incompatibility

Outdated or incompatible graphics drivers are frequently a source of display issues. The specific drivers used by Mint XFCE may differ from those used by Zorin OS, leading to differing scaling behavior.

Monitor and Laptop Hardware

While less likely, differences in the laptop’s display panel or its interaction with the graphics card could influence the perceived blurriness after scaling. Monitor EDID (Extended Display Identification Data) can sometimes cause scaling issues.

Troubleshooting Steps: A Comprehensive Toolkit

We will walk through a number of solutions step-by-step that users can use to diagnose and potentially fix their scaling problems.

Verify Graphics Drivers

  1. Identify your graphics card: Open a terminal and run lspci | grep VGA. This will identify your graphics card manufacturer and model.
  2. Check the currently installed driver: Use the ubuntu-drivers devices command to list recommended drivers.
  3. Install recommended drivers: Use the sudo ubuntu-drivers autoinstall command to install the recommended drivers, or use the Driver Manager GUI.
  4. Try proprietary drivers: If you are using open-source drivers (e.g., Nouveau for NVIDIA), experiment with proprietary drivers from NVIDIA or AMD. These drivers often provide better performance and scaling support. You can install proprietary drivers through the Driver Manager.
  5. Reboot: Reboot your system after installing or changing drivers.

Experiment with Different GTK Themes

  1. Open the Appearance settings: Navigate to “Settings” -> “Appearance”.
  2. Test different themes: Switch between different GTK themes. Some themes render fonts and UI elements more clearly at scaled resolutions than others. Try themes like “Adwaita” or “Greybird” as a baseline.
  3. Consider a custom theme: If no standard theme resolves the issue, explore custom themes designed for HiDPI displays. These themes often have optimized assets and font settings.

Adjust Font Settings

  1. Open the Font settings: Navigate to “Settings” -> “Appearance” -> “Fonts”.
  2. Enable Font Hinting: Ensure that font hinting is enabled. Experiment with different hinting styles (Slight, Medium, Full).
  3. Adjust DPI: Try increasing or decreasing the DPI (Dots Per Inch) setting. Higher DPI values make fonts larger, but may also exacerbate blurriness if not handled correctly by the system.
  4. Change Antialiasing: Experiment with different antialiasing settings. Grayscale antialiasing is generally preferred for LCD screens.
  5. Font Rendering: Make sure that the font rendering is configured correctly. Sometimes changing these setting values can fix the blurry font issue.

Modify XFCE Configuration Files

  1. Open the XFCE configuration file: Open a terminal and run xfconf-query -c xsettings -p /Gdk/DpiScale to check the current DPI scaling factor. The result should be 1.0 when scaling is off.

  2. Use xrandr for Scaling

  • First, identify the name of your display output using xrandr | grep " connected". It might be something like HDMI-0 or VGA-1.
  • Then, use xrandr to set a custom scaling factor. For example, to scale the display named HDMI-0 to 0.7 of its original size, you would first set a scaled resolution and then scale the output:
```bash
xrandr --output HDMI-0 --mode 1920x1080 --scale 0.7x0.7
```
  • You might need to adjust the 1920x1080 to a resolution that works well with your scaling factor and display. Experiment to find the best combination.
  • To revert to the original settings, you can use:
```bash
xrandr --output HDMI-0 --scale 1x1
```

  1. Edit .Xresources or .Xprofile: Some users have reported success by manually setting DPI scaling in their .Xresources or .Xprofile files. Create the file if it doesn’t exist.

    • Add the following lines to .Xresources (create the file if it doesn’t exist in your home directory):

      Xft.dpi: 96 # Or a different DPI value
Xft.antialias: true
Xft.rgba: rgb
Xft.hinting: true
Xft.hintstyle: hintslight

    • If using .Xprofile, add the following:

      export DPI=96 # Or a different DPI value
xrandr --dpi 96 # Or a different DPI value

    • After editing these files, log out and log back in for the changes to take effect.

Explore the xfce4-settings-editor

  1. Open the XFCE settings editor: Run xfce4-settings-editor in a terminal.
  2. Navigate to xsettings and look for DPI-related settings. Experiment with different values, but be cautious, as incorrect settings can lead to display issues.
  3. Specifically look at the /Gdk/DpiScale and ensure it’s correctly set or reset it.

Investigate Compton/Picom Compositor Settings

If you’re using Compton or Picom (a fork of Compton) as your compositor, its settings can affect rendering quality.

