Comment 10 for bug 1069183

That should be everything I need to test this.

I suspect a one line change (to turn off smooth scaling on the background image) will fix everything. I now have the images and can test. Alternately I could maybe cache a scaled png version. I'll see how well this first fix works.

Actually when I first went through benchmarking LightDM having a JPEG background (1920x1280) caused the processor to spend as much time decoding the JPEG as it did doing everything else. (JPEG can have up to ~6000 CPU calculations for each block of 8x8 pixels. My day-job is about image compression, I could go on for hours) . It'l be slowing down your load time too.

Thanks again for the extensive investigation.

Tracking on KDE's bugzilla here: https://bugs.kde.org/show_bug.cgi?id=308738