Bug 490353

Summary: Region screenshot results in image bigger and blurrier than reality (Wayland, multimonitor, fractional scaling)
Product: [Applications] Spectacle Reporter: Andrea Ippolito <andrea.ippo>
Component: GeneralAssignee: Noah Davis <noahadvs>
Status: REPORTED ---    
Severity: normal CC: kde.vacant701, kde
Priority: NOR    
Version: 24.05.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: blurry-screenshot

Description Andrea Ippolito 2024-07-16 11:48:43 UTC 
When capturing a rectangular region with Spectacle, the resulting image is blurry and bigger than reality as if it had been scaled up.

I have a laptop (secondary) and an external monitor (primary), with display resolutions and scaling % as follows:
laptop display 2256x1504@120%
external monitor 2560x1440@100% -> this is where the capture happens

The problem is visible as soon as you open the captured screenshot (for example in Gwenview) and although it's shown at its original size (100%), it's bigger than the real content. The only explanation is that spectacle actually produces a scaled up capture of that region of the screen.

You can refer to the attachment here to see what I mean:
https://bugs.kde.org/attachment.cgi?id=171691

System info:
Operating System: openSUSE Tumbleweed 20240714
KDE Plasma Version: 6.1.2
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2
Kernel Version: 6.9.9-1-default (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840U w/ Radeon 780M Graphics
Memory: 30.7 GiB of RAM
Graphics Processor: AMD Radeon 780M
Manufacturer: Framework
Product Name: Laptop 13 (AMD Ryzen 7040Series)
System Version: A7

Thanks!
Comment 1 Noah Davis 2024-09-18 19:32:36 UTC 
This should be fixed in Spectacle 24.08, except for when two screens with one having a larger fractional scale factor are saved in the same image. In that case, the image is always scaled to an integer scale factor so that integer scale factor screens are always sharp.
Comment 2 ZenithMonk 2024-09-18 19:44:04 UTC 
Created attachment 173843 [details]
blurry-screenshot
Comment 3 ZenithMonk 2024-09-18 19:44:40 UTC 
It still happens on my machine.

When I capture a rectangular zone on my external monitor scaled at 90%, the selection zone is blurry and the resulting screenshot is blurry too.

My configuration : External monitor, scaled at 90%, used a primary display while in docking station mode. Laptop display is disabled by default in docking mode (100% scaled on mobile usage).

(My bad for adding the screenshot without context.)

System info:
Operating System: Arch Linux
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.7.2
Kernel Version: 6.10.10-zen1-1-zen (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i5-8400H CPU @ 2.50GHz
Memory: 15,4 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 630
Spectacle version: spectacle 24.08.1-1