  1. Locate the Compton/Picom configuration file: This file is typically located at ~/.config/compton.conf or ~/.config/picom.conf.
  2. Adjust scaling-related options: Look for options like scale-method or xscale-method and experiment with different values (e.g., nearest, bilinear, lanczos). The nearest setting often produces the sharpest results, but can also introduce aliasing.
  3. Disable or enable vsync: Try disabling or enabling vsync to see if it affects blurriness.
  4. Restart Compton/Picom: After making changes, restart Compton/Picom for the changes to take effect. You can usually restart it by killing the process and then running the command again (e.g., killall compton; compton &).

Consider Switching to a Different Display Manager

While less likely to be the primary cause, the display manager (e.g., LightDM, SDDM) can sometimes influence display behavior. Experimenting with a different display manager might reveal compatibility issues.

Test Wayland (Experimental)

While XFCE’s Wayland support is still experimental, it’s worth testing to see if it resolves the scaling issue.

  1. Install necessary packages: You may need to install Wayland-related packages (e.g., xwayland).
  2. Choose Wayland session at login: At the login screen, select the “XFCE on Wayland” session (if available).
  3. Evaluate scaling quality: Test the scaling quality under Wayland. Be aware that some applications may not function correctly under Wayland.

Hardware Acceleration

  1. Check if hardware acceleration is enabled: Open a terminal and run glxinfo | grep "direct rendering". If direct rendering is enabled, the output should say “direct rendering: Yes”.

  2. Enable hardware acceleration if it is disabled:

    • Nvidia: Open the NVIDIA X Server Settings application and make sure that “Force Composition Pipeline” is enabled.
    • Intel: Install the mesa-utils package and run sudo intel_gpu_top. This will show you the GPU usage. If the GPU usage is low, then hardware acceleration is not enabled.

Investigate Monitor EDID (Advanced)

In rare cases, the monitor’s EDID (Extended Display Identification Data) can cause scaling issues. EDID contains information about the monitor’s capabilities and supported resolutions.

  1. Extract EDID data: Use a tool like get-edid to extract the EDID data from your monitor.
  2. Analyze the EDID data: Examine the EDID data for any inconsistencies or errors.
  3. Override EDID (Expert Users Only): As a last resort, you can attempt to override the EDID data with a custom EDID file. This is an advanced procedure and should only be attempted by experienced users.

Comparing Mint XFCE and Zorin OS XFCE

The original poster noticed that Zorin OS XFCE handled scaling without blurriness, whereas Mint XFCE had artifacts. The reasons for this difference might be the following:

  • Driver Versions: Different driver versions are used. Zorin OS might use newer or more finely tuned graphics drivers out-of-the-box.
  • Kernel: Zorin OS might use a different kernel version, and therefore have better hardware compatibility.
  • XFCE Version and Configuration: Zorin OS might have tweaked the XFCE configuration more than Linux Mint, leading to better default scaling behaviour.
  • GTK Theme: Zorin OS most likely uses a different default GTK theme than Linux Mint.
  • Preinstalled Packages: Zorin OS might ship with some additional packages that enhance rendering quality that Linux Mint does not.
  • Compositor Settings: Zorin OS might have a different compositer with specific settings that makes fonts look better.

To investigate this, one can boot into a Zorin OS live environment, and then investigate all of the above settings. It can be a tedious but useful exercise.

A Note on Fractional Scaling

As mentioned earlier, fractional scaling (scaling values that are not integers) is inherently more prone to blurriness. If possible, try to use integer scaling factors (e.g., 2.0 for 200% scaling) to minimize artifacts. Alternatively, adjust the font DPI and UI element sizes individually to achieve the desired level of magnification without relying on fractional scaling.

Final Considerations

Resolving scaling issues in Linux Mint XFCE often requires a combination of persistence and experimentation. By systematically working through the troubleshooting steps outlined in this guide, you can identify the root cause of the blurriness and implement a solution that provides a crisp, usable desktop environment. If everything fails, consider alternatives like using a different desktop environment (e.g., KDE Plasma, which has excellent scaling support) or a different distribution.

We are confident that by diligently following these steps, you will overcome the scaling challenges and enjoy a sharp and clear display on your Mint XFCE system. Remember to reboot your system after major changes to ensure the settings take effect.

revWhiteShadow kts personal blog site