Blur appears to overlay on top of the original

[PixlOne]

Platform: Arch Linux, Linux kernel 5.5.8

GPU, drivers, and screen setup: AMD Radeon RX 480, mesa 19.3.4-2, two 1920x1080 monitors configured side-by-side with xrandr

Compton version: picom wgit-e0149 (latest build from the feature/dual_kawase branch)

Compton configuration: https://pastebin.com/Rw2h1cHF

Steps of reproduction

Launch picom with --experimental-backends, blur-background enabled, the blur method set to "dual_kawase", and the blur strength set to 5.0 or higher. This issue also occurs with box and gaussian methods and is visible with high enough strengths/deviations.

Expected behavior

This should blur the background entirely, similar to how it works with blur strength set to 2.0 but more intense.

Current Behavior & Other details

The blur effect appears to overlay on top of the original background giving it a sort of "glowing" effect as shown here. As the blur strength increases, this glow effect becomes more apparent.

I've tested this on Openbox and XFCE and they both have this issue.

[tryone144]

This looks similar to #25. Please try changing line 67 in your config from

# blur-background-fixed = true;

to

blur-background-fixed = true;

You have set the window opacity manually with your opacity-rules. If blur-background-fixed is not set to true (the default is false), the blurred background is only applied with the window's opacity leading to the observed "glow"-effect. This might be useful when (inactive) windows fade in and out to not leave a blurred frame when the window is close to fully transparent (see #2 for a more in-depth discussion). In all other cases you want to enable this option.

[PixlOne]

Thank you, that fixed it.